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A Field Guide to the Tiger Beetles of the United States and Canada: Identification, Natural History, and Distribution of the Cicindelidae DAVID L. PEARSON C. BARRY KNISLEY CHARLES J. KAZILEK OXFORD UNIVERSITY PRESS www.ebook3000.com

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  • A Field Guide to theTiger Beetles of the

    United States and Canada:Identification, Natural

    History, and Distribution of the Cicindelidae

    DAVID L. PEARSONC. BARRY KNISLEY

    CHARLES J. KAZILEK

    OXFORD UNIVERSITY PRESSwww.ebook3000.com

  • A Field Guide to the Tiger Beetlesof the United States and Canada

    www.ebook3000.com

  • A Field Guide to the

    D AV I D L . P E A R S O N

    C . B A R R Y K N I S L E Y

    C H A R L E S J . K A Z I L E K

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  • Tiger Beetles of the United States and Canada

    Identication,

    Natural History,

    and Distribution

    of the

    Cicindelidae

    12006

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  • 3Oxford University Press, Inc., publishes works that furtherOxford Universitys objective of excellencein research, scholarship, and education.

    Oxford New YorkAuckland Cape Town Dar es Salaam Hong Kong KarachiKuala Lumpur Madrid Melbourne Mexico City NairobiNew Delhi Shanghai Taipei Toronto

    With ofces inArgentina Austria Brazil Chile Czech Republic France GreeceGuatemala Hungary Italy Japan Poland Portugal SingaporeSouth Korea Switzerland Thailand Turkey Ukraine Vietnam

    Copyright 2006 by Oxford University Press, Inc.

    Published by Oxford University Press, Inc.198 Madison Avenue, New York, New York 10016www.oup.com

    Oxford is a registered trademark of Oxford University Press

    All rights reserved. No part of this publication may be reproduced,stored in a retrieval system, or transmitted, in any form or by any means,electronic, mechanical, photocopying, recording, or otherwise,without the prior permission of Oxford University Press.

    Library of Congress Cataloging-in-Publication DataPerason, David (David L.)

    A eld guide to the tiger beetles of the United States and Canada :identication, natural history, and distribution of the Cicindelidae /David L. Pearson, C. Barry Knisley, and Charles J. Kazilek.

    p. cm.ISBN-13: 978-0-19-518155-5; 978-0-19-518156-2 (pbk.)ISBN: 0-19-518155-7; 0-19-518156-5 (pbk.)

    1. Tiger beetlesCanada. 2. Tiger beetlesUnited States.I. Knisley, C. Barry. II. Kazilek, Charles J. III. Title.

    QL596.C56P429 2006595.762dc22 2004020220

    9 8 7 6 5 4 3 2 1

    Printed in the United States of Americaon acid-free paper

    www.ebook3000.com

  • For all the information that has accumulated about tiger beetles over the last200 years, and for the unagging interest this group of insects has engen-dered, it is strange that no single identication eld guide has been availablefor the United States and Canada. Recent regional eld guides for variousstates and provinces have certainly been an important boon to lling this needand broadening the interest in tiger beetles. However, those who live in anarea not covered by these guides or who have an interest in tiger beetles on acontinental scale have had to assemble bits and pieces of information from thescientic literature. Enjoyment of this group of insects has thus been largelyreserved for those amateur enthusiasts and professional workers who have theinterest and time to wade through dozens of obscure journals and then inter-pret the often arcane terms. The journal Cicindela has been a great help in pro-viding information about tiger beetles over the last 25 years, but its readershiphas remained fairly static. We think that there are a large number of youngpeople, established naturalists, and outdoor enthusiasts who, if given themeans to recognize and easily identify tiger beetles, would add tiger beetles toother watchable animals and plants such as birds, butteries, dragonies, andorchids. This in turn could make tiger beetles not only better known for theirbeauty , but it could also greatly enhance our knowledge of tiger beetle natu-ral history and distribution in the United States and Canada.

