Fireflies, Glow-worms, and Lightning Bugs identification and natural history of the fireflies of the eastern and central united states and canada
Lynn Frierson Faust
features:
faust
Fireflies, Glow-worms, and Lightning Bugs
• More than 600 color photographs • Detailed accounts and anatomical diagrams of 75+ species, as well as aids in distinguishing between similar species • A first-of-its-kind flash-pattern chart that folds out on heavyweight paper • Extensive scientific details written in an understandable and engaging way • Colorful common names—Twilight Bush Baby, Shadow Ghosts, Snappy Syncs, and more— for easy species identification based on flash patterns
lynn frierson faust is an advisory consultant on firefly studies with state and national parks in Tennessee, South Carolina, Mississippi, Pennsylvania, and New York and an on-site scientific consultant with BBC Nature, the Discovery Channel, and National Geographic, among many other media outlets. She has also aided in identification and educational advisement for the Cincinnati Museum Center and published surveys of the fireflies of Mammoth Cave National Park, Congaree National Park, and the Allegheny National Forest. Faust has presented around the world on the topic of fireflies and published numerous scientific papers. She lives in Knoxville, Tennessee.
cover design: Erin Kirk New cover photo: David Hughes author photo: Courtesy of the author
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• Tips on ideal sites and times of year for firefly watching • Conservation-oriented approach “This is a true gem of a book, a celebration of fireflies in all their diversity. With her unique combination of expert knowledge, boundless enthusiasm, superb photography, and above all her love of these magical creatures, Lynn Faust leads us through every aspect of their lives and emphasizes the need to enjoy, study, cherish, and protect them. She has created a supremely authoritative yet wonderfully accessible guide that is sure to inspire and inform the next generation of firefly researchers. This book will draw you into the world of fireflies and make you want to go out into the night to discover and enjoy them for yourself.”—john tyler, past Fellow of the Royal Entomological Society, and author of The Glow-Worm
the university of georgia press Athens, Georgia 30602 www.ugapress.org
ISBN 978-0-8203-4872-8
Fireflies, Glow-worms, and Lightning Bugs identification and natural history of the fireflies of the eastern and central united states and canada
Lynn Frierson Faust
Fireflies, Glow-Worms, and Lightning Bugs is the firstever comprehensive firefly guide for eastern and central North America. It is written for all those who want to know more about the amazing world of lightning bugs and learn the secrets hidden in the flash patterns of the 75+ species found in the eastern and central United States and Canada. As an independent researcher working with numerous university teams, naturalist Lynn Frierson Faust, “The Lightning Bug Lady,” has spent decades tracking the behavior and researching the habitats of these fascinating creatures. Based on her twenty-five years of fieldwork, this book is intended to increase understanding and appreciation of bioluminescent insects while igniting enthusiasm in a fun and informative way. Species accounts are coupled with historical backgrounds and literary epigraphs to engage and draw readers young and old into the world of these tiny sparklers. A chart documenting the flash patterns of the various species will aid in identification. Clear photos illustrate the insects’ distinguishing physical characteristics, while habitats, seasonality, and common names are provided in easy-to-understand yet scientifically accurate language. The guide will be welcomed by everyone who wants to learn more about fireflies’ and glow-worms’ unique traits and fragile niche in the ecosystem.
