SPIDERS And Their Kin - A Golden Guide by Ana C. Ponticelli

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by HERBERT W. LEVI

Museum of Comporotive Zoology Horvord University

and LORNA R. LEVI

Under the editorship of HERBERT S. ZIM

Illustrated by NICHOLAS STREKALOVSKY.

� .,

GOLDEN PRESS

•

NEW YORK

Western Publishing Company, Inc. Racine, W isconsin

FORE WORD This small guide to spiders and their near relatives intro duces the various groups and shows their great diversity. Accurate species identification is often a problem even for specialists, and while the groups treated in this guide are widespread, some of the species illustrated have a limited distribution. If they are not found where you live, perhaps you will find spiders that are similar. The scope of the book is broad enough to make it useful in Europe and on other continents The book wou ld have been i m poss i b le without the h e l p of numerous friends and colleagues. Among those who read early drafts of the text were Harriet Exl i n e Frizzell, W . J. Gertsc h , 0. Kraus, Nell B . Causey, and R . Crabil l . Mr. N . Strekalovsky made the i l l ustrations, often hand i capped by l i m itations of live source materia l . Superb color s l i des of European spiders were made ava i l a b l e by J. Potzsch; slides of many uncommon species were loaned by H. K. Wal lace. We sincerely thank all these and also the many who provided living ani mals , color photographs, determ i nations of unfa m i l i a r a n i m a l s , or help with the text: J. W . Abalos, G . Anastos, J. Beatty, A . R. Brady, P. Bonnet, Stephanie Cannon, Nell B. Causey, B. Conde, J . A . L . Cooke, f. A . Coyle, J . Davi s, C . D . Donda l e , L . C . Drew, W . Eberhard , T. E i sner, G . S . F i c hter, B . T. Gardner, G. P. Ginsburg, L . G latz , B. Heydema n n , R . L. H offman , H . Homann, B. J . Kaston, H . K ling e l , G. M . Kohls, R . Konig, D . H . Lamore, Z . Maretic, J . Martens, M . Melchers, Rodger Mitche l l , W . B . Muchmore, M . H. Muma, F. Papi , B . Patterson, J . Rafa lski , J. Redd e l l , Jonathan Reiskind, V. D . Roth, J . H . P. Sankey, P. San Marti n , P. Stough , V. Silhavy, W . D. Sill, H . Stahnke, T. W. S u m a n , D. W. Sissom, W. A . Shear, Paolo Tongiorgi, M . W . Tyler, J. D . U n z i cker, M. Vachon, A . A . Weaver, G . C. W heeler, P. W ill, T . A . Woolley. H . L. L. L.

1990 Edition ©Copyright 1987, 1968 b y Western Publishing Company, Inc. All rights reserved, including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge retrieval system or device, unless permission in writing is obtained from the copyright proprietor. Produced in the U.S.A. Published by Golden Press, New York, N.Y. Library of CongressCatalogCard Number: 68-23522. ISBN 0-307-24021-5

C ONTE NTS

SPIDERS AND THEIR KIN, classification, a natomy, cou rtship,

growth, e n e m ies, silk, poisonous spiders COLLECTING, p reservi ng, rea ring .................

4-17 18-19

4 p a i rs of legs, s p i n n e rets; cepholothorax a n d ab足 d o m e n joi ned by na rrow waist; no a ntennae .. 20-115 Myga/omorph Spiders, Orthognotha: chel icerae (jaws) at足 tached in front of head, o p e n fo rwa rd . 20-25 True Spiders, Labidognatha: chel icerae atta c h ed below head, open to sides 26-115 Cribe//ate Spiders: cribe l l u m , a plate with spigots, in front of s p i n n e rets . 106-115

SPIDERS:

SPIDER RELATIVES: no a nte n nae, no spi n ne rets on posterior

of a bd o m e n ; 4 pairs of legs .................................. ... .... . 116-140

116-117 118-119 Pseudoscorpions: l a rge p i n ce r-like pal ps, lacks sti nge r . 120-121 Scorpions: l a rge pincer-like pal ps, slender tail, with stinger 122-127 Whipscorpions: strong p a lps, long w h i p l ike forst legs .

Windscorpions: h uge jaws, leglike pa l p s .

Harvestmen: compact body, segmented abdom e n , eyes usu-

a l ly on a tubercle . Mites: s m a l l , body com pact, abdomen usua l l y u n segm e nted Microwhipscorpions: small, leglike pal ps, long ta il . Ricinuleids: hood covers jaws . .

MYRIAPODS: 1 p a i r of a ntennae, legs on a series of s i m i l a r

ri ngs Pauropods a n d Symphyla: 9- 1 2 pa irs of l egs . Centipedes: 15 or more pai rs of legs, o n e on each segment Millipedes: two p a i rs of legs o n most body ri ngs

LAND CRUSTACEANS: two pairs of a ntennae . Wood Lice: flattened, lack ca ra pace .. Land Crabs: not flatte ned, cepha lothorax with ca rapace .

MORE INFORMATION INDEX ...

128-133 134-139 140 140

141-151 141 142-145 146-151 152-154 152-153 154 155 156-160 3

SPID ERS

AND

THEIR KIN

About 37, 000 species of spiders have been named so far, representing what is bel i eved to be a bout one-fourth the tota l . Some 3 , 000 kinds a re known from E u rope; fewer from less-studied N . A . The 700 species of spiders found in N ew York and N ew Eng land about equals the species of birds breeding in N . A . north of Mexico . Spiders a re members of the phylum Arthropod a , the l a rge group of ani mals with jointed legs and a hard outer skeleton . They belong , more specifica l ly, to the class Arachnid a , which inc ludes animals with four pairs of legs, no antennae or wings, and only two body reg ions-a ceph a lothorax and an abdomen. Arachnids and two sma l ler ma rine arthropod g roups (pp . 6-7) form the sub足 phy l u m Chelicerata . These arthropods ali possess chelicer足 ate jaws {pp. 8, 20, 26) which sometimes a re mod ified into pincers as in windscorpions (p. 1 1 8- 1 1 9) or into piercing stylets, as in some mites { p . 1 34). A l l other arthropods have antennae, and mand i b l es that work against each other. They a re p laced in six c lasses. These inc l ude the insects {class Insecta) , which have three body reg ions, three pa i rs of legs, one pair of antennae , and often wings; t h e crustaceans (class C rustacea ) , ma inly water-dwel lers-the crabs, lobsters , shri m p , ba rnac les, and water fleas; and the myriapods: centi pedes . (class C h i lopoda) and m i l l i pedes (class Diplopoda); and c l asses Symphyla and Pauropoda found in habitats l ike those of spiders . In spiders, the a bdomen is attached to the cepha lo足 thorax by a na rrow sta l k ; in scorpions, harvestmen, and mites, the attachment i s broa d . Spiders usua l l y have e i g ht simple eyes, variously a rranged , and some have a cute vision. Scorpions have both median eyes and (usua l l y) 4

lateral eyes; harvestmen, only median eyes; pseudo scorpions, lateral eyes or none. Long setae (hairs), sensi tive to vibration, air movements and sound, occur on the legs of some spiders and on the pedipalps of scorpions and pseudoscorpions. In spiders the abdomen shows little or no segmentation, but segments are distinct in scorpions. The segmented spiders, suborder Mesothelae, family Liphistiidae (p.

7),

are an exception. These spiders live in burrows in the soil and are only found in East Asia. In the other sub

20) and Labidogna 26), vestiges of the segmentation thought to char

orders of spiders, Orthognatha (p. tha (p.

acterize ancestral forms is reflected externally by the pattern on the back of the abdomen and sometimes by the presence of several hard plates (sclerites); internally by the muscle arrangement and structure of the. heart. This book treats the land arthropods other than insects. Of these, the spiders and mites, both of the class Arach nida, are the most abundant. Mites are mostly microscopic and difficult to study, hence are given little attention here. The graphs below show the number of species in major groups of arthropods and arachnids. ARTHROPODS

ARACHNIDS

ARTHROPODS

evolved from m a r i n e seg m ented worms. Foss i l s do not reveal whether they evolved from d ifferent stocks or a l l from one group. Onychophorans, represen ted by the ma n y-legged, soft路 bodied Peripatus m a i n ly of the Southern Hem i sphere, are perhaps s i m i l a r to so me a ncestor. The g r o u ps of a rthropods a n d t h e i r prob颅 a b l e relationships are shown a b ove. The most wor m l ike arth ropod s are certa i n centipedes (p. 142)

ARTHROPODS

Ricinuleids

that consist of series of s i m i l a r segme nts. In other arthropods, groups of segments have become special ized . In i n sects, one gro u p of seg路 m e n ts forms the head; a nother, the thorax; a t h i rd, the abdomen. Two m a r i n e gro u p s related to the arac h n ids are i n c l u d ed i n t h e subphyl u m C h e l icerata: horseshoe crabs, which l i v e only on th e east coasts of Asia a n d N.A.; a n d sea spiders, w h i c h are s low m a r i n e creatures that f e e d on hydroids, a n e mones a n d o t h e r sea a n i m a ls.

T H E S P I D E R'S BODY consists of a cephalothorax, cov ered by a carapace (shield), and an abdomen. Four pairs of legs are attached to the cephalothorax. The legs end in either two or three claws, varying with the family. Nearly all spiders have eight simple eyes. Their arrange ment, important in identifying families, is shown in black and-white diagrams with family descriptions. The shape of the carapace is commonly distinctive, too. The cephalothorax (combined head and thorax) con

1 6), and stomach. In 1 3) are the heart, digestive tract, repro

tains the brain, poison glands (p. the abdomen (p.

ductive organs, lungs and respiratory tracheae, and silk glands. The two parts are connected by a thin stalk, the pedicel, through which pass the aorta, intestine, nerve cord, and some muscles. Spinnerets (usually six) issue strands of silk through tiny spigots. Between the front pair in some spiders is the colulus, its function unknown. In cribellate spiders (p.

1 06), the cribellum is here.

THE JAWS, or chelicerae, a re in

the front of the head in Orthog· n atha (p. 20) and i n the Meso thelae (p. 7), below the head in other spiders. Spider jaws are tipped by fa ngs, with a d uct from a poison gland ope n ing at the end of each. In front of the l a bium (lower l ip) is the mouth, · its opening covered by the l a brum ( u pper l ip). Spiders feed o n l iving prey, which may be para lyzed or killed w ith poison . J u ices from the d i· gestive glands l iquefy the prey before it is sucked into the mouth by the stomach's pum ping action. S p iders with few teeth an their jaws may suck out the insides of prey and d iscard the empty shell .

betwee n the jaws and the first legs, are smal l and leglike in females a n d in you n g spiders. I n males, t h e tip i s en l a rged. Before searc h ing for a female, the m ol e d eposits a d rop o f sperm on a specia l web, then sucks it into the palp. I n matin g , the sperm is trans ferred by inserting the pa l p into an open ing on the undersid e of the female's abdomen. In most spiders, this ope n ing is on a hard plate, the epigynum, just in front of a slit (gonopore) through which the eggs pass. Some, called ha plogyne s p iders (pp. 26-30), lack a n e p ig y n u m ; the palpus is inserted d irectl y into the go nopore.

PEDIPALPS,

chelicera

end ite

cymbium

a nal tubercle

trochanter

FEATURES shown above are used in the text to describe fam il ies and species. Measurements g iven in this book are of the a d u lt spid er's approximate bod y length, exEXTERNAL

eluding legs a n d jaws. They a re not measurements of leg span. All spiders show ind ivid u a l and reg ional d ifferences in size. The sig n !;? is used for female, iS for male.

COURTSHIP by the adult male begins after his palp is filled with sperm (p.

8) and he has found a female.

Some hunting spiders locate mates by finding and following the draglines (p.

1 5) laid down by mature

females of the same species. Experiments have demon足 strated that male web spiders can often tell by touching the web whether it contains a mature female. Male orb weavers and other web spiders with poor vision announce their approach by plucking the strands of the female's web. Others stroke and tap the female cautiously. Spiders with good vision, such as wolf spiders (below) and the brightly colored jumping spiders, dance and wave their legs before their mates. A nursery web spider (p.

78)

presents his mate with a fly, before mating. A female does not ordinarily feast on her mate, as many people believe, but males usually die soon after mating. Some male and female sheet web spiders (p.

46)

live together in the same web. After a week or more, the mated female deposits her eggs in a silken sac (p.

1 4) . Some species make several

egg sacs, each containing several hundred eggs. Species that take care of their eggs or young usually produce fewer eggs. Weeks later, or sometimes not until the fol足 lowing spring, the young spiderlings emerge.

Courts h i p of wolf spid e rs Pardosa nigriceps

A spider shed d i ng its skin

GROWTH of a spider requires shedding its exoskeleton, usually

4 to 1 2 times before maturity. Female mygalo足 20) continue to molt once or twice a

morph spiders (p.

year through their long adult lives. Before a spider sheds, the inside layers of its skeleton are digested. The remaining skeleton then tears more easily.

As molting begins, increased blood pressure

causes the skeleton to tear at the front edge, continuing around the carapace, which then lifts off; the skin of the

abdomen splits. A pumping motion lowers and raises leg spines, making the old skin slip over the flexible new legs. In the process of molting, a previously lost leg may be replaced by a new, smaller leg.

Most spiders live one or two seasons. Orthognath spiders do not mature for several years; the males live less than a year thereafter, but the females may live up to

20 years. Some primitive spiders (such as Sicarius, 5 to 1 0 years.

Loxosceles, and Filistata) may live

E N EMIES of spiders include other spiders (pp. 50, 5 1 ) a n d some kinds of insects and birds. These enemies help to control spider populations, which are affected also by pa rasites a n d avai labi lity of food . The spiders in turn control to some d egree the abundance of the prey they feed on, usua l l y insects. of some species prey only on spiders belonging to pa rticular families or genera. Below, a female wasp, Anop /es fuscus, is stinging a wolf spider, Trochosa fe rrico /a ( 1 ). ( Rarely the spider is the victor ir. these bat路

WASPS

ties.) The wasp then carries the spider to her previously exca路 voted burrow (2) and lays an egg on it (3). The wasp larva feeds on the paralyzed spider (4), eventually to p u pate a nd metamorphose into an adult.

Potzsch

p roduced by spiders is used in many ways (pp. 1415). Pseudoscorpions (p. 120), spider mites (p. 135), most centipedes (p. 142), and some millipedes (p. 148) a lso produce si l k but only for mating or for egg and larva l cham bers. The caterpil lars of many moths spin si l k for their cocoons. SILK

CH EMICALLY silk is a fibrous pro颅

tein (fibroi n), insoluble in water. It comes from spigots of the spin路 nerets in liquid form and hardens immediately, polymerizing as it is pulled out. Silk may stretch as much as one.fourth its length before breaking, and the silk of Nephi/a (p. 65) is the strongest natural fiber known. Spider silk is not used commercially as the predatory habit of spiders makes it d i fficult to rear them in large numbers. Web spiders prod uce d ifferent types of sil k from fou r t o seven a bdominal g l a n d s : vis路 cid or sticky silk from some, web frame threads from others, egg sac sil k from stil l others.

CLAWS on the tips of the legs

are used by the spider to handle silk. The claws pivot back and forth, hold ing the silk between middle claw and two flexible setae (accessory claws). What prevents silk from sticking is not known . Spiders that build webs and walk on silk threads have three claws on each leg. However, many hu nting spiders have only two claws, for in place of the middle claw is a tuft of flattened hairs. Some also have a brush of hairs (scapula) u nd e r each leg's last seg ment. The claw tuft adheres to the water fi l m cover路 ing most su rfaces, permitting a spider to walk an smooth areas.

Spider Anatomy

heart claw tuft

book l u ng cover median claw

Zora spinimana, European Cten idae, (0.211 ), guarding egg sac

MANY USES OF SILK have evolved. Most spiders make silken egg cases, often spherical but sometimes flattened discs or stalked. Some species use silk to make a nursery

78). Many hide in silk tunnels or use 22). Prey may be caught in webs, or snares, then wrapped (p. 53).

for spiderlings (p.

silk to line their burrows, or for trapdoors (p.

of Argiope bruennichi is shown below. The eggs are first stuck to a sil k platform, then cov足 ered with threads. After they are

EGG SAC

wra pped in loose silk, a final cover of dense, colored sil k is a dded. Argiop e suspends the egg sac from vegetation.

Potzsch

bal looning spid e r

spiderlings climb onto fence posts or branches and release sil k. As the l ine lengthens, the wind l ifts the l ittle spider off its perch and floats it off to a new area. The masses of ballooning threads seen on fa l l d ays are coiled gossamer. BALLOONING

of web spiders are a u n ique use of sil k for tra pping insects. Each kind has its special method of catching potentia l vic路 tims. Among them a re cobwebs, sheet, f u n nel, and orb webs. Spiral sil k in orbs is sticky in some, woolly in oth ers (p. 1 06) . SNARES

DRAGLINES of sil k are laid down by most spid e rs. Faste ned at in路 tervals, they may serve as sa fely l ines or to retrace a path.

web of Ostearius on drag l in e

Meta segmentata

Potzsch

poison g lands

chelicera

fang

coxa

Cephalothorax of Widow

(legs removed)

POISONOUS SP IDERS,

specifica l l y those dangerous to man, are few in n u mber. In the U nited States a nd Can足 ada, fata lities from wasp and bee stings far outnumber those from spider bites and scorpion sti ngs. Few spiders wi l l bite even when coaxed, and the bites of most of those larg e enough to penetrate the skin p roduce no harm at a l l . Knowledge a bout spider venoms i s very limited. Often a spider that bites is i m m ediately destroyed or escapes. Even if the bite causes i l l ness, the spider may not be positively identified. I n th e U.S., the da n gerous spiders i nclu d e the Widows a n d the Brown Spi ders. Bites of Cheiracanthium (p. 89), small wh itish spi ders fou n d in most parts of the world, may produce a slight fever a n d destroy tissues around the bite. The venom of a Brazi lian Wo lf Spider, Lycosa ra ptoria, a lso destroys tissues i n the vicinity of the bite, while a nother Brazi lian spid er, Plroneutria (p. 91 ) , has a very painful nerve poison. The Funnelweb Myga lomorph (Atrax, p. 24) and a n u m ber of other Austra lian my足 ga lomorphs a re dangerously poisonous. 16

Latrodectus mactans

� 1 1 mm (0.5 " )

WIDOWS are web spiders. The

sedentary females may bite if molested. Males move about but do not bite. The Black Widow (Latrodectus macfans) is found in most warm parts of the world (p. 42) . Related species occu r north to southern Canada and also in southern S. A. The bite may g o unnoticed a nd may not h u rt. But the su bseq uent severe a bdom inal pain from a Black Widow's bite resembles ap· pend icitis. There is pain also i n muscles a n d i n t h e soles o f the feet, but usually no swelling at the site of the bite. Alternately, the sal iva flows freely, then the mouth is d ry. The bite victim sweats profusely. The eyel ids are swollen. The patient usually re· covers after several days of agony. Physicians can rel ieve the severe pain by i njection of calci· um g l uconate. A ntive n i n is avail able i n a l l countries where bites occur freq uently. No fi rst aid treatment is available for any spider bite.

