PICTORIAL KEY TO RECOGNIZE FORENSICALLY RELEVANT INVERTEBRATE (FOR DUMMIES)
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COMPILED BY FRANCESCO PORCELLI & DANIELE CORNARA DISSPA - UNIVERSITÀ DEGLI STUDI DI BARI ALDO MORO ENTOMOLOGIA & ZOOLOGIA WWW.GIEFITALIA.ORG - INFO@GIEFITALIA.ORG
1. a. Legs present.......................... 2
b. Legs absent........................... 9 2. a. Three pairs of legs............... 15 b. More than three pairs of leg... 3 3. a. Four pairs of segmented legs 4 b. More than four pairs of segmented legs.......................... 6
4. a. Abdomen tapering into a tail, ending into a sting: arrow................ ...............................Scorpions (c.p.7) b. No tapering abdomen, no sting............................................ 5 5. a. Larger than 5 mm, with a strong carapace or an abdominal constriction between cephalotorax and abdomen: arrow...................... 23 b. Smaller than 5 mm, with no abdominal constriction.... Mites(c.p.6)
6. a. 5-7 pairs of legs with 2 pairs of antennas: arrows......... A c q u a t i c crustaceans (Gammarus, Talitrus & Nyphargus) (c.p.9) b. More than 5-7 pairs of legs evenly distributed over many (>3) body segments............................ 7 7. a. Body stout, oval, protected by segmented carapace, approximately 2-3 times longer than wide...........................Isopoda (c.p.9)
b. Segmented, elongated body, more than four times longer than wide............................................. 8 8. a. One pair of legs for each segment of the body, cerci (arrow) well developed.................................. .........Chilopoda (Centipedes) (c.p.5) b. 2 pairs of legs for each segment,cerci absent.................... .....Diplopoda (Millepedes) (c.p.5) 9. a. Shell present........Snails (c.p.8) b. Shell absent........................... 10
10. a. Not sclerotized cuticle.... 11 b. Sclerotized cuticle............ 14 11. a. Segmented body............ 12 b. No segmented body, with four tentacles (arrows) in head region.....................Slug (c.p.8) 12. a. Presence of a long breathing tube at the posterior end of the body: arrow................ .............Diptera Syrphidae (c.p.3) b. No breathing tube............ 13
13. a. Sclerotized and prominent head capsule: arrow....Diptera: Stratiomyidae, .............................. Trichoceridae (c.p.3) b. No head capsule, larvae generally whitish (maggot)......Diptera: Muscidae, Calliphoridae, Sarcophagidae, Piophilidae, Fannidae, Phoridae (c.p.3) 14. a. Sclerotized barrel, from cream coloured in the early hours of pupation, to brown or black......Diptera puparium (c.p.2) b. Withy-cream/yellowish eggs, laid in clusters, each element 3-5 millimetres long, slightly arched, about 5 times longer than wide.......Diptera egg (c.p.4)
15. a. Exposed wings...................... 16 b. Hidden wings (elytra?) or wingless .................................................... 18 16. a. Scaled wings (arrows)...Lepidoptera ................(butterflies and moths) (c.p.1) b. Membranous wings, scaleless and with visible veins.................. 17 17. a. One pair forewings (hind wings transformed in halters).......................... .............................Diptera (flies) (c.p.1) b. 2 pairs of wings (arrows)............... ............Hymenoptera (wasps) (c.p.1)
18. a. Three pairs of jointed legs; other segments membranous with or without prolegs.............................. 19 b. Three pairs of jointed legs; other segments sclerotized without prolegs.......................... 20 19. a. Only three pairs of thoracic legs: arrows...... beetle larvae (c.p.3) b. Three pairs of thoracic legs and prolegs (arrows) on the other body segments:.......... caterpillars (c.p.3)
20. a. Cerci: arrows on posterior region of the body ..... 21 b. No cerci......................... 22 21. a. Posterior, linear and segmented cerci: arrow............. ......Blattodea (cockroaches) (c.p.1) b. Hard posterior cerci, not segmented and clamp shaped: arrow.. ..........Dermaptera (earwigs) (c.p.1)
22. a. Sclerotized fore wings (elytra) generally covering the abdomen...... .............Coleoptera (beetles) (c.p.1) b. Not so, with a stalk (petiolum: arrow) connecting thorax and abdomen....................................... .....Hym. Formicidae (ants) (c.p.1) 23. a. With carapace, usually found near of watercourses and dump areas.......................... Crabs (c.p.9) b. No hard carapace, but adominal constriction: arrow.................. ..............................Spiders (c.p.7)
USEFUL REFERENCES AMENDT J., CAMPOBASSO C.P., GAUDRY E., REITER C., LEBLANC H.N., HALL M.J.R. 2007 - Best practice in forensic entomology standards and guidelines. International Journal of Legal Medicine, 121: 90-104. BORKENT A., MCALPINE J.F., WOOD D.M., Woodley N.E. 1989 Manual of Nearctic Diptera 3. Research Branch Agriculture Canada Monograph 32, VI+249 pp. BRUSCA R.C., BRUSCA G.J. 2002 - Invertrebrates Second Edition. Sinauer Associates, Inc., Publishers, 936 pp. CHAPMAN R.F. 1998 - The Insects Structure and Function 4th edition. Cambridge University Press, 770 pp. CHINERY M., 2007 - Domino Guide to the insects of Britain and western Europe. A&C Black London, 320 pp. GIBB J.T., OSETO C.Y. 2006 - Arthropod collection and identification, field and laboratory techniques. Elsevier, 312 pp. GOHRAM J.R. 1987 - Insects and mites in food, an illustrated key . USDA handbook n. 655, 767 pp.