georgia
10/4/16 1:55 PM
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s, and Lightning Bugs identification and natural history of the fireflies of the eastern and central united states and canada
Lynn Frierson Faust The University of Georgia Press  Athens
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A Wormsloe Foundation Nature Book © 2017 by the University of Georgia Press Athens, Georgia 30602 www.ugapress.org All rights reserved Designed by Erin Kirk New Set in Minion and Whitney Printed and bound by Four Colour Print Group The paper in this book meets the guidelines for permanence and durability of the Committee on Production Guidelines for Book Longevity of the Council on Library Resources. Most University of Georgia Press titles are available from popular e-book vendors. Printed in China 21 20 19 18 17 p 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data Names: Faust, Lynn Frierson, author. Title: Fireflies, glow-worms, and lightning bugs! : Identification and Natural History of the Fireflies of the Eastern and Central United States and Canada / Lynn Frierson Faust. Other titles: Identification and natural history of the fireflies of the eastern United States and Canada | Wormsloe Foundation nature book. Description: Athens, Georgia : University of Georgia Press, [2017] | Series: A Wormsloe Foundation nature book | Includes bibliographical references and index. Identifiers: lccn 2016004962 | isbn 9780820348728 (pbk. : alk. paper) Subjects: lcsh: Fireflies—United States. | Fireflies—Canada. Classification: lcc ql596.l28 f38 2017 | ddc 595.76/44—dc23 lc record available at http://lccn.loc.gov/2016004962
preceding pages: The Light Show happens in June at Elkmont in the gsmnp. (Ted Faust)
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Contents List of Species by Scientific Name x preface For the Awe of It xiii Acknowledgments xv 1
What Genus Is It? 1
2
Fireflies Around the World 11
3
Frequently Asked Questions 17
4
Eggs, Larvae, and Pupae 39
5
Survival Tactics and Mimicry 49
6
Parasites and Predators 55
7
Fieldwork, Research, and Filming 63
8
Species Accounts by Genus 71 Ellychnia 73 Lucidota 78 Micronaspis 86 Phausis 91 Phengodes 107 Photinus 112 Photuris Disclaimer 180 Photuris 186 Pleotomus 259 Pollaclasis 264 Pyractomena 267 Pyropyga 302
appendix The Selangor Declaration 313 Photo Credits 319 Permissions 323 Glossary 325 Bibliography 333 Online Resources 343 Index of Common Names 345 Subject Index 347
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Species by Scientific Name Ellychnia corrusca (Winter Firefly) 73 Lucidota atra (Woodland Lucy) 78 Lucidota punctata (Tiny Lucy) 82 Micronaspis floridana (Florida Intertidal, Mangrove, Fiddler Crab Firefly) 86 Phausis inaccensa (Shadow Ghost) 91 Phausis luminosa (Luminous Ghost) 97 Phausis reticulata (Blue Ghost, Appalachian Glow-worm Firefly) 100 Phengodes (Railroad-worm) 107 * Photinus ardens (Northern Ablaze Flash-train) 162 Photinus australis (Twilight Bush Baby) 112 Photinus brimleyi (Sidewinder) 116 Photinus carolinus (Smokies Synchronous Firefly, Light Show) 121 Photinus collustrans, P. tanytoxus (Florida Fishhook) 127 * Photinus consanguineus (Double Cousin) 152 Photinus consimilis (Cattail Flash-train Firefly) 132 Photinus cooki (Cook’s Firefly, Fairy Ring Firefly) 136 Photinus floridanus (Florida Sprite) 140 * Photinus greeni (Green’s Firefly) 152 Photinus ignitus (Ignited Firefly) 144 Photinus indictus (Silent Firefly) 148 Photinus macdermotti (Mr. Mac) 152 Photinus marginellus (Little Gray) 157 Photinus obscurellus (Murky Flash-train) 162 Photinus pyralis (Big Dipper, J-Stroke) 166 Photinus sabulosus (Creekside Tree Blinkers) 172 Photinus scintillans (Pale Firefly, Yellow-Bellied Firefly, Pine Barrens Firefly) 176 * Photinus texanus (Texas Tinies) 160 * Photuris bethaniensis (Bethany Beach Firefly) 227 Photuris caerulucens (Slow Blues) 186 Photuris “Chinese Lanterns” (Chinese Lanterns, Low Slow Glows) 190 Photuris congener (Florida Single Snappy) 197 Photuris “F” (Loopy 5) 201 * Photuris fairchildi (Fairchild’s Predator) 254 Photuris frontalis (Snappy Single Sync) 205
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Photuris hebes (Heebie-Jeebies) 211 Photuris lloydi (Lloyd’s Predator) 216 Photuris lucicrescens (July Comets, Big Scaries) 222 Photuris mysticalampas (Mystic Lanterns) 227 Photuris pennsylvanica (Dot-dash, Pennsylvania Firefly) 233 * Photuris potomaca (Potomac Firefly) 254 Photuris “Primitive Unnamed” (Treetops and Flashbulbs) 237 Photuris tremulans (Christmas Lights) 242 Photuris versicolor (Variable Triple Flash) 248 Photuris versicolor var. quadrifulgens (Spring 4-Flasher) 253 * Pleotomodes knulli and P. greeni (Anthill Firefly) 7 Pleotomus davisii (Davis’s Oddball) 259 Pollaclasis bifaria (Branched Polly) 264 Pyractomena angulata (Candle, Angled, or Say’s Firefly) 267 Pyractomena borealis (Spring Treetop Flasher) 271 Pyractomena dispersa (Marsh Flicker) 277 * Pyractomena dispersa, western states only (Wiggle Dancer) 277 Pyractomena linearis (Marsh Gray) 282 Pyractomena lucifera (Marsh Imp) 286 Pyractomena marginalis (Marginal Firefly) 291 Pyractomena “mystery blue” (Mystery Blue) 294 Pyractomena palustris (Marsh Diver) 298 * Pyractomena punctiventris (Texas Hookers) 281 Pyropyga decipiens (Sneaky Elf) 302 Pyropyga minuta (Flower Elf) 307 * Pyropyga nigricans (Black-Bordered Elf) 302, 307 * Tenaspis angularis (Tropic Traveler) 7 * Species does not have its own account but appears in the text, charts, or other species accounts.