SPIDERS (Loxosceles laefa) of Chi le, Peru, and Ar gentina have been known since the 1 930's to ca use severe i l l n ess. It was not until the 1 950's, as a result of bites in Texas, Kan sas, Missouri and Oklahoma, that the sma ller Brown Recluse Spider (L. reclusa) was recogn ized to be similarly toxic. This spider com· manly l ives in h. o uses on the floor or behind furniture. Bites occ u r when a spider rests in clothing o r i n a towel. There m a y be no harm at all. In very severe cases, a red zone appears a round the bite, then a crust forms and falls off. The wound grows deeper and does not heal for several months. Other species of Loxosceles are found in southwestern U. S. and i n Mediterra nea n cou ntries (p. 29). Probably because these spiders do not have contact with man, accidents d o not occur. I n any bite from a spider known ta be poisonous it is wise to consult a physician as soon a s signs of ill ness appear. BROWN

COLLECTING SP IDERS can be done nearly everywhere in houses, gardens, fields and woods, under bark, stones, or logs. Turn stones and logs back so the habitat is not destroyed. Spiders that run along the ground can be chased into a glass vial or picked up and dropped into a vial of alcohol. Each collecting vial may be half-filled with specimens. Be sure to insert a penciled field label, citing locality, date, and collector. SWEEPING

shrubs and herbs with an insect net is a tech n i que by which many spiders can be col lected . Small spid ers can be sifted from leaf litter by using a shaker with cloth sides and a 1 em (V.. 11 ) screen bottom . Bu rrowing spiders m ust be dug out.

buried flush with the g round su rface wil l trap r u n n i n g spiders. P u t in t h e can a small amount of ethylene g lycol (anti freeze), wh ich does not evapo rate. A ra ised l id su pported by stones preve nts di l ution by ra i n . Empty once a week.

COLLECTING with a m i ner's hea d l a m p yields a ha rvest of wolf spid ers, whose eyes reflect l ight, and of nocturnal orb weav ers that show u p agai nst the dark backg round. Small spiders that h ide i n crevices by day sit i n thei r webs at nig ht.

FUNNELS have a 1 (V..") wire screen across the bottom. Leaf litter is placed on the scree n . Fu mes from a single mothba ll suspended below the lid will d rive spiders a nd other small a n imals down into a container of water or alcohol below.

NIGHT

tin can trap

A TIN CAN

TULLGREN em

T u l l g ren funnel

jar containing via ls

Jun!n: Terma

3l00rn, under bark 9 feb,l965 H,Levi

collecting label of spiders and their kin m ust be i n l iquid, either 80% g ra in alcohol or 70-80% isopropyl (rubbi n g ) a lcohol, as these a n imals a re soft-bodied a n d cannot be p i n ned a n d dried. I n sorting , keep specimens sub merged. Each l a beled species should be kept in a sepa rate vial and stored with others in a l a rger jar of alcohol.

PRESERVATION

LABELING is most im porta nt. Place a l a bel inside every via l . I nclude on t h e l a bel t h e date and l ocal ity (state, nea rest town ), col· lector's name, and habitat. Pen· ciled l abe l s are good i n the fiel d. Later replace with l a bels in I n dia i n k or typed. Use high qual ity

paper. Never collect more than you ca n labe l . A specimen with out a loca l ity l a bel is worthl ess. Gro und spiders can be kept in terra ria with soil . Or cut a n air hole i nto a plastic box with a hot knife, a n d g l ue screen ove r it. Web spiders can be kept in wooden frames with glass o r cellophane sides. T o prevent can n i balism, each spider m ust be kept i n a sepa rate enclosure. Spiders need water, but do not a l low containers to gel moldy. Many spiders d o not need food for days. Sp i ders a n d ce ntipedes will eat fl ies, mealworms, cock roaches; mil l i pedes a n d wood l ice, decaying vegetation. REARING

M Y G A L O M OR P H S Suborder Orthognatha

Mygalomorphs include the largest spi ders. There are a bout 80 species north of Mexico, m a n y more south; few in Europe. Their jaws (chelicerae), at tached on front of the head, move up and down, opening para l lel to long axis of body. All have 4 lungs (p. 25). HAIRY MYGALOMORP HS

rs> �

Cl? jaws closed

(Theraphosidae) a re com monly ca l led tarantu las in the U.S. Unfortunately, this name is shared with other spiders. Hairy Myga lomorphs are known a lso as Bird Spiders, a n d they may occasion ally catch nestling birds, liza rds, or sma l l sna kes. I n S. Africa, they a re ca l led Monkey Spiders. Most are not poisonous to man. About 30 species occur in the U.S., mostly in the Southwest, none in Europe. The largest, from the Amazon Basin of S. A., may be 6-9 em (3.5") long, with a 25 em (1 0") leg spa n Most Hairy Myga lomorphs live on the ground, but some dwe l l i n trees, others burrow. The eyes a re closely g rouped; these spiders are sensitive to vi brations and h unt at night by touch. Cornered, the spider may purr or rear u p on the back legs. The "hai rs" on the a bdomen, easi l y shed or ru bbed off by the legs, are very i rritating to human ski n . The underside of each leg tip has a pad of iridescent hairs. Young males look like fema les, but after the final molt, emerge slender and iridescent, palps developed. Captive fema les have lived 20 years and molt after maturity; males , shorter lived , d o not m olt. Mem bers of a related fa m i l y, Barychelidae (not i l l us trated), have a digging ra ke (p. 23) and make a trap door to burrow entra nce. 20

Aphonopelma eutylenum

southern California

These spiders show the d iversity among the Hairy Myg a lomorphs and also their com mon feature of hairiness.

Cyrtopholis sp. ďż˝ 50 mm (2 11 )

Puerto Rico

A. chalcodes ďż˝ 70 mm (2.711 )

Arizona

TRAPDOOR SPID E R S (Ctenizidae) are mainly tropical, but numerous species are found in the southern U.S. and a few in southern Europe. All are about

1 -3 em (0.3- 1 .2")

long. Using the spiny rake on the margins- of their jaws, trapdoor spiders dig tubelike burrows. The tube, includ ing the opening, is lined completely with silk. To make the trapdoor, the spider cuts around the rim of the open ing, leaving one side attached for the hinge. The top of the lid is camouflaged with debris, and additional silk is added under the lid to make it fit tightly. The lid may be held shut by the spider. When the spider feels the vibration of passing prey, it rushes out, captures the prey, and takes it down the tube. Except to capture prey, the female seldom leaves her tube; males wander in search of mates. Spiders in the small family Migidae (not illus trated), mainly Australian and South African, are similar but lack digging rakes. CYCLOCOSMIA are found in southeastern U.S. and southeast ern Ch ina. The spid er ma kes a fa lse bottom for its tube with the h ardened, squa red -off end of its abdomen and closes the top with a silken lid.

MYGALOMORPHS

MYRMEKIAPHILA of seve ral spe cies are fo und in southeastern U.S. The bu rrow, ofte n located i n a n ant nest, h a s a s i d e bra nch cl osed by a second door. The out side daor to the bu rrow is cov ered by a sil ke n l i d .

BOTH RIOCYRTUM fo u n d in C a l i fo rnia, is the most co m m o n l y col lected trapd oor spider. Ummidia (not i l l u strated) has its third tibia sad d l e-shaped . Several Ummidia are fo u n d in the southeastern states, where they d i g a l most horizonta l tubes i n to banks. The sim i l a r Nemesia is found i n south ern Europe.

Antrodiaetus burrow

FOLDING-DOOR SPIDERS, Antro

occ u r from the G u lf coast to Alaska. Tube dwel lers, they close their tubes by drawing i n the rim. Beca use the anal tu· bercle is some distance from the spi n n erets a n d there a re hard ened pl ates (sclerites) on the back of the abdomen, Antrodiaetus is i n its own family-An trodiaetidae.

dioetus,

MYGALOMO R P H S

F U N N E LWEB MYGALOMORP HS

(Di p l u ridae) a re easi ly recog nized by their long spi nnerets, which may be more than h a lf the length of the a bdomen. The spiders are up to 50 m m (2") i n size and most have only fou r spinnerets. Funnelweb Mygalomorphs catch i n sects by enta n g ling them i n a sheet of silk. The spider hides in a tube i n one corner of the sheet. The tube may be a mong the roots at the base of a tree or in crevices in rocks or wood . Funnelweb Myga lomorphs a re mainly tropica l, but a bout ten species are found in the U. S. and a few in Spain. Atrax is the poisonous Funne lweb Spider of Austra lia. The N . A. Microhexura is only 3 mm (0. 1 ") long. Beca use it has six spinnerets, Hexura is sometimes placed in a dif ferent fa mi ly, the Mecicobothriidae.

·- n · .· 'n ...

. . · .

;

.·

E uagrus spinnerets

.. : ·

�

�:

-�

Hexura f ulva

(0.5 11 )

U.S. Pacific coast

P U RSEWEB SPIDE RS (Atypidoe) ore about

1 0 to 30 mm (0.4- 1 . 1 ") long. The coxa of each polp is widened to form on endite, and these, as in all true spiders, serve as mouthparts. Sphodros, found from Kansas and Texas as for north as Wisconsin and New England, digs a hole at the bose of a tree and constructs a silken tube camouflaged with debris. The spider stays hidden inside the tube, which may extend

1 5 em (6") up the side of the tree. If on insect

lands on the tube, the spider bites through it with its huge fangs and pulls in the insect. The remains ore thrown out through the hole before it is patched up. In the northern states, moles ore found after June rains when they won足 der in search of females. The European Atypus constructs a small tube that resembles a half-buried root.

u n derside of Sphodros

a Europea n Atypus catching a fly

J.. :

,...-: i

TRUE S uborder

�

S PIDERS

labidognatha

closed

Most common spiders belong to this suborder, found

even in the Arctic. Their jaws (chelicerae) are attached below the head and open sideways, sometimes obliquely. With few exceptions, all have two lungs. carapace

e '

OONOPIDS (Oonopidae) are all less than

3 mm (0. 1 ") long. Most

are short-legged and have six tiny

eyes, closely grouped. Many have orange

plates

the

abdomen.

Oonopids live under stones or in litter and can run fast. Most are

20 species occur in U.S.; several reach north

tropical. About southern

�

ern Europe, some in houses. CAPO N I IDS mm

(Caponiidae) to 1 3 (0.5'') long, have only two eyes,

rarely eight in one group. The oval abdomen lacks lungs but has four respiratory slits. Found in litter and under stones, in tropics and south western

cara pace Nops sp. 'i' 6 mm (0.211) lesser Antilles

U.S.;

they

run

rapidly.

DYSDERIDS

(Dysderidae) have six eyes closely grouped, a long labi足 um, a n d four conspicuous respira足 tory slits, rather than two, on the underside of the a bdomen. All are noctu rna l . Segestria and Ariadna, but not Dysdera, direct three pairs of legs forwa rd, one pair back. Dysdera lives under stones or bark; it has long jaws, a n ada ptation for h u nti ng wood lice (p. 1 52). Others tra p insects in si lk strands radiating from the opening of a tubular re足 treat. About 1 0 species are found north of Mexico, more i n Europe.

DYSD E R I DS

S PITTING

side view of cephalothorax

SPIDERS (Scytodidae) can be recog nized by the shape of th e carapace. Underneath its dome is a pair of large g lands. With their secretion the spider squirts sticky threads at prospective p rey and holds it in place. The spider's aim is accurate up to 2 em (0.7"). Most species a re tropica l . The fe male carries her egg sa c in her jaws. Scytodes thoracica � 8 mm (0.311)

� cosmopol ita n ; buildings

SIX-EYED C RAB S P I D E R S (Sica riidae) extend their legs sidewa ys. They live on sa nd and ca n dig themselves into it to disappear completely. They a re found only in dry regions of S.A. a nd South Africa.

BROWN S P IDERS

(Loxoscelidae) a lso have six eyes. The thorax is not domed, however, and the spiders do not spit. They weave a sheet of sticky si l k i n which t h e y enta n g l e insects. LoxoÂ sceles reclusa (p. 1 7), in the U.S., and the larger L. laeta, i n S.A., may live in houses i n association with man. Their bite is poisonous . Eggs are i n a loose sac in the web.

Loxosceles laeta ďż˝ 25 mm ( 1 11 )

South America Loxosceles of several similar species occu r in southwestern and southcentral U.S. L. rufescens, of Med iterranean a rea, l ives under stones away from houses. poisonous 1. reclusa

. other

Loxosceles species

cara pace

DIG UETID S (Diguetidae) are related to Spitting Spiders (p.

28) and also

have six eyes in three groups. The cephalothorax is long, the abdomen hairy. The few species known are from southwestern U.S., Mexico, and Argen足 tina. All members of this family make a vertical silk tube above a maze of threads in desert shrubs.

PLECTREURIDS

(Piectreuridae)

have

eight eyes, thick legs, three claws. Like other haplogyne spiders (pp.

8, 26-30),

males have simple palps, females no epigynum.

Under stones in webs in

southwestern U.S., eastern Mexico.

ZODA R I I DS (Zodariidae) are a diverse group of eight eyed hunting spiders. Altogether there are about

300

species. Unlike haplogyne spiders, male Zodariids have a complicated palpus, and the females have an epigy num.

Unlike the Palpimanids, their legs are usually

equally thick, and they may have more than two spin nerets. Commonly the first spinnerets are large, those to the rear, small. Zodariids hide under stones or burrow in sand; no species is common in N.A.

s p i n n e rets

PALPIMAN IDS (Palpimanidae) are eight-eyed spiders that resemble Zodariids but usually have only two spin nerets. The heavy first pair of legs is carried up when walking. The sternum surrounds first segments (coxae) of legs. They make irregular webs under stones and de bris. The family includes about

80 species; none in N.A. scle rite spi n n e ret

a n a l tube rcle

�..:::::::3\

.-w1 0J) -� � 31

Cara pace s

Pholcus

Spermophora

Physocyclus

u Leplonela

0 Ochyrocera

DAD DY-LO N G-LEGS S P I D E R S ( Pholci dae, not to be confused with Pha l a n g i i d a e , p . 132) have unusua l l y thin, long , slender legs with flexible end s . Most species are whitish or g ray. A few have six eyes i n two groups of three. Others have eight eyes, the front center pair s m a l l . The eyes a r e a l w a y s c l o s e together. Many o f these spiders hang upside down i n a loose web in dark corners of houses or cellars. Others live under stones i n the dry a reas of temper ate and subtropica l regions . Males and females are commonly found together. Ma les have large, simple pal ps ; the fema les lack a n epigynum but have a swollen a rea on the underside of the abdomen . The female carries the round egg sac in her jaws . Of more than 300 species of Pholcids, a bout 40 species a re found in North America north of Mexico; a few occur i n north ern Europe and many in the Medi terra nean reg i o n . There are several other fa m i l ies of rare, sma l l (l-3 mm) (0. 05-0 . l ) , long legged spiders . These are mostly cave spiders-the Leptonetidae of the Med i t e r r a n e a n r e g i o n , Ja p a n , a n d v e r y rarely America ; a nd t h e Ochyrocerati dae, which i n c l udes a bout 20 tropica l and subtropical species found i n Amer ica , Africa, and Asia . Carapaces of representative genera..Ore at l eft .

DAD DY-LONG-LEGS S P I DERS

LONG-BODIED

CELLAR

SPIDER

hanging in its web shakes sa rapidly when ala rmed that both spider and web b l u r and seem to d isa ppear. I t is cosmopolita n, one of the commonest spiders found in cellars.

Pholcus face Pholcus phalangioides � 8 mm (0.3 11)

cosmopolitan; cellars carryi ng eggs

.... Psilochorus sp. � 4 mm (0.2 11 )

southern U.S.

SHORT-BODIED CELLAR SP IDER S pe rmophora meridionalis � 2 mm (0. 1 11 )

,, eastern U.S.; dark places

DADDY:LONG-LEGS S P I D E RS

UROCTEIDS (Urocteidae) of about a dozen species are found only in the Old World. They live under stones and in rock crevices, where they make a dense, flat silk tube up to 5 em (2'') wide or a series of sheets above and below the spider. Insects crossing the threads become entangled and are spun into the web as the spider, its spinnerets pointing in, runs around the insect. The prey is then cut loose and carried back to the center of the retreat. The egg sac is also placed between the layers of silk in the retreat. large urocteids resemble oecobiids (p. 1 15) in shape of head and spinnerets but lack the transverse plate, or cribellum, in front of the spinnerets, with which oecobiids spin their distinctive webs.

carapace

ďż˝

w face

spinnerets

UROCTEIDS

H E R S I L I I D S (Hersi l i idae) form a fam i l y of 7 5 tropical and subtropical species. They are 1 0- 1 8 mm (0 . 4-0. 7") long , with d isti nctively long spinnerets . Hersi liids position themselves head-down on bark or stone wa l l s . When a n i nsect approaches , the spider j u m ps over it, spreading s i l k and then rapidly c i rcles, spinnerets towa rd the prey, fastening it down . After the prey i s completely wrapped , i t is bitten and eate n . Mem bers of only one genus, Tama, are found i n southern Texas .

carapace

�.

........- �oorr--.

w face

COBW E B WEAVERS,

or Combfooted Spiders (Theridi足 idae), with more than 2,000 species, make up one of the large families of common spiders. More than 230 species occur in N.A. north of Mexico, fewer in Europe; many species are tropical and cosmopolita n . The American House Spider (p. 40) and the Widows (p. 42) are members of this family. C o bw e b Wea ve r s a r e u s u a l l y s e d e n t a ry, h a n g i n g upside-d own in the center o f a n irregular cobweb or hiding in a crevice at the edge of the web . Some make a small web beneath leaves, stones, or loose bark. The sticky outside threads entangle an insect that hits them and may pull it into the web as they contract. Using a tiny comb of brist ies (setae) at the end of the fourth leg, the spider throws silk over the captive, then bites and sucks it dry. .Cobweb Weavers have few or no teeth and do not chew prey, as do spiders of related groups. Most spiders in this family lack strong setae (hairs) on legs. Many have a spherica l abdomen, a lmost all have eight eyes, and a l l have three c laws on each leg (p . 1 3). As i n other web spinners, the male has poor vision and courts the female by plucking threads of her web .

Wt face

Theridion carapace

THERIDION, with several hundred species, is the second largest spider genus and includes many of the commonest small spiders from the Arctic to the tropics. All hang u pside d own in an irreg ular web. As in most spiders, identifi· cation of species d e pends on fea· tures of the palpi or epigynum, a matter for the special ist.

. sisyphium

-.,,:=��I"!"" (j? 4 mm (0.2 " ) Eu rope; low p COBWEB WEAVERS

_.....

Theridu/a emertoni

.111) - <;1 2 mm (0 eastern U .S. under leaves

ďż˝

Spintharus llavidus

eastern U.S. Ia Bolivia; vegetation

COBWEB WEAVERS

Dipoena nigra

_'/ � 3 mm (0. 1 11) � N .A.; ant feeder, on g round

4..

....