    We strove to write the guide in a pleasant and comprehensible style withlimited scientic jargon and concepts. Even more basic, however, was resolvingsimple problems such as developing an acceptable list of common names. Overalmost a year, an ad hoc committee of 10 stalwart volunteers sifted throughsuggestions and debated details. We even enlisted the entire readership of Ci-cindela to vote for their favorite common names and to provide suggestions foralternatives. The resulting selection was a cautious consensus, and these arethe common names we use here.

    We also knew that the color identication plates would be essential to thisfield guide if we were to meet our goals. These plates needed to be artisticallypleasing as well as scientically accurate if the eld guide was to be useful andattract many new enthusiasts. Charles Kazilek, head of the Visualization Lab-oratory in the College of Life Sciences, Arizona State University, worked dili-gently and with great passion on the 24 color plates that grace this eld guide.Without his work and partnership in this effort, the eld guide would not

    v

    Preface

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  • have been possible. With real specimens and the magic of digital photographyand Adobe Photo Shop, he painted the illustrations with pixels in all theirglory and color, but without sacricing identication details.

    To write this eld guide, we relied not only on our combined 75 years ofexperience studying tiger beetles, but we unabashedly drafted the help of manyof our colleagues. They generously shared their knowledge and interest intiger beetles, so that we could assemble as complete a picture as possible ofthe identication, distribution, natural history, and habitat details of the 109species of tiger beetles occurring in North America north of Mexico. Thosewho provided indispensable information and advice included John Acorn,Chris R. Brown, Richard Freitag, Wyatt Hoback, Michael Kippenhan, DavidW. Middleton, W. Dan Sumlin III, and Steve Spomer. Most critical, however,were the many suggestions and insights from David Brzoska and RonaldHuber, whose depth of experience with tiger beetles is legendary. Photographsof live tiger beetles in the eld were generously supplied by Stephen Spomer,Christopher Brown, Kevin Fielding, and Edward S. Ross.

    Finally, but certainly not least, we thank our wives, Nancy Pearson, PeggyKnisley, and Sally Kazilek, for their patience and support over the years.

    Preface

    vi

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  • 1 The Magic of Tiger Beetles 3

    2 How to Recognize a Tiger Beetle 7

    3 Phylogeny and Taxonomy 15

    4 Illustrated Keys to Adult Genera and Species 19

    5 Identication of Tiger Beetle Larvae 43

    6 Species Accounts 47Giant Tiger Beetles, Genus Amblycheila 48

    Night-stalking Tiger Beetles, Genus Omus 52

    Big-headed Tiger Beetles, Genus Tetracha/Megacephala 57

    Common Tiger Beetles, Genus Cicindela 60

    Temperate Tiger Beetles, Subgenus Cicindela 61

    Tribon Tiger Beetles, Subgenus Tribonia 105

    American Tiger Beetles, Subgenus Cicindelidia 113

    Habro Tiger Beetles, Subgenus Habroscelimorpha 138

    Eunot Tiger Beetle, Subgenus Eunota 147

    Coral Beach Tiger Beetles, Subgenus Microthylax 148

    Opilid Tiger Beetles, Subgenus Opilidia 149

    Little Tiger Beetles, Subgenus Brasiella 150

    Rounded-thorax Tiger Beetles, Subgenus Cylindera 152

    Dromo Tiger Beetles, Subgenus Dromochorus 159

    Ellipsed-winged Tiger Beetles, Subgenus Ellipsoptera 162

    7 Ecology and Behavior 177

    8 Biogeography 189

    9 Conservation 191

    10 Observing and Studying Tiger Beetles 199

    Selected Bibliography 209

    Checklist of the Tiger Beetles of the United States and Canada 213

    Index 221

    Contents

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  • A Field Guide to the Tiger Beetlesof the United States and Canada