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The eerie glows of Blue Ghosts are a backdrop to the Light Show. (Hugh Faust)
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preface For the Awe of It One steamy June afternoon, six firefly researchers and members of film crews from around the world arrived at the Knoxville, Tennessee, airport. We assembled a mountain of field gear and cameras in the baggage area. Team member Dr. Sara Lewis of Tufts University, while waiting on her final bag, stepped over to the rental car counter. Without a moment’s hesitation after examining Sara’s license, the smiling lady behind the counter asked in her soft southern drawl, “So, you are from Boston. Did you come here to see our lightning bugs?” We all looked at her, amazed. For once, we were in relatively clean and presentable street clothes. Our collective hair was combed. None of us had our pockets stuffed with collecting vials, nor were we wearing our funky firefly-hunting headlamps or carrying (our still collapsed and packed) giant nets. We had yet to earn the black circles under our eyes from late nights spent in the dark forest. How did this lady know we indeed were all here “for the lightning bugs”? Sara was intrigued and sidestepped the question by instead asking the car rental lady, “Have you seen the Light Show in the Smokies?” The lady put on a huge grin and told us how her family tried to spend an evening with the now-famous synchronous fireflies every summer at Elkmont, a former logging village in the Great Smoky Mountains National Park. Sara then posed the question, “Why do you put up with all the hassle of dealing with the National Park Service mandatory shuttles, the ticket system, the long wait, the lines and crowds?” The car rental lady, pausing for a moment, her eyes with a dreamy, faraway look, replied, “I guess it’s for the awe of it.” Because of this universal awe, I have written this book to help enlighten all who are interested in understanding a little more about the lives, natural history, identities, and diversity of our awesome North American fireflies.
In the evening thousands of fire-flies in the garden, like flying fire. I had never seen them before. Quite a fantastic sight. —Dietrich Bonhoeffer, German pastor and World War II martyr, in Connecticut, 1939
xiii
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Fireflies, Glow-worms, and Lightning Bugs
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1 What Genus Is It? This guide was written to bring out the inner naturalist in each of you, regardless of your scientific training or lack thereof. It is the book I wanted twenty-five years ago when I began my firefly journey. At that time I could only access very questionable information from children’s lightning bug books at my public library. For ease of use to all, the fireflies are arranged in abc order by genus and species instead of taxonomic order. Phonetic pronunciations of the scientific names are provided for each. Go ahead and at least try to say the scientific names out loud in a private place! To keep distractions to a minimum, authority names (the person who first described each firefly) are listed at the end of each “research” section following the explanation of the historical meaning (etymology) of these often mind-boggling species names. (In scientific writing, the authority names follow the first use of the scientific name.) Formal citations are not used within the text, though the authors and years are incorporated to steer you to the extensive bibliography for the original research. First and foremost, enjoy your lovely fireflies displaying! Then I want you to begin to really notice how an individual lightning bug flashes within his group. Now look at the flash chart and the firefly diagrams. The flash charts illustrate male flash patterns except where noted. The firefly diagrams show the different genera side by side and the body parts. Then answer the simple questions that follow:
So First Woman sent Glowworm to the east and told Fox Fire to go to the south, Lightning Beetle to the west, and Firefly to the north. Then, when anyone needed extra light, these four were ready to serve him.—As told to ethnoanthropologist Franc Johnson Newcomb in the early 1900s by elders of the Diné (Navaho)
1 What is the general flash pattern of an individual firefly? Do
you see single flashes or predictable groups of flashes (flashtrains)? Be aware that hot nights will cause all fireflies to flash faster, cold nights slower. Say “one Mississippi, two Mississippi,” and so on, to count the flash rate, or, better still, use a stopwatch or voice recorder app. If the flash is rhythmic, as most will be, describe the flash-dark cycle; for example, “It repeats its flash (or flash-train) every six seconds.” 2 What month and season is it? At what time of day or night do you see this firefly most active? Each species generally appears at a specific time of day or night during a specific time of year, for example, May versus July, night or dusk or day.
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2
Chapter 1
3 In what habitat (e.g., forest, marsh, open fields, trees) are most of these fire-
flies displaying? Fireflies are usually very habitat specific.