Co/eosoma Roridanum � 2 mm (0. 1 11 )

cosmotropical; l itter

Thwaitesia affinis � 5 m m (0.2 11 ) N ew World tropics;

vegetation

�

ARGYRODES a re tiny, often sil

ve r-colored spiders that l ive i n t h e webs o f othe r spiders. They feed o n their host's sma l l p rey or join them in a la rge mea l . Some have an elongated worm-shaped a bdomen and ca n wiggle its tip. Ma les have b umps (tu rrets) on their heads. About 15 species a re found north of Mexico, seve ral i n th e Med iterra nea n region, many i n the tropics. COBWEB WEAVERS

AMERICAN HOUSE SPIDER

ACHAEARANEA is a very large, world-wide genus recog nized by the patches and streaks often present on the sides of the ab足 domen. Some females have a h u m p on the abdomen. Males are smaller than females.

female l ives in a curled leaf hanging i n the web, and the tiny males hang nearby. The male a m putates one of his enormous palpi before his last molt. Two common species occur from southern U.S. to S.A. TIDARREN

COBWEB WEAVERS

E NOPLOGNATHA are a l l dark colored (except E. ovalo) a n d have a leaflike pattern on the abdomen. Some l ive in curled路up leaves, some u nder logs, others in leaf litter. Several species occur in N.A. and Europe.

usually a re brown with a white line arou nd the front of the abdomen. S . borealis sits in a crevice near the web. S . hesp era, of western N .A., and S. bip unc:tata, of Europe, are similar.

STEATODA

$. borealis

.6. c;? 8 mm (0.3") A eastern N.A.; tree trunks, buildings

S. erigoniformis

Ci? 3 mm (0. 1 " ) cosmotropical; under stones

WIDOWS

(Latrodectus) are the best known a n d la rgest of the Cobwe b Weavers. Severa l species a re found in the U .S., one i n southern Europe, and others i n the Nea r East and S.A. A l l a r e poisonous ( p p . 1 6- 1 7). Fema les a re a bout 1 2- 1 6 mm (0.5-0.6") long; males much sma l ler and with longer legs. Adu lt ma les wa nder i n search of fema les but do not feed or bite; fema les rarely leave their web. Stra nds of si lk are very strong.

BLACK W I DOW (L. mocto n s) is fou n d in wo rm sou thea stern U.S. and West I n dies a s for North as New York. I t is co mmon in tra s h , outhouses, a n d du mps. The spi路 der h o n gs in the we b, wh ich is u n der objects. I n North America many spider bites ore fro m Block Widows. S i m ilar species ore fou n d i n the western slates, Mexico, a n d oth er po rts o f the world. T h e

western North Am erica n species is L. hesperus. Both L. moctons a n d L. hesperus hove on hour颅 glo ss mark on the u n derside. The a bdo men of t h e Molm ignatte (L. tredecimguttotus), the northern Mediterra nean species, is marked with a series o f red spots. T h e you ng of a l l species ore br i ghtly colored with stripes a n d spots. The egg soc is brown and po pery.

tredecimguttatus

BROWN WIDOW (L. geometricusJ is cosmotropica l, i ntroduced in F l orida . Usua l ly they are brown to gray, some black; they a re found on ar near b u i lding Thou g h poisonous it is less l ikely to bite or injects less venom than other Widows. The egg sac is tufted, fluffy. RED WIDOW (L. bishopi) is fo u n d__ only in p a l m ettos in the sandy scrub-pine of centra l a n d southÂ ern F lorida. The wh ite, smooth. NORTHERN WIDOW (L. varia/us)

occurs from northern F l orida to southern C a n a d a ; com m o n in Britďż˝ ish C o l u m b i a . Genera l l y it is found in u n disturbed woods, in stum ps, or in sto ne walls. The egg sac is brown, pa per-like. The "ho u r g l a ss" is disti nct but usually broken.

L. moctans and ather species

DWA R F S P I D E R S A N D S H E ET-WEB W E AV E R S ( L i nyphi idae) form one of the largest fam i l ies of spiders, with more than 3 , 500 species. They are among the least known of a l l spiders, however. Like other web spinners, they have three claws on each foot, and most species build a dome-shaped or flat web . All have legs with strong setae, a row of teeth, . on each side of the fang g roove of the jaws, a nd a col u l us ( p .· 9) . DWA R F S P I D E R S (subfamily Micryphanti nae) of proba b ly severa l hundred species occur in N . A . north of Mexico. · They a re common in E urope , the Arctic, a nd on high mounta ins; the tropics a re bel ieved to have fewer species. Most Dwarf Spiders are less than 2 m m (0. 1") long , some less than 1 mm (0 . 05") long . Most make sma l l sheet webs . . The ma les of many Dwarf Spiders have unusual turrets, bulges, or depressions in the head reg ion . The a bdomen is usua l l y spherica l and, in some, i t i s covered with a hard , shiny p late . Some species a re abundant i n leaf l itter and can be collecfed in large numbers with a Tul lg ren funnel ( p . 1 8 ) . Many can b e found under stones; others can b e col lected by sweeping vegetation with a net . As many as 11, 000 spiders per acre (0 . 4 hectare) have been found in eastern U . S . , over 2 1/4 m i l l ion per acre (6 m i l l ion per hectare) i n a g rassy area in E ngland . These figures include a l l the differ ent species of spiders, but the Dwa rf Spiders make up two thirds of the tota l . T he g reat number of insects consumed d a i l y by such large populations of little predators i s difficult to esti mate . H ow wi l l this natura l food cha i n be affected by the spraying of i nsecticides over the countryside? It wi l l favor the i nsects, because the spiders lay fewer eggs and each generation takes longer to mature . 44

DWARF SPIDERS

11 () ?) • � (/ (/

side views of ·(9 Dwarf Spider cara paces

face

Erigane web 50 m m (2 11 ) d i a m . in depression

S H EETWEB

WEAVERS (subfamily linyphiinae) are mostly larger than Dwarf Spiders (p. 44) and usua l l y have a pattern on t h e a bdomen. I n contrast t o Cobweb Weavers, the a bdomen is usua l l y longer tha n wide, the legs may have strong setae, the jaws many teeth . The male and female often hang upside down under the same web and run rapid l y when disturbed. The webs, which have a few sticky th reads, a re found between branches of trees or bushes and i n high g rass, often in great abunda nce. If a n insect gets entang led, the spider bites from below, pulls the insect through the sheet and wraps it up. The web a lso protects the spider from pred足 ators from a bove, and someti mes a second web forms protection from below. O n l y a few of the m a n y species a re widespread and a bundant.

web 1 0 em (4 11 ) PLATFORM SPIDER

web 15 em (6 11 )

Frontine/lo pyromitelo

eastern and centra l Ca nada a nd U.S.

,----- -H6Nnda coccinea !j! 4 mm (0.2") so(i'fh,ea!if_er路n U .S.; g rass

Drapetisca socialis

Europe; others in N. A.

SHEETWEB WEAVERS

Stemonyphantes blauveltae

a 4.5 mm (0.2") N . America, debris

Balthyphantes pallidus

ďż˝

<;> 3 m m (O. l ") N . America; in webs in ground litter

SHEETWEB WEAVERS

PIRATE SPIDERS (Mi metidae) invade webs of other spiders. The slow-moving Pirate Spider bites the web owner, which is quickly para l yzed and sucked d ry through the legs, one after another. Some sit with outstretched legs under leaves waiting for passi ng spiders. One spe cies has been observed to pluck the prey's web like a courting male to gain entrance. Pirate Spiders are recognized by the row of strong curved setae on the front margins of the lower segments of the fi rst pair of legs. The eggs are left in a sta lked sac suspended from a twig or rock. This sma l l fam i l y in cludes a bout a dozen species north of Mexico.

Mimetus notius

� 6 mm (0.2 11 ) southeastern U .S.

N E ST I C I DS ( Nesticidae), often cal led Cave Spiders, a re pale denizens of moist caves and cel lars. They make a n irreg u l a r cobweb. The fourth leg h a s a c o m b on i t s last seg ment ( p . 36). Between the front pair of spinnerets is a colulus ( p . 9) . This structure, its function not known , i s found a l so i n s o m e Cobweb Weavers, b u t a l l o f these a r e dark spiders . T h e Female Nesticid spider carries her egg sac attached to her spinnerets . Thirty-one species of Nesticids occur north of Mexico . Relatives i n c l ude the m i nute Symphytognathidae (not i l lus足 trated) , the m i nute Archaeidae (Archaea, below) of Africa, and Mecysmauchenidae of South America .

Nesticus cellulanus

'i! 5 mm (0.2 11 ) N. Hem isphere

Archaea has

distinctive carapace and chel icerae. The chelicerae a re used to spear spiders.

Mecysmauchenius segmentatus

'i! 6 mm (0.211) Chile

NESTICIDS

O R B-WEAV E R S (Araneidae, often ca l led Argiopidae) form a fam i l y of some 3 , 500 species found i n all parts of the world . About 180 species occu r north of Mex足 ico. Al most a l l of these spiders spin a n orb-web, a n engi neering feat practiced also b y the U loborids ( p . 1 14) and by the related Ray Spiders and Tetrag nathids (pp. 70-7 1). Orb-weavers have poor visi o n . They locate prey by feeling the vibration and tension of the threads i n their web, then quickly turn the captive with thei r legs whi l e the i r fourth l e g s p u l l o u t silk and wrap t h e vict i m . T h e prey is bitten before being carried to the center of the web or to the spider's retreat in a corner, where it is eate n . Anything i nedible is cut o u t of t h e web and d ropped t o t h e g round . In the fa l l , female Orb-weavers of many species produce egg sacs conta i n ing several hundred eggs (p. 14), then d i e . In some species the eggs hatch soon; in others not unti l the fol l owing spri ng . The large number of eggs produced suggests that these spiderlings face greater hazards than do the young of scorpions, pseudoscorpions, and spiders cared for by the i r mothers. Orb-weaver spider l i ngs make a perfect orb-web, but as the spiderl ings mature, their webs become more spec i a l i zed and characteristic of the species. Orb-webs a re a favorite object of research i n i nsti nc足 tive behavior. Stra nds are pu l led back wh i l e the spider is working to learn how the spider compensates for the change. Or, as the spider builds a web in a frame, the frame is turned to determine the i nfluence of g rav足 ity on the position of the web . Changes in the web足 building pattern as the spider matures are studied , too . Sma l l doses of some drugs given to the spider on a f l y w i l l a l s o c a u s e t h e s p i d e r to c h a n g e t h e pattern o f its web . 52

ORB-WEAVERS

carapace

face

carapace

SILVER ARGIOPE Argiope argenfafa

g rasshopper ca u g ht in web is rapidly turned with first legs while fourth legs wrap it i n silk sheet d rawn from spin nerets l,l!ft:��.,:h,

Prey-handling By Typical Orb-Weavers

carries wrapped prey; will hang it u p or feed on it.

ORB-WEAVERS

ORB-WEBS a re built by many spe

cies at nig ht. First a bridge is made. The spider may walk from one bridgehead ta another, carryi ng along a line, but usually the spider sits with its abdomen in the air and l ets the wind p u l l aut a silk thread ( 1 ) . If the thread touches, a bridge is es· tablished (2); if nat, it may be p u l led back and eaten. When a bridge is establ ished, the spider may reinforce it by wal king back and forth, l aying d own more silk. Then the spide r d rops on a th read ( 3 ) it has fastened at the center of a stra nd in the bridge. It secures the verti· ca l thread and returns to the fork, the hub of the final web (4). A rad ius thread, attached at the hub, is ca rried up to the bridge and across a short d is· lance (5) before it is tightened and fastened (6). More rad ii are formed by the same proced u re 54

ORB-WEAVERS

(7-9), and the h u b may be strengthened with add itiona l threads before t h e spider starts a temporary spira l ( 1 0). Once around, a leg touches the previ· ous turn, thus measuring the d ista nce between rounds. When the tem porary spiral is com pleted, the spider reverses direc· lion, rolls up the old and puts down new more n u merous a n d closer spaced spirals o f sticky s i l k ( 1 1 ) . T h e complete spiral path back to the h u b is retraced ( 1 2) . Most rebuild t h e radii a n d spi· rals each day a r nig ht; some re move the web d u r i n g the day. A central decoration characteristic of the species may be added, or a silken retreat i n roll ed u p leaves may b e m a d e at o n e side of the web, with a d irect l i ne to the hub that transmits vibrations of insects ca u g ht i n the web. There are many variations from this simpl ified d escri ption .

OR B-WEAVERS

ARANEU S is the largest genus of spiders, with over 1 ,500 species found in mast porta af the world. Many species make a retreat In a rolled-up leaf near the web. Web vibrations are transmitted to the retreat from a signal l ine at足 tached to the hub.

A. nordmanni 2 15 mm (0.6") N . Hemisphere

ORB-WEAVERS

SHAMROCK SPIDEl A. trffollv•

wldetpread In N. A.; m•aGciWJ. � may be white

ORB-WEAVERS

Araneus cavaticus

eastern U .S. and Canada

FURROW SPIDER Nucten ea cornufa

widespread in N. Hem isphere; on build ings

Nuctenea patagiata '? 1 1 mm (0.511)

N. Hemisphere

LAniCE SPIDER

A raneus th addeus '? 8 mm (0.3") eastern U.S .

ORB-WEAVERS

Araneus pegnia east, U.S., Mexico

<i1 6 mm (0. 2 11 )

ORB-WEAVERS

ďż˝ 8 mm (0.3 " )

merianae Eu rope

OR B-WEAVERS

Zygiella x-notata � 8 mm (0.311} Europe,

U .S. Pacific

Atlantic coasts

Zygiella africa � 8 mm (0.3"} Europe, Brit. Col umbia and eastern Ca nada to New England

ORB-WEAVERS

Mangora gibberosa

eastern U .S., Canada; grass

OR B-WEAVERS

CYCLOSA hang in the hub, hid den by d ebris i n a vertical line. Egg sac is i n center of web. The spider's a bdomen extends be yond spinnerets.

�

C. conica

� 5 mm (0.2") N. A., Eu rope; wood lands

� C. turbinata

J!..

� 3

N.A.

(0. 1 11)

ORB-WEAVERS

Cyrtophora citricola

<;? 15 mm (0.6") Med iterra nean; hos web l i ke Mecynogea

Aculepeira sp.

<;? 20 mm (0.8 " ) western U .S., mountain meadows; A . ceropegia ďż˝ widespread in Eurasia

ORB-WEAVERS

<IIIII

NEPHILA, found in southern U .S. and i n the tropics, ma kes o huge web, 1 m (39 11 ) or more i n d iom路 eter. The strong webs, matted and twisted, are used by South Sea Islanders for va rious kinds of bags and fish nets. Young Neph路 ita make a com plete web; adu lts build only the bottom portion, leavin g the top irreg ular. Neph颅 i/a has conspicuous tufts of hair on the legs. Females vary in size. 65

GASTERACANTHA, tropical spid

ers with a hard a bdomen a rmed with spi nes, hang i n middle of web, adorned by w hite tufts and often h i g h in a tree.

BOLAS SPI DER Mastophora bisaccata

southeastern U .S. Bolas spiders make n o web, but attract male moths by imitating the p heromone (perfume) of female moths.

--"""'!!!::!!! �!�;?

M ICRATHENA incl udes spid ers with a spiny, hard, g l ossy abdo足 men. Several N .A. species are found i n woods and g a rdens; many occu r in American tropics.

WHITE MICRATHENA M . mitrata

9 5 m m (0.2 11 ) eastern U .S.; woods

STAR-BELL I E D SPIDER Acanthepeira sle//ala

9 1 2 mm (0.5 11 ) eastern U .S.; low shrubs

BLACK AND YELLOW ARGIOPE A . aurantia � 25 mm ( 1 " )

U .S., Canada; gardens ARGIOPES are la rge, conspicuous

spiders that hang head down in center of web. The web usually has crossed zigzag bands, and the young spiders may construct more zigzags than the adults. Some species are easily recog· n ized by their color and pattern. Species of A rg iope are fou n d in tropics and temperate regions-

A. trifasciata � 2 5 mm ( 1 " )

cosmopolitan; fields

A . bruennichi � 25 mm ( 1 " ) 68

E u rope

A. a rgenrara

New World tropics

' und erside

ORB-WEAVERS

RAY SPI DER Theridiosoma gemmosum

� 3 m m (0. 1 11) Eurasia, N .A. shaded woods

RAY S P I D E R S (Theridiosomatidae) form a sma l l fam i l y of tiny spiders related to the other Orb-weavers { p . 52) . The sma l l web, only 1 0 em (4") in d i ameter, lacks a hub but has severa l rad i i tied together near the center. The spider holds up the web i n the center by a tight thread so that it forms a n umbre l l a . If a fly gets caught, the thread i s released , causing the web to spring back and entangle the catch . The spider has a g lobular a bdomen ; the sternum i s short and square beh i n d . The egg sac is suspended on a sta l k . One species is widesprea d ; a bout 1 20 a re known from the tropics.

)� � face

Tetragnatha sp.

ORB-WEAVERS

T E T R A G N AT H I D S

(Tetrag nathidae) make a n orb-web, usua l l y at a n a n g l e between vertica l and horizonta l . The orb usua l l y has 1 2 to 20 rad i i and w i d e l y s p a c e d s p i ra l s . T h e s p i d e r hangs i n the center o r c l i ngs to a sta l k somewhere near the web . U n l i ke other O r b -weave r s , h oweve r, the fema l e Tetragnathids, except L e ucauge, lack a n epigynum {p. 9) . Fewer than two dozen species of Tetrag nathids occur north of Mexico.

THICKJAWED SPIDER Pachygnatha sp.

� 6 mm (0.2 11) eastern U .S.

SPIDERS (Leucauge) are common i n wooded o reas of eastern U .S. The spiders hang in center of horizontal orb. About 1 70 species are tropical. ORCHARD

LONG-JAWED

SP I DERS (Pachy. gnafha) are fou n d under debris or i n dense vegetation near wa ter. Young make small orb-web on g rou nd; a d u lts make no web. THICK-JAWED

ORB-WEAVERS,

Tefragnafha, at rest may cling l engthwise along a twig or g rass blade, hold i n g on with the short third pair of legs. The long pairs of legs are extended. More than a dozen species a re common in meadows near water throughout N.A. and E u rope. There are more than 250 species i n all pa rts of the world.

Tetragnatha pal/escens

eastern U .S. to Ce ntral America ORB-WEAVERS

spinnerets

spin nerets

face

Agelenopsis

Tegenaria

F U N N E L WEAV E R S (Agelenidae) are seen most easily in late summer when morning dew makes their webs in lawns conspicuous. The spider hides at the narrow end of a funnel that spreads out across the grass . On feeling the vibration of an insect crossing the web, the spider dashes out, bites the insect, ďż˝ nd carries it back to the funnel . As the spider grows, it uses its long posterior spinnerets to add new layers to the flat web. Like other web spiders, Funnel Weavers have three leg claws and poor vision. In fall, the female deposits a discÂ shaped egg sac in a crevice, then dies - often while still

600 species in the family, 300 are found in N . A . and 95 in Europe. Despite

clinging to the egg sac . Of some about

lack of a cribellum, the Agelenidae are related to the Amaurobiidae (p. 1 1 1 ) . Agelenopsis web in grass

GRASS SPIDERS (Age/e n opsis and Agele na ) make funnel webs in g rass or low bushes. There are several similar species of Age/en apsis in N .A., each living in a slig htly d ifferent habitat. Age/a na labyrinthica is common in Europe.

GRASS SPIDER Agelenopsis

N .A.

�

.....

� 1 5 mm (0.611)

sp.