GULLAN, P.J., CRANSTON, P.S. 2010 - The Insects An Outline of Entomology, Fourth Edition. Wiley-Backwell, 565 pp. INTRONA F., CAMPOBASSO C.P. 1998 - Entomologia forense, il ruolo dei ditteri nelle indagini medico-legali. Essebiemme editore, 191pp. MCALPINE J.F., PETERSON B.V., SHEWELL G.E., TESKEY H.J., VOCKEROTH J.R., WOOD D.M. (Coord.) 1981 - Manual of Nearctic Diptera 1. Research Branch Agriculture Canada Monograph 27, VI +674 pp. MCALPINE J.F., PETERSON B.V., SHEWELL G.E., TESKEY H.J., VOCKEROTH J.R., WOOD D.M. (Coord.) 1987 - Manual of Nearctic Diptera 2. Research Branch Agriculture Canada Monograph 28, VI +657 pp. MCGAVIN, G.C. 2011 - Essential Entomology An Order-by-Order Introduction. Oxford University Press, 318 pp. ROBINSON W.H. 2005 – Handbook of urban insects and arachnids. Cambridge University Press, 472pp. SCHAUFF M.E. (Ed.) 2010 - Collecting and preserving insects and mites. SEL-USDA updated and modified version of the USDA Misc. Publication no. 1443, 68 pp. SIRE M. 1967 - Les èlevages des petit animaux, 1 & 2 . Éditions Paul Lechevaliers, 906 pp. SMITH K.G.V. 1986 - A manual of forensic entomology. The trustees of British museum (Natural history) London, 205 pp. ZANGHERI P., 1976 - Il naturalista, esploratore, raccoglitore, preparatore, imbalsamatore. Hoepli, 504 pp.
Glossary Abdomen: the third (posterior) major division (tagma) of an insect body. Antenna (pl. antennae) Paired, segmented, sensory appendages, lying usually anterodorsally, on the head derived from the second head segment. Arthropods: Phylum belonging to the kingdom Animalia, composed by the classes of Insects, Spiders, Miriapoda and Crustacea. Common features are the exoskeleton covering the body, the body divided in segments and the jointed appendices. Body of insects: it's divided into three region: head or cephalic capsule, thorax and abdomen. Carapace: strongly sclerotized region of the exoskeleton. Cercus (pl. cerci): one of a pair of appendages originating from abdominal segment 11 but usually visible as if on segment 10.
Cuticle (adj. cuticular): the external skeletal structure, secreted by the epidermis, composed of chitin and protein comprising several differentiated layers. Elytron (pl. elytra) The modified, hardened, fore wing of a beetle that protects the hind wing. Exoskeleton: the external, hardened, cuticular skeleton to which muscles are attached internally. Head: the anterior of the three major divisions (tagmata) of an insect body. Larva (pl. larvae): An immature insect emerged from an egg, often restricted to insects in which there is complete metamorphosis (holometaboly), but sometimes used for any immature insect that differs strongly from its adult Leg: jointed appendix that allows movement. Insects have three pairs of legs, divided in seven articles: coxa, trochanter, femur, tibia, tarsus e pretarsus. Metamorphosis: the relatively abrupt change in body form between the end of immature development and the onset of the imaginal (adult) phase. Holometaboly: post-embryonic development of superior insects (Diptera, Coleoptera, Lepidoptera), divided in four key stages: egg, larva, pupa and adult. Petiole: the slender or narrow tubular segment between the Thorax and Abdomen. One or two-segmented in ants. Phylum: in biological terminology, the continuous succession of living forms, morfologically different but belonging from the same ancestor. In zoology, the systematic category between the kingdom and the class. Proleg: an unsegmented leg of a larva. Pupa (adj. pupal): the inactive stage between the larva and adult in holometabolous insects; also called chrysalis in butterflies. Puparium: the hardened skin of the final-instar larva (“higher� Diptera, Strepsiptera), in which the pupa forms. Sclerification: a process hardens the cuticle, creating chemical links between protein molecules. Sclerotized: subject to sclerification. Taxon (pl. Taxa): a taxonomic unit (species, Genus, Family, Phylum, etc.). Taxonomy (adj. taxonomic): the theory and practice of describing, naming, and classifying organisms. Thorax: the middle of the three major divisions (tagma) of the body, including prothorax, mesothorax, and metathorax, with three pairs of legs and two pairs of wings. Wings: the tergo-pleural expansion localized on the thorax,, that allow the insect to fly.