4 What genus is it? Determine genus by reading the short descriptions in this
chapter and studying the photos. Don’t worry about species now. Later, as you become more experienced, you will begin to use the small physical differences noted in the photos and descriptions in the species chapters.
Relative size: large Photuris, medium Lucidota, small Phausis, tiny Pyropyga.
All fireflies are small, but you will see these four very general descriptive terms at the beginning of each species chapter just to help you visualize their relative size:
Large, 0.5 in. (13+ mm) or larger
Medium, 0.4 in. (9–12 mm) Small, less than 0.3 in. (under 8 mm) Tiny, 0.2 in. (4–6 mm)
Very generally, each species will be particularly abundant and noticeable for one to two weeks a year before declining or being replaced by the next species. Florida and Deep South species occasionally are present in lower numbers for many months or peak twice a year.
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What Genus Is It?
3
The two most commonly seen flashing genera: Photinus (left, middle) and Photuris (right).
What genus is it? Does it flash, flicker, or glow briefly during flight? Photuris, Photinus, Pyractomena Does it glow continuously up to sixty seconds while slowly flying low? Phausis Is it day active, with no pale borders on wing covers and no functioning lanterns? Ellychnia, Lucidota, Pyropyga Six genera are rare to very uncommon, are specialized, have a limited range, or are not quite fireflies: Pollaclasis, Micronaspis, Tenaspis, Pleotomus, Pleotomodes, Phengodes Soldier beetle and net-wing mimics and other insects often look much like fireflies in coloration, shape, and flight. Mimics’ heads cannot completely hide under a head shield as fireflies’ heads do. Mimics lack lanterns and may have wing covers that may have ridged, net-like squares and that are not generally smooth like those of fireflies. (Please see the photos in the mimicry section of chapter 5, “Survival Tactics and Mimicry.”)
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3 Frequently Asked Questions People everywhere are curious about fireflies, from the how and why of their magical flashing to details of their courtship habits and life histories. These little amenity beetles we call lightning bugs or fireflies are neither agricultural pests, creepy crawly scary-type insects, venomous biters, stingers, nor gruesome predators (Photuris the one huge exception!). For this reason, fireflies, or lampyrids, make especially good ambassadors for creating a deeper understanding of all insects and the place we all share in our natural world. In the twenty-plus years that I have given talks to friends, civic groups, natural history and garden associations, churches, and academics, many of my listeners have asked the same questions over and over. It is touching and encouraging to witness the same childlike wonder in the eyes of questioners no matter their age. The following questions and simplified answers represent many of the most common questions. Those wanting to know more explicit scientific details will want to refer to the bibliography and website section for detailed research-based literature on their topic of interest.
Fix me a toddy, Lola, and we’ll sit on the gallery of Tara and you play a tune and we’ll watch evening fall and lightning bugs wink in the purple meadow.—Walker Percy, Love in the Ruins
Shuttles bring 1100 people/night
Smokies crowds wait for the Firefly Shuttle to see the Light Show given by P. carolinus males. (Raphaël De Cock, right photo)
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18
Chapter 3
Fireflies come in many shapes and sizes; a larger Pyractomena grabs a small, white Phausis. Both are females.
What exactly are fireflies? These insects are beetles, like ladybugs and June bugs, and are not flies or true bugs. Their insect order, Coleoptera, means “sheath wing” (koleos, “sheath,” and ptera, “wing”), which describes the hard modified outer wings called “elytra” that all beetles have. They unfurl and fly with their second set of wings, which are hidden beneath the protective elytra. Lightning bugs undergo complete metamorphosis, meaning they go from egg to larva to pupa to adult over a period of one to two years. To be in the firefly family, Lampyridae, the larvae must have the ability to glow, and the adults must have a hard head shield (pronotum) that can completely cover the head, among other requirements. What is the difference between a firefly, a lightning bug, and a glow-worm? Carl Linnaeus first used the term firefly in 1767. He specifically intended to imply those beetles that flashed. Today, in the United States, there is no difference in meaning between the two terms firefly and lightning bug. These names usually reflect regional differences in terminology, with fireflies generally being a more northern U.S. term and lightning bugs being the more southern term for these flashing sprites. The term glow-worm can get a little more confusing. All around the world, some firefly species have flightless females that glow even when their males have lost their lanterns through evolution. The eastern United States has several of these species, and the western states proportionately even more. These larva-like females are called “glow-worms” or “glow-worm fireflies.” All firefly larvae and pupae, regardless of species, can glow and are also called glow-worms. There is the fabulous pinky-finger-sized “not-quite-a-firefly” creature called a “Railroad-worm” (Phengodes) whose wormlike females and larvae brightly glow with eerie green spots and lines that resemble trains at night. These Phengodes are also called glow-worms. Finally, there are the minute bluish
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Frequently Asked Questions
19
glowing points of light emitted by the almost microscopic “bioluminescent fungus gnat larvae.” This impossibly long, tongue-tying name simply means “glowing gnat babies.” Resembling tiny earthbound constellations in certain moist soils, these fly larvae are also called glow-worms. These Orfelia fultoni fungus gnat larvae are kin to the famous Waitomo New Zealand Cave glowworms and are not even beetles. So as long as you know the various glow-worm choices, you will be in good shape to figure out what someone else is talking about. As you digest the species pages and photos in this book, this glow-worm confusion should begin to clear.