C. terresrris

9 20 mm (0.811)

9 1 3 mm (0.511) Europe; leaf l itter

' COELOTES comm u n icates with her young by making special move ments when feed ing, summoning them to share the food. As a warning signal, she stamps her fourth leg, and the young scurry into hiding. The mother can dis tin g u ish between her young and potential prey by the d ifferences i n vibrations in the web and by touch. The young eat the mother when she d ies in autu m n . Most observations have bee n made on the European C. ferrestris.

FUNNEL WEAVERS

T. rlomestica

<;! 1 2 mm (0.511) cosmopolitan

. ..

T. saeva

E u rope; buildi ngs, gardens

' � 1 6 mm (0 . 6 11)

C. merlicinalis

� 1 2 mm (0.511) N .A.

( Te g en a ria ) build funnel webs in dark, moist rooms or cellars. Some species live i n q uarries or woods. Most of the 90 species described are Eu ropean; fewer are native to N.A. CORAS webs were once used for d ressing wou nds. Webs of both Coros and Tegenaria have a cu rved open end; in Great Britain the web is cal led a ·cobweb. Found i n cel_!p rs or fou ndations of buildings and u n d e r loose bark, stones, and logs.

C I CU RINA a re smal l funnel weav路 ers that l ive in leaf litter and u nder stones. N umerous species in N .A., some in Europe. CRYPHOECA are found in similar

habitats. Species occur in north路 ern U.S., Canada, Europe.

iS 6 mm (0.211)

Cryphoeca sp. northern N .A., _..._-----. Eu rope; leaf l itter, debris

H A H N I IDS (Ha h n iidae), shown below, have spinnerets arra n ged in a si n g l e transverse row. They a re often con颅 sidered a subfamily of the F u n nel Weavers, but they never m a ke a fu n ne l . Fewer than 1 00 species are known, 1 9 north of Mexico. Al l a re s m a l l , less t h a n 4 m m (0.2"), and their del icate webs, com mon ly made in m oss or in footprints of a n i m a l s i n moist soi l or snow, can b e seen only when laden with moisture. The spider l ives beneath g ra i n s of soi l at the edge of the web.

EUROPEA N WATER SPIDER is found in ponds, shal low la kes and q u iet streams of Eu rope and Asia. It b u ilds a bel l-shaped web among pla nts u nder water a n d fills the bell w i t h air bubbles car足 ried a n its body. Occasionally the spider replen ishes the air. To do this, the spider comes to the s u r足 face, touches it with its first legs, then turns around and projects its abdomen thro ugh the surface film. A q u ick motion with the hind legs replenishes the air carried

F U N N E L WEAVERS

around the abdomen a n d under the cepholothorax. The spider swims upside down. It remains d ry because of the air clinging to its body. Aquatic sow bugs and i nsects are captured and eaten under the bell, and the young a re raised there. U n like m ost spiders, the males are larger than the females. The bite of these spiders is painful to m a n . Sometimes water spiders a re p laced in a sepa rate family, Argyronetidae.

LYN X S PI D E R S (Oxyopidae) a re hunting spiders that chase t rr prey over vegetation or lie in wa it and leap out. All are active during daytime and have good visio n . Thei r six large eyes form a hexago n , and there are two smaller eyes below. Lynx Spiders use their s i l k as a drag l i ne for j u m p i ng and for anchoring the egg sac to vegetation, not for catching prey. The female g uards the egg sac . Lynx Spiders have three claws on the leg tips. The legs have many long , strong seta e . The abdomen is poi nted behind . Most of the 400 species a re tropica l ; fewer than 20 species a re found north of Mexico and sti l l fewer i n E u rope .

GREEN LYNX Peucetia viridans

ďż˝ 16 mm (0.6 11 ) southern U .S.

face

carapace Do/omedes

face Pisaura

N U RS E RY W E B S PI D E RS (Pisauridae) attract attention because of their large size. They may sit quietly for hours, legs spread out on vegetation or boat docks, or they may hunt actively i n vegetation. Their vision is good . Nursery Web Spiders resemble the related Wolf Spiders (p. 82) but differ i n habits . Their eight eyes are about equa l in size, and they have three tarsal claws . The female carries her huge egg sac in her jaws. When hatching time is near, she ties leaves together with silk and suspends her egg sac among them . She then sits on guard nearby. The young spiders leave the nursery after about a week . Many Nursery Web Spiders can run over the surface of water. If chased , they dive and stay submerged for some time. Of about 500 species throughout the world, about 1 5 occur north of Mexico; fewer occur i n Europe.

Pisaura mirabilis ďż˝ 1 5 m m (0.6")

ca rrying egg sac

P ISAU R I NA in N.A. and Pisa ura af Europe are common spiders. They have no permanent homes but h u nt in g rass, mead ows, and moist, open woods. When cou rt ing, the male Pisa ura presents the femal e with a fly. If she accepts, he will mate while she feeds. Pisaura mirabilis � 1 5 mm (0.6")

�

Europe

Pisaurina m ira

n u rsery in m i l kweed

N U RSERY WEB S P I D E RS

N U RSERY WEB S P I DERS

WOLF S P I D E R S

(Lycosidae) are among the most common spiders . They run on the ground or over stones, and some may venture up plants. At rest they stay under stones . Some dig short tunnels, others deep burrows . Many hunt during the day or, i n warm climates, at night. They have good vision and a highly developed sense of touch . Ma les wave their large, often hairy pedipa l ps in a rhythmic pattern as they approach potentia l mates . The female attaches her large egg sac to her spinnerets. If the egg sac is removed , the spider searches, and upon finding the sac attaches it to her spinnerets again. She may substitute bits of cork, paper, or sna il shells for the egg sac if lost. As the young spiderlings emerge, they climb onto their mother, who carries them on her back, brushi ng them away from her eyes. If any fa l l off, they climb up the mother's legs aga i n . Wolf Spiders make nice pets . In captivity they must be provided with water. About 2 , 000 to 3, 000 species of Wolf Spiders are known . Perhaps more than 200 occur north of Mexico . Some species are widespread over the Northern Hemisphere; others are very loca l . They make up a large proportion of the spider population i n the Aďż˝ctic and on high mountains. Wolf Spiders have four sma l l eyes i n a row below four la rger eyes, and three tarsa l claws .

Lycosa

ÂŽ w face

Pardosa

carapace

WOLF SPIDERS

coropace

face

LYCOSAS are la rge, common Wolf Spiders. There a re n u mer ous species. Most are nocturnal and can be collected with a light at n ig ht. Some hide under ob jects; others dig burrows, from which they ca n be l ured by in serting a straw or a piece of grass. Largest in the U n ited States is the Carolina Wolf Spider (L. ca,ro/inensis), which may be 25-35 mm ( 1 - 1 .511) long. I ncl uded i n the genus is the Eu ropean Tara ntu la (L. tarentu/a) of Med iterra nean countries. Its b ite was alleged to be poisonous, its victims cu red only by d a ncing the tarantella. The bites may .have been con fused with those of Widows (p. 42) , as the Eu ropea n Tarantula is not now considered poisonous.

carrying young southeastern U.S.

L. tarentula

� 25 m m ( 1 11 ) , !;? (not il l us.) browner and larger southern Eu rope

WOL F SPIDERS

Pirata piraticus N. Hemisphere � 7 mm (0.311), with egg sac;

P IRATE WOLF S P I DER (Pirata) in·

elude a few species of small spiders found i n ma rshes, ot edges of ponds or running on water surface. All have a V• shaped dark mark on the cara pace. PARDOSAS of more than 1 00 species are found in N.A. and E u rope. Many occur i n the Arctic and in the mou ntains. All a re small, active su n-loving spiders that build no permanent retreat. They confine the i r hunting to a particular a rea, however. They use their silk only to make an egg sac, which the female carries attached to her spinnerets. As in other Wolf Spider g enera, the species are d ifficult to d istinguish.

Pardosa pauxilla Florida

Pardosa groenlandica ,... Greenland to Alaska, high N.A. mts. 84

WOLF SPIDERS

ARCTOSAS are not as common as other wolf spiders, but the species are widespread through out the Northern Hem isphere. Their color may match the back ground on which they run. BURROWING

WOLF

SPIDERS

(Geolycosa) dig in sand, as deep as 1 m (39") straight down. They d ig with their chel icerae, and the sa nd grains are stuck together with silk and thrown out of the hole. The d ifferent colors of sa nd from the various levels may form concentric rings of varied colors around the hole. The spider spends most of its time i n the burrow; at night it is close to the surface. In fair weather the egg sac is brought up and sunned.

Arctosa sanctarosae

� 1 2 mm (0.511) U.S. Gulf Coast; sand

Burrowing Wolf Spider G e oly c o sa missouriensis

A eastern U .S.; sand

� •0a a0• '-._

w face

spinnerets

GNAPHOSIDS

(Gna phosidae) are usua l l y u n iform ly black, a few brown , some with markings . The long abdo men is s l ig htly flattened , and the front spinnerets a re cylin drical and sepa rated . The legs have only two claws (p. 13) . A l l a re nocturnal hunters and i n daytime a re found under stones or loose bark, often i n a s i l ken sac . The egg sac may be a shiny p i n k or white papery d i sc attached tightly to the underside of a stone; in some species it is a white sac gua rded by the female . Most Gnaphosidae have posterior med i a n eyes ova l at an angle (see a bove) and the endites ( p . 9) concave and s l i g htly constricted in their midd l e . Many of the 2 , 000 species of Gnaphosids a re found i n temperate reg i ons, proba bly 250 species i n N . A . and fewer i n Europe . Gnaphasa muscorum N. H emisphere

Zelotes subterraneus N . Hemisphere

'i? 9 mm (0.4" )

Drassocles lapiclosus

'i> 14 mm (0.611) Europe

GNAPHOSIDS

C/ubiono·o 0 '

I• I

spinnerets

SAC S P I D E R S (Ciubionidae) resemble Gna phosids but with less flattened a bdomen, l onger legs, and with c l osely spaced , conica l , front spinnerets . Many a re l i g htly col ored . They m a ke a resting tube i n a ro l l ed leaf or u nder bark or stones . More than 200 of a bout 1 , 500 species occu r i n N . A . Anyphaenidae are s i m i l a r, but with s l its of respi ratory tubes opening midway on the u nderside of the abdome n . Ma i n l y neotropica l , this fa m i l y has 36 species north of Mexico. photo Potzsch

Clubiona abbotii

� 5 m m (0.2 11 ) N.A.

ANT MIMICS are abundant i n t h e genera Micorio and Coslion eiro. They often l ive with the a nts they m i m ic, but the adva n tage of m i micry to the spider is not understood. The a bdomen may be constricted or covered with sca les; the gait is a ntli ke, and the fo rst legs are held like antennae. Micaria, mainly a north tem perate gen us, prefers dry a reas. Costianeira, mainly of New World tropics, hos a g rooved thorax and usually is l a rger and more brig htly colored than Micorio. Mica rio is now often considered a Gnaphosid .

Chelracanlhlum mlldel juv. 1 0 mm (0.4") Medi terra n ea n ; N.A. in b u i l d i n gs. First leg longer than l a st; many species poisonous Phrurotimpus borealis

northeastern N.A. litter

SAC SPIDERS

SENOCU LIDS

Senocu/id cara pace

Prodidomid carapace

....

�� face

(Senoculidae) in clude o n ly a bout two dozen species i n the American tropics. They have three claws and a re related to N ursery Web Spiders (p. 78) but dif fer in a rra ngement of eyes. Senoc u lids h unt on plants. The female guards her egg sac. PRODIDOMIDS (Prodidomidae) in clude 60 species with two claws. Related to Gnaphosids (p. 86) but differ in eye a rra ngement a n d i n having long, spread chelicerae. They a re found u n der stones in dry a reas in southern N. A. and in southern Europe. HOMALONYCHIDS

Homalonychid cara pace ------0 0

0 ()

oo oo

face 90

(Homa lonychi dae) a re found o n ly in Mexico and i n southwestern U.S. The legs of these spiders have two claws, may be h e ld straight.

WA N D E R I N G S P I D E R S (Cten idae) include a bout 550 spe足 cies of 5 -40 mm (0. 3- 1. 5") subtropical and tropica l spiders with two or three l eg c l aws . Eye a rrangement is d i a g nosti c . These spiders sometimes travel as stowaways i n bananas . lora ( p . 14) h u nts during the day on ground l i ke a wolf spider; others l ive on foliage.

G I A N T C RA B S P I D E R S

{Spa rassidae) are mostly tropica l spiders that hold the i r two-clawed legs cra b l i k e . larger than Crab Spiders (p. 94), they have teeth o n the i r jaws . About 850 species. H UNTSMAN S P I DER (Heteropoda venatoria), found around the world in tropica l regions, is welÂ comed in houses because it eats cockroaches. The spiders hide in crevices d u ring day and came out in evening. The fema les carry their egg sacs with the jaws. They

H u ntsman Spider, or Banana Spider Heteropoda venatoria

are found i n the southern U .S. and are commonly im ported with bananas. A similar h u ntsman, Olios, occurs i n the southwestern states and i n southern Europe. The front middle eyes of Olios are as large or larger than the lateral eyes.

wďż˝ W face

PLATO R I D C RA B S P I D E R S ( P iatoridae) of a bout a dozen species occur i n Asia and i n tropica l America . They are characterized by flatness, long middle spinnerets, widely spaced front spi nnerets, and two leg c laws .

�w LJ face

cara pace

- - - · · · -., . .· · · · · ·, ·� '

' '\'

,� , ' I

\ \'1 \\\\

,,, J ,

:t'! f

spinnerets

S E LE N O P I D C RAB S P I D E R S

(Selenopidae) i n c l ude 200 species of l a rge tropica l spiders eas i l y recogn i zed by their flatness and by their eye a rrangement-six i n a single row. Like other crab spiders, they have two leg c laws . Common i n houses a n d u nder bark or rocks; if d i sturbed , they dash sideways i nto crevices .

carapace face -

ill

�u -· · u ··. m

. .

·�·

M1sumena

carapace

car0 pace

C RAB S P I D E R S

Philoclramus

{Thomisidae, Phi lodromidae) hold their legs cra b l i ke, out at the sides, and can wa l k forwa rd , backwa rd , or sideways . The l a rgest a re tropica l species 1 2-20 m m (0. 5-0. 8") i n body length . Ma ny have horns or ornaments on the head or abdomen, and some m i m i c bird dropp i n g s . Ma les are smaller than females and have much longer leg s . Crab Spiders wa it i n ambush for passing i nsects; some hold their front legs outstretched i n rea d i ness. T h e i r v i s i o n f o r movements i s good . T h e i r j aws a re sma l l , and after prey is bitten, it is held a bove the spider and sucked dry. Those that sit on flowers a pparently have a toxin potent to bees, flies, and other i nsects much l a rger than themselves . They do not use silk to capture prey, but i n courtsh i p , the male may wra p his prospective mate loosely i n s i l k . Fema les of most species guard the egg sac but die before the eggs hatc h . Of a bout 2 , 000 species, more than 200 occur i n N . A . , fewer i n E u rope . FLOWER SPI DERS (Misumena, Misumenops) sit on flowers, and

can change color slowly.

Misumena vatia

� 10 mm (0.4 " ) N. Hemisphere biting bee

Stephanopis sp. � 6 m m (0.2") Chile

M . asperatus

� 5 mm (0.2 11) N .A.; vegetation

CRAB SPIDERS

X. cristatus <;? 7 mm (0.3 11 ) E u rope

X. emertoni � 5 mm (0.2 11 ) N.A.

XYSTICUS of more thon 230 spe· cies occur i n all parts of the world, mainly i n the Northern Hemisphere. Most are found under bark ar on the ground. D u l l brownish, they resemble their backg round. Males may look q u ite different from females. CORIARACH N E has several spe· cies occurring i n N.A. Extreme flatness adapts them to hiding in narrow crevices i n bark.

Tmarus angulatus

<;? 7 mm (0.3 11 ) N.A.

C RAB S P I DERS

Tibe/lus oblongus

ďż˝ 9 m m (0.4 " ) N. Hemisphere

PHI LODROM I D CRAB SPID ERS TIBELLUS, like long-jawed spiders ( p. 7 1 ), stretch along twigs and

g rasses. They usually are co lÂˇ lected in g rass by sweeping with a net. Males and females are similar in a ppearance# vegetation and bork i n N.A. and E u rope. A ca ptive T. formicin us had a food preference for moths.

THANATUS l ive on

P H I LODROMUS are attive

Spiders that climb on pla nts, or sometimes on in houses. Egg sacs are to leaves or bark. Many more than 1 70 species N.A. and in E u rope.

CRAB SPIDERS

face

ca rapace Sa!ticus

J UMPING S P I D E RS

(Salti cidae) a re among our most attractive spiders . Most have bright colors, often with i ridescent sca les. A large fa mily of more tha n 5 , 000 spe足 cies, J um p i ng Spiders a re most abundant in the tropics, but a bout 300 species occur north of Mexico and many in E urope . All a re sma l l , most less than 1 5 m m (0. 7") long . Jumping Spiders are active during the day and l i ke sunshine. They wa lk with an i rreg u l a r g a i t and leap on thei r prey, sometimes j umping many times their own length . Most of the jumping power is suppl ied by the fourth pa i r of legs, though they are only slightly mod ified for j u m p i ng . Before j u m p i n g , the spider secures a silk thread on which it can c l i m b back in case it m i sses its mark . At night or when it is coo l , the spiders stay in l ittle cocoons or i n crevices . Jumping S piders' eyes are among the best i n i nverte足 b rate a n i ma l s . Two of the eight eyes a re large. Many species can recog n i ze prey or other spiders at a distance of 1 0-20 em (4-8"). They can a l so change the color of their eyes . When a male J umping Spider fi nds a fema l e , he stops, waves his brightly colored first legs, wags h i s a bdomen , and hops . If the fema le is of the same species, she s i g n a l s w i t h h e r leg s . T h e first legs ( a n d sometimes third) may be colorfu l and enlarged . After mati ng, the fema l e constructs a s i l k cocoon for her eggs and g uards i t . 98

J UMPING SPIDERS

ZEBRA SPI DER Salticus scenicus

N. Hemisphere; buildings

Pe/lenes viridipes �

� 5 mm (0.2 11 ) eastern U .S.

� 6 m m (0.2 11 )

J UMPI N G SPIDERS

«;? 1 2 mm (0.5" )

1 00

J UMPING SPIDERS

is common in N.A.; none in E u rope. Large, heavy足 bodied and conspicuous, th.ese spiders are found on vegetation, stones, and sometimes i nside houses. In captivity, they are active and have good appetites. One ca ptive Phidippus ate more than 40 fruit flies in succession. P H I D IPPUS

P. clarus

N .A.; common on pla nts

1 02

J UMPING SP IDERS

P. johnsoni

� d isplaying at Rocky Mts. and westwa rd; stones

P. regius

!i? 1 8 m m (0.7'1 ) southeastern U.S.

P. apacheanus

� 9 m m (0. .411) Rocky Mts.

13 m m (0.511) J U MP I N G S P I D ERS

1 03

Synemosyna formica

<;? 5 mm (0.2") eastern U .S.

Synemosyna americana <;? 6 mm (0.2") Centra l America J umping Spiders That Mimic Ants

carapace Panama because they eyes in fou r rows, a re _ _ __ _ ,J_ ___ _, primitive jumping spiders.