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  • Hundreds of otherwise normal people are passionate about an intriguing groupof insects called tiger beetles (family Cicindelidae). These cicindelophiles or tigerbeetlists can be found swinging insect nets to collect wary tiger beetles fromsandy pine forests in Florida to alpine meadows in the Canadian Rocky Moun-tains. Others might spend hours crawling on elbows and knees in the piercingheat of an Arizona grassland for close-up photos of a ruby-red species. A few sitpatiently on the white sands of a New Jersey beach taking notes about the mat-ing behavior of a long-legged tiger beetle that is listed by the United States gov-ernment as an endangered species. These activities and others unite a diversegroup of tiger beetle enthusiasts, only a few of whom are professional entomol-ogists. Tiger beetles elicit something more than a routine response to the neces-sities of employment. Note the highly enthusiastic and curious behavior of somelawyers, dentists, prison guards, railroad workers, and computer engineers whohave found a life-long hobby in beetle watching. If there is some kind of magicemitted by tiger beetles, what is it, and how has it captured the interest of somany people regardless of whether they are being paid for it or not?

    This is a question we are asked frequently, and its not one that can beeasily or logically explained. All we know is that you have to be exposed to atiger beetle to discover if this passion lies inside you, too. For some, such ex-posure comes from seeing a group of spectacularly colored specimens pinnedin perfect rows in a glass-topped insect drawer. For many others, it happenswhen they notice a live tiger beetle for the rst time on a forested path, alonga river bank, or in some other place that may have been taken for granted untilthat moment. We know that this interest in tiger beetles is not mystical, but ifyou talk to tiger beetle acionados about their hobby, most of them will notbe able to explain the source of what the uninitiated may see as a mania.

    A large part of the reason we decided to write this eld guide was to per-suade others that tiger beetles are special. This book should facilitate an in-terest in tiger beetles by amateurs and professionals alike because it is the rstcombined source of illustrated identication, natural history, and distributionfor all the species and subspecies of tiger beetles known to occur in the UnitedStates and Canada.

    Color plates of each species, subspecies, and many intermediate formswill allow readers to use this book to directly compare beetles in the eld ormounted specimens in a collection with the pictures. For others who might

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    1The Magic of Tiger Beetles

  • consider this method of comparing specimens with pictures too arbitrary, weprovide simple keys. The couplets in these keys are generously supplied withline drawings of pertinent morphological features to reinforce the distin-guishing descriptions and terms. Although the keys concentrate primarily onadult characters, an abbreviated key to the larval forms is also provided to thelevel of genera. In addition, detailed species accounts are provided, which in-clude information on both adult and larval behavior, habitat, similar species,and other data useful for recognizing species and subspecies and when to ex-pect to nd them in the eld.

    More than 2600 species of tiger beetles have been described to date, andthey are found all over the worlds land surface except Antarctica, the Arcticnorth of 65 latitude, Tasmania, and some isolated oceanic islands like Hawaiiand the Maldives. In altitude they range from about 3500 m above sea levelto 220 m below sea level. In North America north of Mexico there are 109 spe-cies, which have been divided into an additional 114 recognized subspeciesor geographically distinct races. Detailed studies of their natural history, pop-ulation dynamics, communities, patterns of worldwide species richness, andtaxonomy of particular subgroups have produced much information. Tigerbeetles, as a result, are among the most widely investigated families of insects,especially in terms of their ecology and geographic distribution. The details ofthe existing wealth of biological information has been synthesized in TigerBeetles: The Evolution, Ecology, and Diversity of the Cicindelids, by D. L. Pearsonand Alfried Vogler (2001), which serves as a companion book to this eldguide. Four regional publications also emphasize identication and naturalhistory of tiger beetles in parts of North America: The Biology of Tiger Beetlesand a Guide to the Species of the South Atlantic States, by Knisley and Schultz(1997); Northeastern Tiger Beetles: A Field Guide to Tiger Beetles of New Englandand Eastern Canada, by Leonard and Bell (1999); Tiger Beetles of Alberta: Killerson the Clay, Stalkers on the Sand, by Acorn (2001); and Tiger Beetles: A FieldGuide and Identication Manual for Florida and Eastern U.S., by Choate (2003).For distribution of tiger beetle species, we used maps in these publications aswell as many articles in the quarterly journal Cicindela. Numerous web sitesare available electronically for recent tiger beetle information at a local or statescale, and we perused them frequently for pertinent updates to make this eldguide as current as possible.