Left to right, top to bottom. All these are called “glow-worms”: Photuris, Photinus larvae; larval glow; pupal glow; Phausis females and the female glow; Phengodes larva and glow. (David Liittschwager, Phengodes)
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8 Species Accounts by Genus
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Ellychnia corrusca
73
Winter Firefly Ellychnia corrusca
Ee-LICK-nia core-US-cah 9–18 mm
Quick ID: Large, wide, black, day active firefly with no lanterns, often seen in late fall and winter on tree trunks or in early spring flying in woods. Appearance: Medium to large, 0.3–0.7 in. (9–18 mm) long. Wide bodied. Pronotum (head shield) has two yellow and pink “parentheses” between the black central mark and side edging. Ridged dark elytra (wing covers) are covered with fine hairs that in certain light conditions have an almost greenish or golden tint. Rarely, some adults have one or two pale terminal (end) abdominal segments on their normally dark abdomens. Females are often slightly larger and wider than males. The keen eyed can identify the males by their squared-off terminal segment versus the more pointed female final segment. The dark, thick-bodied, bristled larvae grow up to 0.75 inch (17 mm), are pink sided, and glow from two larval lanterns.
My dear, he sounds like all plug and no spark to me, you know, all bug and no lightning. —Bill Balance, twentieth-century radio talk show host
Flash behaviors: Day active (diurnal), no flash, no glow, no lanterns. Heavy, slow, “heads-up” flyers, seen most often midday on warm spring days. Mating often occurs on tree trunks. Time of year, time of night/day: Adults appear in fall or winter on the south sides of colony trees, which are often larger diameter oaks, tulip poplars, and certain hickories. The trees of the fireflies’
Ellychnia corrusca is winter and day active.
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Yellowish fuzz on pronotum and ribbed elytra are visible on this male Ellychnia corrusca.
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Chapter 8
Ellychnia pronotum is rounded and has yellow and pink parentheses bounded by black.
Male Winter Firefly terminal abdominal segments are fleur-de-lis shaped.
Male Ellychnia have a truncate end (pygidium) with four subtle points.
Female Ellychnia corrusca have a triangular final segment, like most firefly females. Female Winter Firefly has pointed final segment for egg laying. Female Ellychnia corrusca are wider bodied.
Ellychnia cling to their colony trees, larger-diameter oaks and tulip poplars, in freezing temperatures. Though they overwinter as adults together on trees, Ellychnia mate in March and April.
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Ellychnia corrusca
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colony sites are used year after year by succeeding generations. Their dispersal and mating flight occur as early as mid-March through April. Most are gone by early May in the southern Appalachians and by late June farther north. mGDD 0–1100. Habitat: Seen most often in maturing hardwood forests, margins, yards, and open parks with large trees, but occasionally found almost everywhere. Range: Common. Widespread across the eastern United States and Canada. Similar species: Only Lucidota atra fireflies, also lanternless, might be mistaken for these Winter Fireflies. Unlike the smaller June-flying Lucidota atra, that have massive, flattened antennae, Ellychnia corrusca are found much earlier in the year, are larger, and have heavily ridged elytra, relatively thinner, shorter antennae, and the characteristic yellow and red “parentheses� marks on their pronota. Ellychnia corrusca is currently considered a species complex, meaning several similar species of Ellychnia might be represented in the eastern United States. Future revisions by experts may again split this species back into the three older eastern species of E. lacustris, E. autumnalis, and E. corrusca, since wide size variations and some behavioral and seasonal differences are found, especially in the northeastern United States. Additional Ellychnia species are found out west. For now, anytime you find a lanternless large dark firefly, especially in months when most fireflies are gone, it is most likely the Winter Firefly.
Lanternless Ellychnia corrusca (left) and Pyractomena borealis (right) are active in the same seasons and habitats.
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