Lyssomanes,

1 05

C R I B E LLATE S P I D E RS have a cribe l l u m , a flattened sieve l i ke p late i n front of the spi nnerets. Through it the cala mistrum, a row of curved setae on the next to last segment of the fourth leg, pulls silk. The hackled threads produced are covered with fine wool that enta ng les the prey. Every struggling movement of the p rey only in creases the entanglement. It was thought that fa mil ies of cribellate spiders are a separate, disti nct g rou p. Now the opinion is that the pres ence of the cribel l u m is an a n cestra l condition and the structu re has been lost severa l times. For instance, the Oecobiidae (p. 1 1 5) are similar to the U rocteida e (p. 34) though sma l ler and owners of a cribe l l u m . The cribe l l u m is stil l a good cha racter f o r identification.

•

Hypochifus

calamistrum

�

cribel l u m

Uloborus

electron microscope picture of cribellate silk V. Friedrich

HYPOC HILIDS

(Hypochil idae) are found in isolated re足 gions of Am erica, China, and Tasmania. Fewer than ten species are i ncluded in the fami ly. Some species resem b l e t h e Myga lomorphs (p. 20) i n jaw attachment and in hav足 ing two pairs of lungs with lung covers. U nder a ledge, Hypochilus builds its lampshade-shape web, covered with hackled threads; the spider hangs inside against the ledge. F lies may be caught on the outside of the web and p u lled throug h or they may be trapped under the web canopy. CRIBELLATES

1 07

cribellum

cara pace

F I LI STAT I D S ( F i l i statidae) of fewer than 50 species a re common i n southern E u rope and other warm parts of the worl d , a dozen in the U . S . The cribe l l u m may be difficult to see , but the shape of the carapace is d iagnostic . By day they hide i n a tubu lar retreat i n a crevice of a wa l l . As i n A riadna { p . 2 7 ) , s i l k strands rad iate from t h e mouth of the tube . Ma les have much longer legs than females. Fema les lack a n epigynum .

sp. (j? 1 8 m m (0.711) Arizona

Filistala

1 08

CRIBELLATES

ERES IDS ( Eresidae) of a bout 1 00 species a re found i n Eurasia a n d Africa, n o n e in t h e Americas. large a n d hairy, t h e y resemble Myga lomorphs (p. 20). Eresids live under a stone at the end of a si lken tube from which a web extends beyond the stone between p !r.mt stems. T h e web resem bles t h a t o f a Funnel Weaver (p. 7 2 ) b u t is n ot as clean a n d new looki ng. Some have a cover over tube. Ma les may be brightly colored. Some species are colonia l .

Eresus

carapace

.. Eresus niger ..... E u rasia, northern Africa

CRIBELLATES

1 09

Dictyna

D I CTYN I DS ( Dictyn idae) of a bout 500 sma l l ( l ess than 5 mm, 0 . 2") spe足 cies, worldwide i n d istribution , form the largest fa m i l y of cribel late spi足 ders ( p . 1 06). Common i n the U . S . a n d E u r o p e , t h e y s u p e r fi c i a l l y resemble Cobweb Weavers ( p . 36). The i rreg u l a r webs are at tips of p l a nts, under leaves, or i n crevices . Related Psechridae (not shown) of southeastern Asia and N ew Zea land have a tuft under the t h i rd c law.

AMA U R O B I I DS

(Amaurobi idae) a re much l a rger than the Dictynids and a re s i m i l a r to the Funnel Weavers (p. 72) . They are found under logs or stones, where they make a loose web with coarse hack l i n g . There are 300350 species; the fam i l y is worldwide i n d i stributi o n . Many N . A . a nd E u ro pea n species a re very com mon, but only the easily seen cribe l l u m dis tingui shes them from the Funnel Weavers.

Amaurobius

Titanoeca americana

� 6 mm (0.2 )

eastern U .S. Can ada

C R IBELLATES

111

ďż˝ 0

0 0

face

ACA N T H O C T E N I D S

(Aca n t h o c te n i d a e ) rese m b l e t h e Wa ndering S piders ( p . 9 1 ) b u t have a cribe l l u m . They have two leg c l aws. Their hackled webs are fou nd near their h i d i n g p laces under l oose bar k . About 25 species are known from the American tropics. Z O R O PS I D S

(Zoropsidae) have two or three l eg c l aws; most cribel lates have three . They differ from Gnaphosids ( p . 86) by the cri bel l u m and by scapulae under the last two leg seg ments . Two dozen species occur around the Medi Â terranea n , i n Mexico, a n d i n Centra l America .

OGRE-FA C ED SP IDERS (Dinopidae) usually have two enormous posterior median eyes; the remaining six eyes are small. During daytime they hide in shrubs, and at night, with a few parallel hackled threads, the spider makes a rectangular web supported by silk lines, which it holds with its front legs. When an insect approaches, the web is spread and thrown. Cosmotropical in distribu足 tion, about 50 species occur in the American tropics, one in southeastern United States. Menneus, of Australia, has small p osterior median eyes.

OGRE-FACE D SPIDER Dinopis spinosa

<;? 20 mm (O.B") southeastern U .S.

U LO B O R I D S ( U ioboridae) have a cribe l l u m but make orb颅 webs, though the spiders are not similar i n a ppea rance to Orb-weavers ( p . 52). U l oborids lack poison g l ands. About 200 species occur in a l l parts of the world . F ifteen species a re found i n N . A . , fewer i n E u rope, but they a re most abundant i n the tropics .

ULOBORUS orb is often horizon路 tal . I n stead of sticky thread, as in the web of Orb路weavers, the spiral is made of hackled threads. Species of U/oborus are fou n d in the U .S. a nd i n E u rope; some species are social. Related genera are found in the tropics.

g/omosus

'i? 7 mm (0.3") N.A.

1 14

CRIBELLATES

HYPTIOTES web is triangular. The spider attaches itself to a twig by silk from its spinnerets and holds the web with its fi rst legs. The spider itself bridges a gap in the threads. When a n insect gets caug ht, the spider pulls the web taut, then lets it go slack a g a i n . T h i s f u rther enta n g l es t h e prey.

The web is m a d e by constructin g a bridge, a vertical l i ne, and two more radii. Scaffo l d i ng threads run out from the center, a n d hackled threads a re put down separately i n each sector. H. cavatus is found in eastern U.S., southern Canada. H. paradoxus is commonest E u ropean species.

TRIANGLE SPIDER H. cavatus ďż˝ 4 mm (0.211)

N.A.

(Oecobiidae) have a cribellum a n d are tiny; otherwise t h e y rese m b l e t h e Old World U rocteids ( p . 34). Oecobiids m a k e sma l l flat w e b s over crevices in walls a n d on various leaves. They feed on ants, and som e are socia l . They have a large, hairy anal tubercle. Most species a re tropical and subÂ tropical; a few inhabit houses in the North. O EC O B I I DS

C R I BELLATES

115

SPIDER

RE LATIVES

A n u m ber of g roups (orders) are bel i eved to share a com mon a ncestry with spiders (pp. 6-7) . Al l have jaws (chel i cerae), ped i pa l ps (sometimes pi ncer l i ke), and fou r pa i rs of wa lking legs. They differ in adaptations of the appen dages . I n some, the a bdomen is seg mented and joi ned broa d l y to cepha lothorax. WH I PS C O R P I O N S (order U ropyg i ; a bout 85 species) occur i n some parts of southern U . S . , but are most abun dant i n Centra l and South America , Asi a , a nd the East I nd ies . They have no sting but can pinch. All a re nocturna l ; they have poor vision, but a re sensitive t o vibrations. or Vinego roons (Thelyphonidae), aim a vinegar scented mist from a glond at the base of the tail when d istu rbed . The spray contains acetic acid and a solvent that attacks the exoskeleton of i nsects. Other tropical species smell of formic

V I NEGARONES,

V I N EGARONE

acid or of chlori ne. Vinegarones bu rrow in sand or under logs and carry their prey i nto the b urrow. Female carries 20-35 eggs in a membranous sac u nder her abdo men. The young ride on the mother u ntil their fi rst molt, then become independent. larg est whipscorpion known; males and females a re similar i n a ppearance 8 em (3 " )

1 16

Trithyreus pentapeltis

6 mm (0.2 11 ) ... southern California

S C H I Z OM I DS (order Schizom ida , sometimes cal led Schi足 zopeltidia) o re sma l l , none more than 6 mm (0. 2") long . They lack eyes, a nd the short ta i l has only three segments . About 80 species live i n the tropics and subtropics under stones and i n leaf litter. TA I L L E S S W H I P S C O R P I O N S ,

or Whi pspiders (order Amblypyg i ) , have a wide head and thorax, t o w h i c h the abdomen i s attached by a sta l k . The first pa i r of legs is long and w h i p l i k e . Amblypygids hide under bark or stones, and if the stone i s turned , scurry sideways to the other side . In the U . S . , they o re found i n the wa rm South , where they may come i nto houses . Others a re found i n tropica l America, Africa, and Asia . Female carries eggs a nd young for fou r to six days . About 70 species o re known i n two fa m i lies, C h a rontidae and Tara ntu lidae.

W I N DSCORPI O N S

(order Sol ifugae) are sometimes ca l led Sun Scorpions because most l ive i n deserts or d r y areas. From 1 t o 5 em (0 . 3-2") l o n g , most a re yel l owish or brown . They have enormous jaws, and their l eg l ike ped i pa l ps a re u sed w i t h t h e first pa i r o f l e g s as feelers. They wa l k on only six legs, as do Wh i pscorpions ( p . 1 1 6) and Ta i l less Whi pscorpions ( p . 1 1 7), and run swiftly-" l i ke the wind . " Sensing prey, they may stop sudden l y, then sta rt aga i n . Some can c l i m b trees . Windscorpions a re voracious feeders . With their large pi ncer l i ke jaws they can k i l l even sma l l vertebrates and may sometimes feed on sma l l l i zards. They can bite but do not have poison g lands. It i s believed that some use their eyes for hunti n g , but most use touch on ly. The mal let sha ped organs on the last pai r of legs are proba bly sen sory. At rest, Solifuges may burrow or sit under stones . Most a re nocturna l , but some a re active d u r i ng the day. Ma les are genera l l y sma ller and have longer l egs than the fema les. Fema les bury their eggs and may guard them . Adu l ts l ive less than a year. Windscorpions of the Old World belong to several fa m ilies. They are abundant i n Africa and the Near East; a bsent from Austra lia . Six species are found i n southern E u rope. A l most 1 20 species occur i n N . A . north of Mexico, 900 worldwide. They are found as fa r north as southwest ern Canada but are most abundant in Arizona and the Great Basin area . One species occurs in Florida, the only one known from eastern U . S . Windscorpions of N . A . belong t o two easily recogn i zed fa m i lies, but t h e species a re d ifficult to identify. I n the fa m i l y Ammotrechidae, the first pair of legs have no claws, and the front edge of the head is rounded or poi nted . In the fa m i l y Eremobatidae, the fi rst pair of legs have one or two claws, a n d the front edge of the head is stra ight. 1 18

W I N DSC O R P I O N S

Ammotrechella stimpsoni

mal let足 shaped organ

2 0 mm (0.8 11 ) Florida, West I n d ies

underside of wi ndscorpion Solpugidae, easte rn Africa

E. durangonus 2 8 mm ( 1 . 1 11 ) Texas to Cal ifornia, northern Mexico

E. pal/ipes 26 m m ( 1 11 ) N. Da kota to Arizona

D SCORPIO NS

1 19

PSE UDOSCORPIONS

(order Pseudoscorpiones) are com足 mon everywhere but are rarely seen because of their secretive habits. They are sma l l, most of them less than 5 mm (0.2") long. Almost 200 species are known from N.A. Most species l ive i n leaf litter, moss, manure, under loose bark, or under stones. Many can be col lected from l itter with a Tul lgren funnel (p. 1 8) . Pseudoscorpions c a n walk backwards as w e l l a s for足 ward. They do not have a long tai l and stinger as do scorpions, but most have poison g lands i n their pincers. The poison is used solely to capture sma l l insects, their prey. Pseudoscorpions are not large enough to bite. They have si l k glands opening on their jaws, and use silk to make chambers for overwintering, molting, or brooding. Many species lack eyes and, judg ing from the long hairs on the pincers, their main sense is touch. Pseudoscorpions sometimes atta ch themselves to flies or to beetles; they a re carried as hitchhikers, not as parasites. In courting behavior, the ma le waves his pincers, vi足 brates h is a bdomen, or taps his legs. The fem a l e responds and the two an ima ls, their pincers locked, pul l eac h other back and forth. Eventua lly the male deposits on the g round a sta lked capsu le containing spermatozoa. As the female is pul led over the capsule, she picks it up with the lips of an opening on the underside of her abdomen. The eggs, i n a little sac, stay attached to the fema le's ab足 d omen, and when the young hatch, they remain in the sac a n d feed on a mi lklike secretion from the mother's ovaries. Usua lly there are fewer than two dozen young, but there may be more than one brood a year. After leaving the egg sac, the young ride on the m other for a short time. It may be one to severa l years before they become adults; during this period, the young m o lt three times. 1 20

PSEU DOSCORP I O N S

Lamprochernes minor

3 mm (0. 1 ") ďż˝ a n d 'i1 in courtship

sp. 2 m m (0. 1 11 ) N .A.; suborder H eterosphyronida, tarsi of last 2 legs d ivided Apochthonius

Chitrella s p. 3 mm (0. 1 ") N.A.; suborder Di plosphyronida, all ta rsi d ivided

one of the largest, is found i n houses all over the world. Probably they feed mainly on clothes moths and carpet beetle la rvae, book-lice, and other sma l l insects a n d mites; they are reported to l i ke bedÂ bugs. In search of moisture they often become stranded in si n ks or bath tubs, u nable to climb out over the smooth surface. HOUSE PSEUDOSCORPION,

cancroides

4 mm (0.2") cosmopolitan; suborder Monosphyronida, none of the tarsi d ivided PSEUDOSCORPIONS

1 21

SCORPIO N S

(order Scorpiones) have pincers a n d a long tai l with a stinger at its tip . The pecti nes, a pair of comblike structures underneath the last legs, are sense organs of touch. Scorpions have two eyes i n the center of the head and usua l ly two to five a long the margin on each side. They do not see well, and depend o n touch, using the long setae on their pincers. When running, they hold their pincers outstretched. Ma les have broader pincers and longer tails than do fem a l es. Most scorpions live in warm, dry c l imates. But one species is found as far north as Alberta; in Europe, Eu scorpius germanus is fou nd to a ltitudes of 1 ,800 m (6,000 ft.) in the southern Alps; others are found near snow i n the southern Andes. Species are restricted t o sma l l a reas, and o n ly one is found world-wide in tropics. Scorpions feed at night on insects and spiders that are caught with the pincers and someti mes stung. Scorpions that remain under stones or bark during the day carry their tails to one side; burrowers hold their tails up. I n courtship the male holds the female by the pin cers or jaws a n d leads her back and forth. Eventua l l y he de posits a sta lked package of spermatozoa (a spermato phore) a n d p u l ls the fema le over it. She picks up part of the capsule wi h an org �n on her a bdomen. The young

--{ q'�� ' "" - �: �� -�:-� --�:-_-- � '\" -

sp _...,..,...,._ s rnum

,· -

.,.:._

D IPLOCENTRI DAE contains tropical scorpions from the West I nd ies a n d southweste r n N.A. The large Nebo is found in eastern Med iterra nean countries. The sides of the sternum a re parallel, a nd only one spur is present on the outside between the last leg segments. All have a tubercle underneath the tip af the sti nger.

Diplocentrus hasethi

5 em (2 11 ) Lesser Antil les 1 22

SCORPIONS

ride on the mother's back until they shed thei r skins for the first time, then become independent and l ive a solitary l i fe that may l ast severa l years . Scorpions sting i n self-defense . Most s tings a re not seri o u s , b u t da ngerous scorpions occur i n N o r t h Africa, S . A . , and Mexico. I n the U . S . , Centruro ides sculp turatus of A r i z o n a has poison t h a t affects t h e nerves, causi ng severe pa i n . Species of Centruro ides in Mexico have caused deaths . Scorpion antiveni n s a re ava i l a b l e . O f over 1 , 200 species known , 20 t o 30 o c c u r i n t h e U . S . Scorpions a re best collected a t night when they are active, with a black l i g ht, which makes them fl uorescent i n the da rkness . SCOR P I O N I DAE co ntains Old World a n d Australian scorpions. Some are gia nts. Only one, Opis· thocanth us, occurs in the West I n d ies a n d Central America. The last two leg seg ments have only one spur on the outside, as in Diplocentridae, but there is n o tubercle u nd e r t h e stinger.

sp. to 17 em (7 " ) Africa; rocky areas Pandinus

SCOR PIONS

1 23

Sothriurus banarie nsis

5.5 em (2.2 11 ) southern S.A. CHACTIDAE, represented here by Euscorpius, is a family world-wide

in d istribution. The sternum is al most square or wider than long. There may be either two spurs between the last two leg seg足 ments o r one-and if one, it is on the inside. They moy have two eyes on each side of the head or none. Superstitiona, a three足 striped scorpion about 4 em ( 1 .611) long, is found in south足 western U.S.

Euscorpius carpathicus

S cm (2 11 ) southern Europe, very common

BOTH R I U R I DAE contains mostly

South American scorpions, a few from Austra lia. The ste r n u m con足 sists of two tra nsverse plates, much wider than long, sometimes barely visible. VAEJOV I DAE sco rpions have a

b road sternum, like C hactids, but have th ree to five eyes on each side of the hea d . Some species occur in the Old World, a nd ..... many a re America n .

Northern Voejovis

Paruroctonus boreus

5 em (2") western U . S . t o Alberta

VAEJOVID SCORPIONS

SWOLLEN-STINGER A NUROCTONUS II .4JIII.... Anuroctonus p#taeodactylus

6 em (2.411) Uta h to California

MORDANT U ROCTONUS Uroctonus mordax

6 em (2.4 11) Oregon, Cal ifornia

STRI PED-TAI LED VAEJOVIS

V. spinigerus 5 to 8 em (2-3") southwestern U.S.

YELLOW VAEJOVIS V. flavus

4 em (1 .5") southwestern U.S.

GIANT HAIRY HADRURUS

SCORPIONS

1 25

BUTH I DAE,

underside of Buthus

EUROPEAN BUTHUS

with

600

species, has

some representatives o n oil conti nents except Antarctica; i t i s the l a rgest fam i l y of scor p i o n s . The sternum i s triangu lar, poi nted in front and often longer than it is wide. Many species have a tuberc le that i s located under the sti nger. The p in cers have a gracefu l , slen der hand . Some spec ies are poi sonous to man - Ti t y us in Braz i l , Androctonus i n North Africa , and · Centruroides i n Mex i c o .