    In this day of genomic studies, stem cells, and molecular clocks, a eldguide to a family of beetles may seem antediluvian to some. However, it is asmall jump from cellular studies to placing names and associating distributionand natural history with beetles such as these. Tiger beetles have alreadyproven to be ideal models for understanding many other parts of the biospherethat are themselves so complicated that they hinder advances in our knowl-

    Tiger Beetles of the United States and Canada

    4

  • edge. Studies of tiger beetle mitochondrial and nucleic DNA have begun toopen doors of comprehension that extend to many other organisms. Investi-gations of reectance mechanisms of tiger beetle colors, ultrasound hearing,visual systems, exceptional genetic anomalies, and patterns of species distri-butions across continents have all been pioneered using tiger beetles. How-ever, without names to attach to populations and species and without basicknowledge of natural history and distribution, these and other sophisticatedstudies would be much more difcult if not impossible. For those who needless justication for a eld guide, basic procedures, such as putting names onliving or dead specimens, can be a means of deepening a relationship betweenobserver and beetle as well as facilitating communication among enthusiasts.

    The Magic of Tiger Beetles

    5

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  • Tiger beetles form a distinct group of species within the Order Coleoptera,which contains all the beetles. They are included by some authors as a distinctsubgroup (subfamily Cicindelinae or Tribe Cicindelini) within the family ofground beetles called Carabidae. Most entomologists, however, consider tigerbeetles to form their own family, Cicindelidae, and they share many charac-ters in common with and are most closely related to the predaceous groundbeetles (Carabidae), predaceous diving beetles (Dytiscidae), whirligig beetles(Gyrinidae), and crawling water beetles (Haliplidae). These ve families anda few others are placed together as a suborder called Adephaga. Four generaof tiger beetles occur in North America, Omus, Amblycheila, Tetracha, andCicindela, and several characters in combination reliably distinguish tiger beetles from all other groups of Adephaga: (1) long, sickle-shaped mandibles;(2) simple teeth arranged along the inner side of the mandible with a com-pound (molarlike) tooth on the inner base of each mandible; (3) long, thin an-tennae with 11 segments and attached to the head between the eye and baseof the mandible; (4) long body form with eyes and head together wider thanthe thorax; (5) long, thin running legs; (6) tunnel-building behavior of the lar-vae; and (7) peculiar forward-facing sets of hooks on the backs of the larvae.

    Most adult tiger beetle species look remarkably similar in body shape,proportions, and behavior. They vary primarily in size, color, and shape ofmarkings. In North America the smallest species is barely 7 mm long, whilethe largest is more than 70 mm. Many species are dull black, but some spe-cies are brilliantly emblazoned with bright green, violet, blue, red, and yellowcolors. Most species have streamlined bodies and long, slender legs for fastsprinting across the ground or vegetation. The prominent eyes of these visualhunters are usually so large that they make the head wider than the relativelynarrow thorax. Adults have transparent hind wings that are usually foldedand hidden under the hard front wings, the elytra. In ight, these elytra con-veniently open forward to allow the ight wings underneath to unfold and ex-tend out to the sides. The wings are used for short and low escape ights frompredators. A few species, however, use their wings for long-range dispersion,whereas a few others have lost these ight wings and are earthbound.

    On the ground, where most species spend their lives, tiger beetle adultstypically run in short, fast spurts interspersed with brief stops. The stops arenecessary because the beetles literally run so fast that they cannot see their

    7

    2How to Recognize a Tiger Beetle

  • prey. During their stops, they search for moving insects. If it sees a potentialprey item, such as an ant, a small spider, or a y, the tiger beetle quickly turnsin that direction and waits for another movement. The tiger beetle then runsthe prey down and, if successful, grabs it with its long, thin, sickle-shapedmandibles. These mandibles are used to chew the prey into a puree. Thebeetles mandibular glands near the base of each mandible release enzymesthat begin the digestion process. The uid is conducted from the gland to themandibular tip and teeth via a groove. This chewing-tobaccolike substance isalso used in defense, and anyone who has collected tiger beetles with a light-colored net bag soon has a mesh with brown spots. A collector who is unluckyenough to have a larger tiger beetle mandible break the skin of his or herthumb also knows the sting of this uid.