B . occitanus

5 cm (2 11 ) southern Europe; s t ing painful

SPOTTED I SOMETRUS

�

1 26

lsometrus macu/atus

5-7

(2-2.7 11 )

cosm o tr o p ica l

l - .:..:·:-

�l��

HASETH'S CENTRU ROIDES

C. hasethi

5 em (2 11 ) � with young Lesser Antilles

H ENTZ'S CENTRUROIDES

C. h e n tzi

Florida; under bark

SCULPTURED CENTRUROI DES Ce n truroide s seu/pturatus

6-7 em (2.4-2.8 11 ) Arizona; poisonous

SCORPIONS

1 27

HARVESTM E N

(order Opiliones) a re commo n l y ca l l ed Daddy-long-legs, but many have short l eg s . They hold thei r short, round bodies near the g round . If caught by a leg , the leg may break off. The head, thorax, a n d a bdo足 men a re joined broad ly, and i n the middle of the head are two eyes, usua lly one on each side of a high turret . In many species, spines, tubercles, or bristles arm the hea d ; scent g lands open a long the edge of the carapace. Ma les a re sma ller than fema les and have longer legs. U n l i ke other a rachnids, Ha rvestmen do not court before mati ng . With a long , stout ovi positor, the fema l e deposits her eggs i n the g round i n the fa l l ; the you ng hatch i n the fol l owing spring . Most species l ive less than a year or two . Harvest足 men feed mainly on l iving i nsects, sometimes on dead a n i m a l s or plant j uices. There a re 200 species in N . A . , 4 , 500 to 5 , 000 worldwide. M I T E H A R V E STM E N

(suborder Cyphophtha l m i ) are all less than 3 m m (0. 1 ") long . Eyes, if present, are far apart and indisti nct, and the scent g l a nds are on cones . U n l ike most m ites, they have a segmented abdome n . Mite Har足 vestmen inhabit hum id l e a f l itter. P robably not rare, but seldom collected . There are five families. F ive or six species a re recorded for the U . S . Captives l ive four to six yea rs .

Siro duricorius

Austria, northern Yugoslavia; forest litter

LANIATORES (suborder) include about 2,000 species, mostly tropica l, but with a few representatives in south足 ern and western U.S. and in Europe. laniatores have the basa l seg ments (coxae) of the fi rst three pairs of legs touching at the midline. The sma l l fam i l y Oncopodidae (not i l l u strated), found only i n southeastern Asia, has the body (except for the last segm ent) covered by a hard plate. The Assami idae (not illustrated) carry their slender pedipa l pi crossed over. Included are 300 species from southeastern Asia, Australia, and Africa . Stygnomma spinilera

4 mm (0.2 11 ) Florida

hove two claws, visible with hig h-powered hand lens or m iscroscope, on the fourth leg. There are 20 to 30 species in N.A.

PHALANGODIDAE

TRIAENONYCHIDAE have a sin足 g l e claw (with th ree teeth) on the fourth leg. Members of this family are found i n Madagascar, Austra lia and the Americas, sev足 eral north of Mexico. HARVESTMEN

1 29

COSM E T I DA E a r e a l l A m e r i c a n species a n d most a r e tropica l . A l l have a sma l l median t h i r d c l a w a t the t i p a/ the fourth l e g . T h e s m a l l pa lpi have segments fl attened and keeled .

GONYLEPTIDAE is a family of a bout 600 species in the Ameri足 can tropics. It incl udes the har足 vestmen with the l a rg est f>ody. All have a sma l l median third claw at the tip of the fourth leg. The large palpi are not flattened. Sadocus po/yacanthus

1 1 mm (0.5 11 ) Chile

1 30

HARVESTMEN

PAL PATORE S (suborder) conta ins most tem perate zone Eurasian and N.A. harvestmen. Of a tota l of a bout 900 species, 1 50 occur north of Mexico. Basa l leg segments (coxae) sepa rated by the breastplate (sternum). Tragulus tricarinatus 1 0 m m ( 0. 4 11 ) E u rope; u nd e r sto nes

TROG U LI DA E are s l ow and noctur足 na l , with the eye tubercle projecting i n front and overhanging the jaws. The European Trogulus, commonly encrusted with s o i l particles, i s a predator on sna i l s . T. tricarinafus has been esta b l i shed in upstate N . Y.

u n d e rsi d e

NEMASTOMATIDAE

have very short jaws and n o cl aws o n their ped i p a l p i . The fo rst a n d fourth basal leg seg m ents (coxae) have marginal rows of spines. The eyes are o n a tuberc l e . About five spe足 cies occ u r north of Mexico, 50 i n the world .

C ros

c u s d a sycnemus

1 . 5 m m (0. 06") eastern Canada, U . S .

CERATOLASMATIDAE have microscopic sculpturing on

u n d erside

Nemastoma sp. 4 mm (0. 2") E u rope, eastern Canada H A RVESTM E N

131

.......

palp

ISCHYROPSALIDI DAE usually have huge jaws, lack c l aws on the pedi palps, a n d have shari legs. About 30 species in fam i ly, 8 north of Mex ico.

P H A L A N G I I DA E ( Da d d y - l ong legs) are widespread i n E urope and temperate N . A . Each ped i p a l p has a sma l l claw at its t i p , and in all species, the legs are long and stilt l i k e . Of about 800 species, 1 00 to 1 50 occur north of Mexico. Caddi dae are a related f a m i l y with large

1 32

HARVESTMEN ,

underside

northeastern U.S., Canada HARVESTMEN

1 33

MITES

(order Aca ri ) a re fou nd throughout the world and i n a l l types of habitats . They surpass a l l other spider l i ke a n i m a l s i n numbers . Many a re parasites on p l a nts or a n i m a l s , a n d some transmit d i sease . Others are freeliving predators . Some a re aquatic-mostly i n fresh water, a few in the ocea n . Among the pa rasites are some extraord inari ly speci a l i zed species, adapted to live only i n b i rd feathers or nostr i l s , under bat wings, i n monkey lungs, bee tra cheae, a nd s i m i larly restricted habitats . Most mites a re very sma l l , but they can be collected i n abundance from soil or litter b y u s i n g a Tu l l g ren funnel ( p . 1 8) . A mite's body is fused into o n e piece, with no sepa ra tion between head and abdomen . In parasites, the mouth pa rts may be spec i a l i zed as sharp, piercing stylets . Ad u l t m ites have fou r pa irs o f l e g s , b u t l a rva l mites have only three . Some worm l i ke, microscopic g a l l mites have fewer legs. More than 30, 000 species are na med , proba b l y a fraction of the tota l . Many have become pests s i nce the widespread use of pesticides . M E S O S T I GMAT I D M I T E S

(suborder Mesostig mata) have either a s i m p l e claw on the ped i pa l ps, or none . Many have plates on the back and underside. Some are free-living p redators and can be co l l ected with a Tu l l g ren fu nnel . Others are parasites and l ive i n the fur of m a m m a l s , on b i rds, or on insects . Spinturnix sp.

(0.04")

Jt.

laela pt i d Mite Laelaps vacua 1 34

M ITES

1 .5 m m (0.06 " ) on insects

TROMBIDI ID MITES

(suborder Trombidiformes) i n c l ude many plant and animal parasites and some p redators. Water Mites (p. 1 36) a re usua l ly placed in this group.

C H IGGER

Trombicula sp.

a d u lt, 3 m m (0. 1 11 ) C H I GGERS, or Ha rvestmites (Trom bicul idae), form a family of about 700 species. Ad ults a re predators on insects or insect eggs; larva l stages are parasites. Fewer than 50 species attac k huma ns, biti ng where clothing is tight a n d c a u s i n g severe itching. After feed ing, they fall off. Some peo ple a re i m m u n e . In the Orient, chigger m ites carry scrub typh us. I n the U.S. they are most a b u n dant in t h e South.

or Red Spiders (Tetra nychidae), 0.3-0.8 mm (.0 1 • 03 11 ), are serious pests o n vari ous crops. They often invade buildings i n fall . All have silk glands opening near mouth a n d m a k e a loose w e b among leaves. S P I DER M ITES,

(Trombid iidae) a re of l ittle economic im porta nce • There are several thousand spe cies. Larvae a re parasites on in sects; l a rge a d u lts (to -4 mm, 0.2 11 ), usually velvety red, eat insect eggs. V ELVET MITES

WATER M ITES (Hydrachnel lae), a group of several families, are related to trombidiid m ites (p. 1 35). Many are colorful-red, g reen or yellow. Some crawl on stones, others swim. The lang hairs on their legs help them to paddle, but their bodies are streamlined and nearly smooth.

Most Water Mites a re predators, but some are parasitic on clams or insects. Those that pa rasitize d ragonflies attach themselves to nymphs ready to leave the water, then to become airborne on the newly molted ad ult. They d rop off into the water, possibly when the insect lays its eggs.

SARCOPTID M I TES (suborder Sarcoptiformes) includes the Sca bies or Ma nge Mites, the Cheese Mites found in many stored prod ucts and causing the a l lergy "grocer's itch," and the Ori batid Mites.

M ITES, also called Beetle Mites or Moss Mites, in路 elude several fam i l ies of free路 living Sarcoptid Mites. With their hard, shiny shells they may re路 semble tiny dark brown or black beetles. Some can tuck their legs under h i nged "wings,'' forming a l ittle ball. Most are len than 1 mm long. I n some, the shed skins collect on the back, making a high ornament. Most Oribatid Mites live i n soil or litter, but those found on decaying wood are seen most often . They are of economic im porta nce in break颅 down of l itter and formation of humus. Some feed on eggs and transmit ORIBATID

Phthiracarus sp.

1 m m (0.04 11 )

walking

MITES

1 37

well fed ďż˝ WOOD TICK, Dermacentor, sp. 2 em (0.8 11 )

T I C KS (suborder lxodides) are the la rgest of the mites, as much as 3 em ( 1 .2") long after feeding. A l l are exÂ ternal pa rasites of repti les, birds, or mamma ls. Most d rop off their h ost after feeding. They molt and then wait on the tips of leaves, forelegs outstretched, ready to attach to any a n i m a l brush ing post. Young ticks, which hove o n ly th ree pairs of legs, mov attock sma l ler host animals than the adu lts. The bite of some ticks may ca use m i ld para lysis to m a n ; others tra nsmit disease. Ticks attach themselves to the host only with their mouthparts, and feed o n b lood . I n removing a tick, toke core not to leave mouthpa rts beh i n d . About 300 species o f ticks occur a round th e world. Soft ticks (Argasidae) hove a leathery integ ume nt; they hove no head plate, and the head is on the underside. Hard ticks ( Ixodidae) hove a hard p late a bove the head and the head is directed forward . 4 mm (0.2 11 )

SOFT TICKS BLUE BUG

A rgas p e rsicus pa rasite af birds and bats; often pests af pau ltry in warm, d ry parts of world Ornithodoros sp.

parasites of mamma ls, incl uding mon; may tra nsmit relapsing fever i n western U .S. 1 38

MITES

5 mm (0.2 11 )

LO N E STAR TICK

Amblyomma americanum

4 mm (0.2 11 ) southcentral U.S.; o n large mammals, man

Dermacentor andersoni

western N .A., Rocky Mts.; aHacks large mammals, man; may tra nsmit d iseases. D. variabilis in eastern N .A. BROW N DOG TICK

Rhipicephalus sanguineus

4 mm (0.2 11 ) found in houses, rarely bites man; cosmopolitan

B oophilus sp.

4 m m (0.2 11 ) stays on host throug hout life

HARD T I C KS M ITES

1 39

Eulcoenenia

2 m m (0. 1 11) without tail Texas

sp.

M I C R OW H I PS C O R P I O N S

(order P a l p i g ra d i ) a re a g i l e arachnids l ess t h e n 2 mm (0. 1 ") long . They l ive under stones, going deeper i nto the soi l if it gets too d ry. Of the 50 to 60 species known , 3 occur in the U . S . , in Texas a nd Ca liforn i a ; other species are found i n the Med iterra nean reg i o n .

R I C I N U LE I DS (order Ricinulei) resemble ticks. They move about slowly in l i tter and leaf mold of h u m i d , wa rm areas, and may feed on termites . They a re 1 0- 1 5 mm (0.4-0. 6") l o n g , with a heavy cutic l e . I n front of the head is a unique h i nged hood covering the jaws . Young Ricin u leids have only six leg s . As recently as 1 929 fewer than 40 speci mens of Ricinu Cryptocellus sp. leids were known to 4 m m (0.211) have been fou n d , a l l Central ond S.A. from Africa a n d S . A . Now they are known to occu r widely in the American tropics and i n Mexican caves . O n l y o n e species, found i n Texas , i s known from the U . S . The fema l e car ries the sing l e egg be tween the bent ped i pa l ps and the hood . About 35 species a re known . 1 40

MYRIAPODS

Myriapods a re the classes of arthropods i n which the body i s made u p of n umerous s i m i l a r segments . PA U R OPODA, a class c l osely related to m i l l i pedes, a re soft-bod ied , less than 2 m m (0 . l ") long , with 1 2 segments and usua l l y nine pai rs of legs . The more than 500 descri bed species are found i n the tropics and tem pera te reg ions, where they l ive i n decaying logs, forest l itter, h u m u s , and under stones. They probably feed on fungi and decaying a n i ma l s . Most a re sensitive to light and to drying . SYM P HYLA,

a sma l l class of 1 60 known species closely related to centipedes and m i l l i pedes, a re found i n the tropics and temperate regions. Symphyla are 2-8 m m (0. 1 0 . 3") long , with 1 5-22 back plates, 1 2 pairs of wa l k i n g legs, and a pair o f spinnerets . They live i n m o i s t , rotting wood or i n soil and l itter. U n l i ke centi pedes and m i l l i pedes, they m ove a l l legs on one side together. They feed on decaying vegetation but may attack living p l a nts and become garden pests . GARDEN CENTIPEDE

Scutigerel/a immaculata 8 mm (0.3 " )

E u rope, N.A., Hawaii; pest i n gardens and g reenhouses

141

C E N T I P E D E S (class C h i l opoda) have one pa ir of legs on each seg ment . The fastest a re the ones with fewest legs, the Scutigeromorphs and Lithobi omorphs . Si nce the plates on their back hook together, they can hold the body stra ight in running . The Scolopendromorphs and ma ny足 legged Geoph i lomorphs a re slow and may move with snake l i ke motions; all their dorsa l trunk plates a re a l i ke a nd move freely. About 2 , 500 species of centi pedes a re known . The orders of centi pedes are descri bed and i l l us足 trated on pp . 1 43- 1 45 . Like insects a n d m i l l i pedes but u n l i ke spiders, centi pedes have a pair of antennae. Most are nocturna l . In daytime they h ide i n litter, under l oose bark, stones, leaves, and debri s . Some dig i nto the soi l . They avoid extremely wet or dry n iches . Centi pedes a re predators, feed ing mostly on other arthropod s . All have poison g l a nds open ing through their jaws , and the bite of even a sma l l centi pede, if it succeeds i n breaking the ski n , can produce pa i n . Scolopendra, the la rgest, can g ive a very pa i nfu l bite, but usua l l y is not da ngerous. Some centi pedes lack eyes and a re b l i n d ; others do not see wel l . In experi ments i n which g l a ss beads were d i pped i n "fly j uice, " some centi足 pedes tried to bite the beads . They wou ld not touch g lass beads d i pped i n water, however, and so i t is assumed that centi pedes find thei r prey by smell and perhaps by touc h . Some centi pedes c a n produce si l k , w h i c h is used o n l y during mating and when captu r i ng prey. W h e n a male fi nds a female, they touch antennae, and he fo l l ows her. The male makes a sma l l web i n wh i c h h e deposits a package of sperm . The sperm is then picked u p by the fem a l e . The male's b u i l d i ng of a web has been observed o n l y among the Geophi l omorphs, Lithobiomorphs, and Sco l o pendromorphs . 1 42

C E N T I PEDES

com pound eye antenna maxilla 2

face

Scutigera co/eoptrata

3 em ( 1 .2 11 ) southern Europe a n d southern U .S.; o utdoors. Farther north in buildings

S C U T I G E ROMORPHA

is a n order of mostly tropica l centipedes. About 1 30 species have been descri bed ; a l l belong t o the fa mily Scutigeridae. U n l i ke other cen足 tipedes, they h ave a round head and l a rg e compound eyes. They have 1 5 pairs of long legs. A fem a l e of Scu足 tigera prod uced 35 eggs over a period of days. The eggs are not guarded. Young centipedes a re born with only seven pairs of legs, but the n u m ber i ncreases with every molt. In ca ptivity, the common Scutigera found throughout the U.S. may live more than a year. It is the o n ly centipede common i n houses, where it runs rapidly a long wa lls and floors as it h unts for fl ies and other insects. It is surprisi n g ly agi le. I n summer they live outside, or i n warm climates they live outside the year around. C E N T I PE D E S

1 43

u nderside of

LITHOBIOMORPHA, or Stone Centipedes, are a l l less than 4.5 em ( 1 .7") long. Adu lts have 1 8 body seg ments, 1 5 pairs of legs a n d 20 to 50 or more segments in the a ntennae. As in Scutigeromorphs, the young have fewer legs. When disturbed, they move the last pairs of legs rapid ly, th rowing droplets of sticky material at the poten足 tia l predator a n d slowi ng it i n the tangling mass. About 1 , 1 00 species have been described i n this order. G EOP H I LOMORP HA,

or Soi l Centipedes, a re slender, eyeless centipedes that have 31 to 1 77 pairs of legs and a nten nae with 1 4 segments. The longest a re 1 6- 1 7 em (6"), but most a re less than 5 em (2"). The n u m ber of pairs of legs is a lways odd, usua lly varia ble withi n the species, and each leg can be moved independently. Soi l Centipedes penetrate as deep as 40 to 70 em ( 1 6-28") into soi l, feeding on i nsect larvae a n d worms. If dis足 turbed, they coi l up and eject from pores on their u nder足 side a secretion that seems to repel potential p redators. A n u m ber of species can give off phosphorescent mate足 ria l. Fema les guard their eggs. About 1 ,000 species.

SCOLOPENDROMORPHA have 2 1 or 23 pairs of legs a n d 1 7 to 30 seg ments in their a nten nae. World-wide and mainly tropica l, the order i n cludes the la rgest cen足 tipedes. Many a re a n attractive blue-green, o live-green, or yellow. To pick one u p, it is best to use two hands a n d forceps a s they ca n inflict a painfu l bite a n d can a l so pinch with their last pair of legs. They have been o b足 served feeding on toads and lizards. These large cen足 tipedes dig burrows and a lso make cham bers i n which they rest. The female often coi ls around her eggs or young a n d may periodica l ly lick the eggs, presumably to clea n them. About 550 species described i n two fa m足 i l ies: Scolopendridae and the blind C ryptopidae.

Sco/opendra 1 4 em (5.5 " )

sp.

g uarding young

S. heros (611) 1 5 cm

Arizona

C E N T I PE D E S

1 45

M I LLI P E D E S (class D i p l opoda) are "thousa nd leggers , " differi ng from the "hundred leggers" or centi pedes ( p . 1 42) i n having two p a i r s o f l e g s on most body rings (wh ich a re two fused seg ments) . They have one pair of a ntennae. Some m i l l i pedes a re cylindrica l , ada pted for burrowing; others a re fla t . Some resemble wood l ice ( p . 1 52 ) . Some are soft-bod ied, very sma l l , and covered with saw-toothed hairs (p. 1 47) . Mi l l i pedes a re found under stones, i n moist soil and leaf litter. They avoid l i g ht and feed on va rious p l a nt materia l s, espec i a l l y soft decomposing plant tissues . Most m i l l i pedes have pores, usua l l y a long the sides of their body rings, from which they d i scharge strong-smel l i ng secretions that may be repel lent and poisonous to other a n i m a l s . Some large tropica l m i l l i pedes squ i rt their secretion s . N everthe足 less, m i l l i pedes are prey of birds, toads , and other a n i ma l s . I n most m i l l i pede groups, the legs on t h e seventh r i n g of the m a l e a re modified as copulatory organs (gonopods). The shape of these organs i s i m portant in identifying spe足 cies. The female l ays her eggs i n the soi l ; some species construct egg capsules and gua rd them . J ust-hatched m i l 足 l ipedes have few r i n g s and three pai rs o f legs, t h e n u m ber increasing with each molt. Some species l ive only one year, others to seven . More tha n 1 0 , 000 species are known , about 600 north of Mex ico . egg c h a m ber of Atopetholus

broken open, with young

1 46

i n tact

Polyxenus lagurus

(0. 1 11)

Europe, sim i l a r species i n N . A.

P S E LA P H O G N A T H A

is a subclass of soft m i l l ipedes, a l l less than 4 m m (0.2") long, with 1 1 to 1 3 ri ngs. They have many rows and bund les of barbed hairs. Ma les do not have legs modified for copu lation . Found i n most pa rts of the world, there are a bout 60 species of two fa m i lies; Po lyxenidae has 5 species in N.A. They feed on a lgae and live under loose bark and in litter. C H I LOG N AT HA,

the subc lass i n c l udi n g a l l other m i l l i 足 pedes, have hardened body r i n g s and ma les h a v e legs modified for copu lation. There are a n u m ber of orders.

G LOME R I D A , Pi l l Mi l l i pedes, are short and wide, re足 sem bling wood lice (p. 1 52), but have m ore tha n seven pairs of legs. The ma le's last pair of legs a re modified to hold the female when mati n g. G lomerids ca n coil into a ba l l when d isturbed, some tropica l species approaching the size of golf b"l ls. Species fou nd i n southern states and in Ca lifornia are never more than 8 mm (0.3") long. Common i n Eu rope, where some species reach a length of 2 em (0.8").

PLATYDESMIDA

are flat with a tiny head and from 30 to 1 92 body rings. I n males, the 9th and 1 Oth pairs of legs are m odified as copulatory organs (gonopods) . The usua l color is pink. The rough dorsal sur face has a na rrow l ongitudinal g roove. About a dozen species occur in North America north of Mexico. POLYZONIIDA are very similar to Platy desmida but are smooth and lack the dorsa l groove. The usua l color is cream. About 15 species occur north of Mexico. The orders Platydesmida and Polyzoniida, with sma l l heads, belong i n the super· · order Colobognatha.

CALLIPO DIDA,

with u p to 89 rings, have a pa i r of tiny spinnerets o n the last body r i ng . Most a re cyl i n d r i ca l , with latera l r idges a n d k n o b s . I n m a l e s , t h e second pa i r o f legs o n the 7th r i ng a r e modified a s g o n o p od s . Most produce strong-sme l l i ng white · secret i o n s from sti n k g la n d s . About 2 0 species are k n own n o r t h of Mex i c o , o n e widespread i n weste r n E u rope and many i n easte r n Med i terranea n . S o m e a r e fast- r u n n i n g scavengers a n d predators.

1 48

M I L L I PEDES

POLY D E S M I DA

is an o rder i n which most spec ies have 20 rings that usua l l y bear prominent kee l s w h i c h g ive them a flat l o o k i n g bac k . A l l l a c k eyes; the fi rst pa i r of l e g s o n t h e 7 t h r i n g a re g o n o p od s . Many a re brightly colored ; a l most a l l have sti n k g l a n d s . Of 2700 species, about 250 occur n o r t h of Mex i c o , fewer i n E urope .

�

GREENHOUSE M I LL I P E D E

Oxidus gracilis 2.5 em ( 1 " )

cosmopolita n in g reenhouses and su btropics

�

Pseudopolydesmus serratus 3 em ( 1 .2 " )

eastern N .A.

Pachydesmus crassicutis

7 em (2 . 8") southeastern U.S.

Motyxia sp . ..... 4 cm ( 1 .5 " ) southern California; biol u m inescent

�

Sigmoria aberrans 4 cm ( 1 . 5") N. C a r o l i n a , V i r g i n i a

MILLIPEDES

1 49

J U LIDA

is one of four orders of cylindrica l millipedes that have both pairs of legs on the 7th ring of the male modified as copu latory organs (gonopods) . More than 1 00 species are found north of Mexico. The n umerous mem bers of the family Pa raiu lidae, or wi reworms, meas足 ure 1 5-90 mm (.7-3.5") long . Most a re smooth, with up to 74 body rings and the gonopods a re outside the body. I n ma les, the fi rst pair of legs a re g reatly enlarged . In the fa m i ly J u lidae, the gonopods a re i n a pouch, and the male's first pair of legs a re hook-sha ped. They are native to Europe a nd western Asia; introd uced to parks a nd gardens i n N .A. S P I ROSTREPTIDA

is a n order of large (to 28 em, or 1 1 ") cylindrica l millipedes fou nd mainly in the tropics. There is only one pair of gonopods, the anterior. In southwest足 ern U.S. a n d adjacent Mexico, mil lipedes of the genus O rtho p orus often cong regate in large n u m bers. Three species occur in states adjacent to Mexico. Orthoporus pontis

1 2 em (4.5") western Texas

1 50

M I L L I PE D E S

� Q � � �

ma uth pa rts

lamellae l in g ualis p ramentum stipes mentum c llum

Texas; caves

ead

CAMBA L I DA have no legs on the 4th ri ng; other m i l li pedes have one pair. Cambala (family C a m ba lidae) a re easi ly recog nized by the large cover (co l l u m ) of the fi rst body seg ment and by the prominent longitud i n a l ridges on the body of most species. Camba lida a re rare i n the Great Plains and sem i-d eserts. The l a rgest, to 60 m m (2.5"), occur in the Appalachian Mountains. S P I RO B O L I D A

have on ly one pair of legs on the 5th ri ng; other m i l li pedes have two pairs. The m a le's cop u la tory organs (gonopods) a re hidden i n a pouch. The four cylindrica l groups ca n a l so be sepa rated by the structure of the mouthparts on the underside of the head. About 35 species occur north of Mexico. Narceus p l aces each single egg, 1 m m long, in a capsu le of chewed leaf litter. The ca psule is passed posteriorly by the legs and i nto the rec tum where it is molded and then deposited in a pi le with many others.

mouthparts

.�

Narceus americanus (411) to 1 0 em southeastern U.S., n orth to Ohio a n d west to Texas; i n forest logs

head

M I L L I PEDES

1 51

LAND C R USTACEANS

Crustacea have two pairs of a ntennae. Though m ost a re aquatic (Crayfish, lobsters, Barnacles, Shrimps, Water Fleas), some have been successful on land. Beach F leas (Scuds) are found on moist ocea n beaches and in h umid tropics. Terrestria l Copepods a n d Ostracods are found in the Southern Hemisphere. WOODLICE

(order lsopoda) feed on h u m us a nd fungi. North of Mexico there are nearly 1 00 species. Eggs and young a re carried i n a brood pouch by the fema le. R O C K SLAYERS (ligiidae) a re am·

phibiaus an ocea n beaches. They feed on seaweed, m a i n l y at low tide. The small end of the long ante n n a e (secon d pair) has more than ten segme nts. P I LL BUGS (Armad i l l i d i id a e) have

an a rched bady and can rol l i nto a b a l l when d istu rbed. The two ta ils ( u ropods) are shorter than the last abdominal segment.

....

P I LL BUG

Armadi/lidium vulgare 1 .4 em (0.611) cosmopol ita n

�

(Trichoniscidae) a re found in wet spats. They are •mall, narrow-bod ied, and have only four to five seg m e n ts in sma l l end of the long a nte n n a e (second pair). Both the a nten nae a n d tails (uropods) a re tipped by a brush.

TRICHONISCIDS

1 52

LAN D CRUSTAC EAN S

SOW BUG is a nome used for species in two fam ilies. Those in the fa mily On iscidae, represented here by Oniscus, have three seg ments i n the small, segmented end of the long ante n nae (sec ond pair); most can not rol l i nto a bal l . Members of the family Porcellionidoe have two seg ments i n the small, segmented end of the long antennae (sec o n d pair).

Porcel/io scober 1 .4 em (0.611)

widespread, i n northern U.S.; tu bercles all over

�

Metoponorth us pruinosus

cosmopol ita n ; abdomen n arrow; end segment of long ante n n a e half length of previous one

.A.

Trachelipus rathkei 1 .2 em (0 . 511)

cosmopolitan, build ings; tubercles on head; in � , 3 rd seg ment from end of 7th leg has keel

�

Cylisticus convexus 1 2 mm (0.511 )

Eu rope, eastern U.S.; shiny, con rol l up LAN D CRUSTAC EANS

1 53

LAN D C RABS (Gecarcinidae), found only in the subtrop足 ics and tropics, a re la nd-dwelling crustaceans, but the females return to the ocean to reproduce. They dig tun足 nels 30-40 e m deep ( 1 2- 1 6"), 1 8 e m (7") i n diameter, and come out at night to feed . little ones climb wa l l s and trees. Land Hermit C rabs (Coenobitidae) can give a good pinch with their colorfu l claw if hand led carelessly. Most are scavengers. In the Southwest Pacifi c, the Coconut Crab (B irg us), growing to 45 e m ( 1 8") in length, feeds on fa llen coconuts, and can be destructive to crops. It is considered a delicacy itself.

LAND HERMIT CRAB

Coenobita clypeatus claw to 6 em (2.3 " ) d i a meter eastern Caribbean, southern Florida

LAN D C R A B

Gecarcinus latera/is to 9 em (3 .511) wide Florida Keys, Bermuda, West I ndies

1 54

MORE I N FO RMAT I O N

Baker, E . W. et a l . , A M a n u a l of Pa rasi t i c M i t e s , Nat'l Pest Control Assoc . , 1 956. A lot of information on m ites of economic i m portance . Barnes, R . D . , Inverte brate Z o o l o g y, Saunders, P h i ladel p h i a , 1 98 7 . A good textbook giving background on C rustacea , Myr i a pods and Arach足 nids. Bonnet, P. , B i b l i o g rap h i c Ara n e o r u m , Tou louse, 7 Vo l . , 1 945- 1 9 6 2 . An indispensable reference work listing all spider l iterature u p to 1 93 8 . I n larger l i braries only. C l oudsley-Thompson, J . l . , S p i d e rs, Scorpions, C e n t i pedes a n d M i tes, Pergamon Press, london, 1 96 8 . A very usefu l , accurate boo k . Foe l i x , R . F. , B i o l o g y o f S p i d e rs . Harvard U niversity Press, Cambridge, 1 98 2 . Spider b i o l ogy with emphasis on physiology and behavior. Gertsc h , W. J . , American S p i d e rs, 2nd ed. Van N ostra n d - R e i n h o l d , New Yor k , 1 978 . Natural h i story of American spiders. Grasse, P. , edit . , Tra i t e d e Zoo l o g i e , val . 6 , Masson & C i e , P a r i s , 1 94 9 . O n e o f t h e best s u m m a r i e s of b i ology, anatomy a n d systematics of spiders and a l l ied groups; i n Frenc h . J o n e s , D . T h e La rousse G u i d e to S p i d e rs , Larousse, N . Y. , 1 98 3 . P i ct u res of E uropean spiders. Kaestner, A . , adapt. lev i , H . W. and l . R . lev i , Inve rtebrate Z oology va l . 2 : A rt h ropod R e l a t i v e s , C h e l i cerata, a n d Myr i a p o d a . R. E . Krieger P u b l . Co . , Melbourne, F l , 1 980. A summary o f our knowledge of arachn i d s and myriapods; i n E n g l i sh . Kasto n , B . J . , How t o Know the S p i d ers, 3rd ed . W. C . Brown C o . , Dubuque, Iowa , 1 97 8 . Keys t o common spider genera . Kaston, B. J . , S p i d e rs of C o n n e c t i c u t , rev. e d . B u l l . Conn . Geo l . N a t . H i s ! . Surv. 7 0 , 1 98 1 . T h e most usefu l reference b o o k on spiders of eastern U . S . Krantz, G . W. , A M a n u a l o f Acaro l o g y. Oregon State U n iv. Bookstore, Corva l l i s , rev. e d . 1 97 8 . locket, G . H . and A . F. M i l l idge, B r i t i s h S p i d e rs , R a y Soc . , london, 1 95 1 - 1 95 3 . Speci a l i zed, separating spider spec ies of Great B r i ta i n . Roth , V. D . , S p i d e r G e n e ra o f North Ameri c a . P u b l i shed b y a uthor, Porta l , AZ, 1 98 6 . Key to fa m i l ies and genera fou n d in North America . Shuttlesworth , D. E . and S . N . Swa i n , The Story of S p i d ers, Garden C ity, New York, 1 959. An excellent c h i l d ren's boo k . Yag i n u m a , T. , S p i d ers of J a p a n i n C o l o r, Osaka, J a p a n , n e w ed . 1 98 6 . I n J a panese; well i l l u strated , the n a m e s o f spiders i n lat i n . 1 55

I NDEX Fema le, Abacion, 1 48

Argyronetidoe, 76

abdomen, spider, 8, 9 ,

Ariadna, 27, 1 08

Buthus, 1 26 , 1 27

Armad i l l i d i idae, 1 5 2

Caddidae, 1 3 2

Acaces ia, 6 1

Armad i l l i d i u m , 1 5 2

Caddo, 1 3 2

Acanthepe ira, 67

Arrenurus, 1 36

calamistrum, 1 06

Acanthoctenidae, 1 1 2

Arrowshaped

Acanthoctenus, 1 1 2

Micratheno, 67

C a l l i lepis, 87 C a l l i podidae, 1 48

Aca r i , 1 34 - 1 39

Arthropoda, 4 , 6

accessory claws, 1 3

Assomi idae, 1 29

Cambo l a , 1 5 1

Achoearaneo, 40, 50

Atopetholus, 1 46

Cambo l i d a , 1 5 1

Acrograph inotus, 1 30

Atrax, 1 6 , 24

Caponiidae, 26

Aculepeira, 64

Atypidae, 25

carapace, 8 , 9 , 1 6

Aelurillus, 1 00

Atypus, 25

Carolina Wolf Spider, 8 3

Age lena, 73

Aysha, 88

Castianeira, 89

Age lenidae, 72-76

Cal lobius, 1 1 1

Castor Bean Tick, 1 39

Agelenops is, 72, 73

ba llooning, 1 5

Cattle Tick, 1 39

Amaurob i i dae, 1 1 1

Banana Spider, 92

Cave Orb-weaver, 60

Amaurobius, 1 06 , 1 1 1

Banded Argiape, 68

Cave Spiders, 3 2 , 5 1

Amblyomma , 1 39

Barn Spider, 58

Centipedes. 1 42 - 1 45

Amblypyg i , 1 1 7

Barychelidae, 2 1

Centruroides, 1 2 3 , 1 26 - 1 27

American House

Basilica Spider, 64

cephalothorax, 8, 9, 1 6

Spider, 36

Bathyphantes, 49

Ceratice l u s , 45

Ammotrechella, 1 1 9

Beach Fleas, 1 52

Ceratolasmatidae, 1 3 1

Ammotrech idoe, 1 1 8

Beetle Mites, 1 37

Chactidae, 1 24

Amphipod a , 1 52

B i rd Spiders, 20, 2 1

Chorontidae, 1 1 7

anal tubercle, 9, 1 3 , 3 1

Birgus, 1 54

Androctonus, 1 26 Anelosimus, 38

Ma le

Black & Yel low

Argiope, 68

Cheese m ites, 1 3 7 Cheiracanthium, 1 6 , 89 cheli cera , 8 , 9 , 1 6

Anoples, 1 2

Black Widow, 1 7 , 36, 42

Chel icerata, 4 , 6

ant mimics, 89 Antrodiaetida, 23

Cheliler, 1 2 1 Chiggers, 1 35

Antrod iaetus, 23

Blue Bug, 1 38 Bolas Spider, 66 book lung, 9, 1 2 - 1 3

Anuroctonus, 1 25

Booph ilus, 1 39

C h i lopoda, 1 42- 1 45

Anyphaenidae, 88

Bothriocyrtum, 23

Chitrella, 1 2 1

Aphonopelma, 2 1

Bothriuridoe, 1 24

Chryssa, 38

Apochthonius, 1 2 1

Bothriurus, 5, 1 24

Arachnida, 4 Araneidae, 52-69

Bowl & Doily

Spider, 47

C h i lognatha, 1 47

Cicurina, 75 claws, 1 3 , 1 29 , 1 30 C l ubiona , 88-89

Araneus, 5 3 , 56-59

Brachycybe, 1 48

C l ubinonidae, 88-89

Aroniello, 59 Archaea, 5 1

Brown Centruroides, 1 27

Archaeidoe, 5 1

Brown Dog Tick, 1 39

Arctoso, 85 Arenoph ilus, 1 44

Brown Recluse Spider, 1 7

Cobweb Weavers, 36-43 , 5 1 74. 1 1 0 ' Coelotes, 7 3 Coenobita , 1 54

Argas, 1 38

Brown Spiders, 1 6 , 29

Argasidae, 1 38

Brown Widow, 43

collecting spiders, 1 8

Argiope, 1 4 , 5 3 , 68-69

bulb, 9

collum, 1 5 1

Argiopidae, 52-69

Burrowing Wolf

Argyrades, 39 Argyroneto, 76

1 56

Spiders, 85 Buthidae, 1 26- 1 2 7

Coenobitidae, 1 54 Coleosomo , 39

Colobagnatha, 1 48 colulus, 8, 9, 1 3 , 5 1 comb, 3 6 , 1 26

Combfooted Spiders, 36-43

Drapet i sca, 48 Drassodes, 87

Copepoda, 1 52

Dwarf Spiders, 44-45

Caras, 74

Dysdera, 27

Coriarachne, 96

Dysderidae, 27

Corytho lia, 1 04 Cosmetidae, 1 30

egg sac, 1 0 , 1 4

courtsh i p , spider, 1 0

embolus, 9

coxa, 8, 9, 1 6, 1 29,

endite, 8 , 9, 1 6 , 25

1 30, 1 3 1 Crab Spiders, 9 2 , 93 94-97 Cribellate Spiders, 1 06- 1 1 5 cribe l l u m , 3 , 8 , 1 06 Crosbycus, 1 3 1

Enoplognatha, 4 1 , 5 1 epigynum, 8, 9, 1 3 , 70 Episinus, 38 Eremobates, 1 1 9 Eremobatidae, 1 1 8 Eresidae, 1 09 Eresus, 1 09

Geca rcinidae, 1 54 Gecarc i n u s , 1 54 genital plate, 1 26 Geolycosa, 85 Geo p h i l o m o r p h o , 1 44 Giant Crab Spiders, 92 Giant H a i r y Hadrurus, 1 2 5 Glomerida, 1 47 Glomeris, 1 4 7 Gnaphosa, 86 Gnaphosidae, 86-87, 8 8 , 89, 90, 1 1 2 gnatho c h i l a r i u m , 1 5 1 Golden lynx Spider, 77 Golden S i l k Spider, 65

Cross Spider, 56

Erigo'le, 45

Crustaceans, 4, 5 ,

Eris, 1 0 1

gonopore, 8

1 52 - 5 4

Ero, 5 0

Gonyleptidoe, 1 30

Cryphoeca, 75

Euagrus, 24

gossamer, 1 5

Cryptopidae, 1 45

Eukoenenia, 1 40

Grass Spider, 73

Cryptocellus, 1 40

European

Greenhouse

Cryptothel e , 3 1

Buthus, 1 26

Ctenidae, 1 4 , 9 "t

House Spider, 74

Ctenizidae, 22 Cupiennus, 9 1

Tarantâ&#x20AC;˘ do, 83 Water Spider, 76

Cyclocosmi a , 2 2

E u r yopis, 3 9

Cyclase, 63

E uscorpius, 1 22 , 1 24

Cylisticus, 1 53

gonopods, 1 4 6

M i l l i pede, 1 49 Green lynx Spider, 77 Grocer 's Itch Mites, 1 37 growt h , spider, 1 1

Eusta l a , 62

Habrocest u m , 1 00

cymb i u m , 9

Evarcha, 99

hackledthread s , 1 06

Cyphophtha l m i , 1 28

eyes, 8, 1 6

Hadrob u n u s , 1 3 3 Had r u r u s , 1 2 5

Cyrtopho l i s , 2 1 Cyrtophora, 64 Daddy- long-legs, 1 28 , 1 32 - 1 3 3

fa ng, 1 6 , 1 43 , 1 44

Haemaphysa l i s , 1 3 9

Featherlegged Spider, 1 1 4

H a h n i a , 75

femur, 9

Hahniidae, 75

F i l istata , 1 1 , 1 08

Hairy Myga lomorphs,

Daddy- long-legs

F i l istatidae, 1 08

Spiders, 3 2 Dermacentor, 1 38 , 1 39

Fishing Spiders, 80-8 1

Hamata liwa, 77

F loricomus, 45

Hammock Spider, 46

Dictyna, 1 1 0

Florinda, 48

Haplodrassus, 87

Dictynidae, 1 1 0

F l ower Spiders, 94

Haplogyne Spiders,

digging rake, 2 3

Folding Door

8 , 26- 30 Hard Ticks, 1 3 8 , 1 3 9

Oiguetia, 30

Spider, 23

20-2 1

Diguetidae, 30

Frontinello, 47

Harvestmen, 1 2 8 - 1 3 3

Oinopidae, 1 1 3

Funnel Weavers, 72-76, 1 09 , 1 1 1

Ha rvest Mites, 1 35 Hasa r i u s , 1 04 Hoseth 's

Dinopsis, 1 1 3 Diplocentridoe, 1 22 Di plocentrus, 1 22

Funnelweb Mygalomorphs,

Centruroides, 1 2 7

Furrow Spider, 58

Helophora, 48 Hentz 's

Dipoena, 39

Garden Centipede, 1 4 1

Herpy l l u s , 87

Doliomalus, 93

Garden Spider, 56

Hersilia; 35

Dolomedes, 78, 80- 8 1

Gasteracantha, 66

Hersili idae, 35

draglines, 1 0, 1 5

Gea , 69

Heteropoda , 92

D iplopoda , 1 46 - 1 5 1 Di plosphyronida, 1 2 1 Dipluridae, 24

1 6, 24

Centruroides, 1 2 7

157 j

Heterosphyron i da , 1 2 1

l i g i i dae, 1 5 2

Micrommata, 92

Hexuro, 24

l i m nochares, 1 36

M icrowh i pscorpions,

Homolonychidae, 90

l i m u l us, 6

Homolonychus , 90

l i n y p h i a , 47

Micryphantinae, 44

House Pseudoscorpion ,

linyphiidae, 44-49

Migidoe, 22

linyphiinae, 46-49

M i l l i pedes, 1 46 - 1 5 1

l i p h i stiidoe, 5, 7

Mimetidae, 50

Huntsman Spider, 92

lithobiomorpho, 1 44

Mimetus, 50

Hydrachnellae , 1 36

lithobius, 1 44

Misumena, 94

Hypoc h i l idae, 1 07

lobed Argiape, 69

M i s u menops, 94, 95

Hypoc h i l u s , 1 06 , 1 07

lone Star T i c k , 1 3 9

Mite H a r vestm e n , 1 2 8

Hypse l i stes, 45

long-bodied C e l l a r

Mites, 1 34 - 1 39

Hyptiotes, 1 1 5

Spi der, 33

121 House Spider, 36, 74

long- jawed lcius, 1 0

Orb-weavers, 72 Loxosceles, 1 1 , 1 7 , 29

Monosphyron i d o , 1 2 1

loxoscelidae, 29 lung covers, 25

Mordant U rocto n u s , 1 25 Moss M i tes, 1 3 7

l sopoda , 1 5 2 - 1 5 3

lung s l i t s , 2 7 , 1 06

Motyx i a , 1 46, 1 49

lsoxyo, 67

lycoso, 1 6 , 8 2 , 8 3

Mygalomorph a , 20

Itch Mite, 1 3 7

lycosidae, 82-85

Myga lomorphs,

Ixodes, 1 39

lynx Spiders, 77

lxodides, 1 38- 1 3 9

lysso manes , 1 05

jaws, spi der, 8, 1 0 , 26 J u lida, 1 50

Myrmonyssus, 1 34

1 1 8- 1 1 9 Ma l m ignotte, 42

Norceus, 1 5 1

J u l i dae, 1 50

Monge Mites, 1 3 7

Nebo, 1 2 2

J u mping Spiders,

Mangoro, 62 Marbled Spider, 5 7

Nemastoma, 1 3 1 Nemostomatidoe, 1 3 1

Morpissa, 1 0 1

Nemes i o , 2 3

98- 1 05

�

labe l i n g , 1 9

Mosti goproctus , 1 1 6

:;(

labidognatha, 5, 26

Mastophora , 66

Neosc o n a , 59

labium, a. 9, 2 7

max i l l a , 1 43

Nephi I a , 65

labrum, 8 laelaps, 1 34

m a x i l l i ped, 1 43

Nesticidae, 5 1 Nest i c u s , 5 1

lamellae l i ng u a l is, 1 50 ,

Mec i c obot h r i i d a e , 24

Nops, 26

Mecynogea , 64

Northern Vejovis, 1 2 4

"' �

(!) z Ci2 ::> V>

.... � "

151 lamprochernes, 1 2 1

measurements used , 9

Neoonti steo , 75

Mecysmauche n i u s , 5 1

Northern Widow, 43

land Crabs, 1 54

Menemerus, 1 04

Nuctenea, 58

land Hermit Crabs, 1 54

Menneus, 1 1 3

Nursery Web

lan iatores, 1 29 larinia, 63

mentum, 1 50, 1 5 1 Mesostigmata Mites,

lathys, 1 1 0

20, 1 07, 1 09 Myriapoda , 5, 1 4 1 Myrmek i a p h i l a , 22

m a l let-sha ped organs,

.., 3!:

molting, 1 1 Monkey Spiders, 20- 2 1

lsometrus, 1 26

Ixodidae, 1 3 8- 1 3 9

�

Mitopus, 1 3 2

lschyropso l i s , 1 3 2

lschyropsalididae, 1 3 2

V> "' ,... w ..... w

1 40

1 34

Latrodectus, 1 7 , 42-43

Mesothel a e , 5

lattice Spider, 5 8

Meta , 1 5 , 60

Spiders, 7 8 - 8 1 , 90 Ochyrocera, 3 2 Ochyrocerotidae, 3 2 Odie l l u s , 1 32

leber t i a , 1 36

Meta cyrba, 1 00

Oeco b i i d a e , 34, 1 1 5

legs, spider, 9

Meta p h i d i ppus, 1 0 1

Oecob i u s , 1 1 5 Ogre-faced Spiders,

leiobu n u m , 1 33

metatarsus, 9, 1 06

lepthyphantes, 49

Metepeira, 64

leptoneta, 3 2

Metoponorthus, 1 5 3

Olios, 92

leptonetidae, 3 2

Micoria, 8 9

Oncopodidae, 1 2 9

leucouge, 70, 7 1

Micratheno, 67

Oniscidoe, 1 53

l i fe spa n , spider, 1 1

Microhexura , 24 Microli nyph i o , 47

Oniscus, 1 53 Onychophoro, 7

l i g i a , 1 52

1 58

113

Oonopidoe, 26

Pirate, 84

Salticus, 98, 99

Ophy i u l u s , 1 50

P i rate Spiders, 50

Sarcoptes, 1 3 7

Opil iones, 1 28 - 1 3 3

Pi rate Wolf

Opi sthacanthus , 1 23

Spiders, 84

Sarcoptiformes, 1 37 Scabies Mite, 1 3 7 scope, 9

orb webs, 54-55

P i s a u r a , 78-79 Pisauridae, 78 - 8 1

Orchard Spider, 7 1

P i s a u r i n a , 79

Schizomida, 1 1 7

Orchestina, 26

P i tyohyphantes, 46

Schizomus, 1 1 7

Oribatid Mites, 1 37

Platoridae, 93

Schizopeltid i a , 1 1 7

Oribatu l a , 1 3 7

P l atorid C r a b

sclerites, 5

Orb-weavers, 5 2 - 7 1 , 1 1 4

Ornithodoros, 1 38

Spiders, 93

Scaph i e l l a , 2 6

Sclerobunus, 1 29 Scolopendra,

Orodrassus, 87

P l atydes m i d a , 1 48

Orthognatha, 5 , 20

Plectreuridae, 30

Orthoporus, 1 50

P l ectreurys, 30

Scolopendridae, 1 45

Plexippus, 1 04

Scolopendromorph a ,

Ostea r i u s , 1 5 , 45

1 42 , 1 45

1 44

Ostracoda, 1 5 2

Poeci lochroa, 87

Oxidus, 1 49

poison glands, 8, 1 6

scapu l a , 1 3

Oxyopes, 77

poisonous spiders, 1 6- 1 7

Scorpiones, 1 2 2 - 1 2 7

Oxyopidae, 77

Polydesmida, 1 46 , 1 49

Scorpion idae, 1 2 3

Polyxen u s , 1 47

Scorpions, 1 2 2 - 1 2 7

Polyxenidae, 1 47

Scuds, 1 5 2

Polyzo n i i d o , 1 48

S c u l ptured

Pachydesmus, 1 49 Pachyg natha, 7 1 Palm Crab, 1 54 pa lp, 5 , 8, 9, 1 3 2 P a l potores, 1 30 Palpigrad i , 1 40 Palpimonidae, 3 1 Palpimonus, 3 1 Pandinus, 1 23 paracymbi u m , 9 Para i u lidoe, 1 50 Pordoso, 1 0, 8 2 , 8 4 pate l l a , 9 Pouropod o , 1 4 1 Peckho m i o , 1 05 pectines, 1 2 2 pedicel, 8 , 9 , 1 3 pedipolp, 5 , 8 , 9 , 1 3 2 Pellenes, 99 Peripatus , 6 Peucet io, 7 7 Pho longiidoe, 1 3 2 - 1 3 3 Phalong i u m , 1 3 3 Pholongod idae, 1 29 Phid ippus, 1 02 - 1 03 Phi lodrom idae, 94, 97 P h i l odrom u s , 94, 97 Pholcidae, 32 Pholcus, 3 2 , 3 3 Phoneutria, 1 6 , 9 1 Phthiracarus, 1 3 7

Polyzon i u m , 1 48

Centruroides, 1 2 7

Porce l l i o , 1 5 3

Scutigera, 1 43

Porce l l i onidae, 1 53

Scutigere l l o , 1 4 1

preserving spiders, 1 9

Scutigeridoe, 1 43

Prodidomidae, 90

Scutigeromorpha, 1 4 3

Proli nyph i a , 47

Scytodes, 2 8

promentum, 1 50- 1 5 1

Scytod idae, 2 8

Psechridoe, 1 1 0 Pselaphognotho, 1 47 Pseudopolydesmus, 1 49 Pseudoscorpiones, 1 20- 1 2 1 Pseudoscorpions, 1 20121 P s i l ochor u s , 3 3 P u r seweb Spiders, 25 Robbit T i c k , 1 39 Raft Spiders, 80 rake, 23 Roy Spiders, 5 2 , 70 rea ring spiders, 1 9 Red Spiders, 1 35

Sea Spiders, 6 Segestr i a , 2 7 Selenopidae, 93 Selenopid Crab Spiders, 93 Selenops, 93 Senoc u l i d a e , 9 0 Senoc u l u s , 90 setae, 36, 1 06 Shamrock Spider, 5 7 Sheetweb Weavers, 44-49 Short-bodied C e l l a r Spiders, 33 S i c a r i idae, 28

Red Widow, 4 3

S i c o r i u s , 1 1 , 28

R h i p i ceph a l u s , 1 39 R i c i n u l e i , 1 40

sifting, 1 8 S i g m o r i a , 1 49

R i c i n u l e i d s , 1 40

silk, 1 3 , 1 4, 1 5 , 22,

Rock Sloters, 1 5 2

5 3 , 78 silk glands, 1 3

Phruroti mpus, 89 Physocyc l u s , 3 2 , 33

Sobocon , 1 3 2

Pill Bugs, 1 5 2

Sac Spiders, 88-89

Pill M i l l ipedes, 1 4 7 P i moo, 49

Sodocus, 1 30 Solticidoe, 98- 1 05

S i lver Argiope, 53, 69 Siro, 1 28 Sitticus, 99

1 59

r S i x- eyed Crab Spiders, 28 Six - spotted F i s h i n g

Spider, 8 0

92, 1 1 6 - 1 1 7 Tara n t u l idae, 1 1 7

S o l i fugae, 1 1 8- 1 1 9

tars us, 9

Solpugidae, 1 1 9

Tegenaria, 72, 74

Sosippus, 85 Sow B u g , 1 5 3

Tetra g n a t h a , 70- 7 1 Tetra g n a th idae, 52, 70-71

Sporassidae, 92

Tetranych idoe, 1 3 5

spermatophore, 1 2 2 Spermophora, 3 2 , 33 Sphodros, 25

Spi ned Micrathena, 67 s p i n nef'ets, 8 , 9, 1 3 , 1 4 8 Spintharus, 38

Spi rostrepti da, 1 50

�

Spitting Spiders, 28 Spotted l sometrus, 1 2 6 Star- be l l i ed Spider, 67

T h o m i s idae, 94-97 T h o m i s u s, 95 T h w o i tesia, 39 tibia, 9

Stemonyphontes, 49

T i cks, 1 3 8 - 1 39

z Stepho n o p ; s , 95

stern u m , 9, 1 2 2 , 1 24 ,

< �

stipes, 1 50, 1 5 1

1 26, 1 3 1 •

Cl Stone Centipedes, 1 44

N z Storeno, 3 1 ii Strig o m i o , 1 44 :::J V) Stri ped Centruroides, <( 1 27 w

� Stripe·toi led Vejovis, 1 25

Styg nomma, 1 2 9 S u n Scorpions, 1 1 8 S u persti t i o n a , 1 24 Swo l len�stinger A n u roctonus, 1 2 5 Symphy l a , 1 4 1 Sym phytognathidae, 51 Synema, 95 Synemosyno, 1 05 Ta i l less Whipscorpions,

1 60

Therid u l a, 3 8 T h i ck-j awed Spiders, 7 1

T i be l l u s , 97

�

1 18

Theridion, 36, 37 Theridiosoma, 70

T h iod i n a , 1 0 1

V) Steatod a , 4 1 , 5 1 , 7 1 :I: Stegodyp h u s , 1 09 ....

Therid i idae, 36-43

T h erid iosomatidoe, 70

Spinturn i x , 1 34 Spi robo l i d a , 1 4 6, 1 5 1

U l o b o ridae,

5 2 , 1 06 , 1 1 4- \ 1 5 U l oborus, 1 06, 1 1 4 U m m id i a , 23 U rocteo, 34 U rocteidae, 34, 1 1 5 U roctonus, 1 24 u ropods , 1 5 2 U ropyg i , 1 1 6

Thanotus, 97 Theraphosidae, 20- :l l

spider relatives, 1 1 6

�

Tetronych us, 1 35 Thelyphon idae, 1 1 6

Spider Mites, 1 3 5

Tyrop hag us, 1 3 7

Tarantu l a , 20- 2 1 , 8 3 ,

Soil Centi pedes, 1 44

T u l l g re n f u n n e l , 1 8

Tapinopa, 49 Toracus, 1 3 2

Soft Ticks, 1 3 8

....

l a m a , 35

Tidarre n , 40 T i tanoeco, 1 1 1 Tityus, 1 26 Tmorus, 96 Trache l i p u s , 1 5 3 Trapdoor Spiders, 22 traps, 1 8 Trioenonych idae, 1 29 Tr;a n g l e Spider, 1 1 5 Trichon iscidae, 1 5 2 Trichoniscus, 1 5 2 Trithyreus, 1 1 7

Velvet Mites, 1 35 Vaejovidae, 1 24- 1 25 Vaejovis, 1 24, 1 25 Verrucose, 66 Vinegarones, 1 1 6 Vonones, 1 30 Wandering Spiders,

92, 1 1 2 Water M i tes, 1 35 , 1 36 Water S p iders, 76

webs, 1 3 , 1 5 , 52, 54 Web Wolf Spider, 85 Wh ipscorpions,

1 1 6, 1 1 8 W h ipspiders, 1 I 7 W h i te M i c ratheno, 67 W i dows, 1 6 , 1 7, 42-43,

51 W i n dscorpions, 1 1 8 - 1 1 9 W i reworms, 1 50 W o l f S p i ders, 78; 8 2 - 85 Wood l ice, 1 5 2 - 1 53 Wood T i c ks, 1 3 8 , 1 39 Xysti c u s , 96 Ye l l ow Veiovis, 1 25

tro c h a n ter, 9 Trochosa, 1 3 Trog u l idae, 1 3 1 Trog u l us, 1 3 1 Tro m b i c u l a , 1 3 5 Tro m b i c u l idae, 1 35 T ro m b idiformes, 1 3 5 - 1 36 Tro m b id i idae, 1 35 Tro m bid i u m , 1 3 5 True Spiders, 2 6

Zebra S p ider, 99 Zelotes, 86 Zi l l a , 6 1 Zodariidae, 3 1 Zara, 1 4, 91 Zorops idae, 1 1 2 Zoro psis, 1 1 2 Zygiella, 6 1 Zygoribatula, 1 37

B C D E F

SPIDERS and their kin A GOLDEN GUIDE® HERBERT W. LEVI, Ph . D. , is Alexander Agassiz profes

sor of zoology and curator of arachnology at the Museum of Comparative Zoology, Harvard University. He was born in Germany and received his education at the Uni versity of Connecticut and the University o f Wisconsi n .

D r . Levi has authored about 1 50 technical publications o n spiders a n d o n conservation . LORNA R. LEVI majored in biology at the University of

Wisconsin and has collaborated with her husband on several publications. NICHOLAS STREKALOVSKY studied art in England .

After working for the British Museum, he went to Egypt where he did illustrations of natural history and medical subj ects for the government. His first work in the United States was for the Agassiz Museum at Harvard Univer sity. In the Golden Guide Series he has illu strated Insect Pes ts and Spiders . HERBERT S. ZIM, Ph . D . , Sc . D . , an originator and former

editor of the Golden Guide Series, was also an author for many years . Author of some ninety books and editor of about as many, he is now Adjunct Professor at the Uni versity of Miami and Educational Consultant to the Amer ican Friends Service Commit.tee and other organizations. He works on educational, population, and e nvironmental problems . GOLDEN PRESS

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NEW YORK

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A GO� DEN -GUIDE®