    The larvae are peculiar among beetles. They all are designed for life in anarrow burrow. As a result, even though the adults may be nocturnal or di-urnal, long and thin or short and wide, the larvae are white and grublike(g. 2.1), with much of the outer covering of their bodies membranous. Adarkened armored capsule covers the head, and scattered dark plates are es-pecially noticeable on the top of the thorax (pronotum). They have a largehead with up to six small eyes on top and formidable mandibles underneath.A particularly striking feature is on the larvas lower back, which includes aprominent hump with two pairs of large hooks that face forward.

    The larvae, like adult tiger beetles, are carnivorous, but unlike the adults,the larvae wait for prey to come to them. Each larva positions itself at the topof a long burrow with its head and thorax ush to the substrate surface, exactly

    Tiger Beetles of the United States and Canada

    8

    Figure 2.1 Side view of tiger beetle larva at themouth of its burrow.

  • lling the diameter of the burrow entrance. Larval burrows, depending on thespecies, can be on at soil, vertical clay banks, forest leaf litter, or, for a fewtropical taxa, even in rotted wood of branches and twigs. When a prey itemcomes close to the burrow entrance, the larva extends its body, anchored by theback hooks in the side of the tunnel, and quickly reaches out backward to grabthe prey in its powerful mandibles. The larva then pulls the struggling preydown into the depths of its burrow and dispatches it with a few mighty bites.

    Because the head and thorax are usually the same color and texture asthe surrounding soil surface, most larvae are hard to see as they wait at the topof the burrows (g. 2.2). Their reaction to danger is to retreat immediatelyaway from the mouth of their burrows; thus their presence is made obviousonly when a black hole suddenly appears where before there was none.

    Body Parts

    Our keys for identifying tiger beetle species use simple language and are illus-trated wherever possible. However, identication requires some basic knowl-edge of anatomy, and we include here a simple overview of adult and larvalstructural features. These illustrations and brief explanations serve best as areference or kind of dictionary for translating otherwise arcane terms.

    Adults

    The hard, armorlike skin (cuticle) that covers the adult tiger beetle is criticalfor survival, but it is also useful in identication. The outermost layer (epi-cuticle) has patterns of tiny pits, larger punctures, ridges, and undulationscalled microsculpture. The differences in these patterns of microsculpture arefrequently used to distinguish tiger beetle species and genera. The cuticle islaminated with layers of melanin pigment and translucent waxes that alter-

    Recognizing Tiger Beetles

    9

    Figure 2.2 Photograph ofhead of larval Common Clay-bank Tiger Beetle (C. limbalis)at the mouth of its burrow.Photo by C. R. Brown.

  • nately reect and pass light. The distance between these alternating layersproduces a broad range of metallic colors through reectance and interfer-ence. The degree of uniformity of the cuticular reector determines the purityof reected color. Highly sculptured and nonuniform reectors produce abroad blend of colors of different wavelengths reected at various angles fromdifferent locations. This type of integument gives rise to dull green or browncolors similar to those made by pigments in other insects. In bright iridescentspecies, the cuticular sublayers are more uniform, and the surface is relativelysmooth. In all-black species, like those of the genera of Night-stalking TigerBeetles (Omus) and Giant Tiger Beetles (Amblycheila), the melanin is depositedin relatively thick and disorganized patterns that absorb most light. In otherspecies, parts of the integument have no pigment deposited, and these areasare pale yellow or white.

    The most frequently studied anatomical features of adult tiger beetles include the head (g. 2.3), where the distinctive characters include long,threadlike (liform) antennae with 11 segments (color, distribution of hairlikesetae, relative overall length) used primarily as tactile sense organs; mandibles(relative length, number, and position of teeth) used for capturing and pro-cessing prey and in males for grasping females during mating; upper lip orlabrum (color, length-width ratio, number and position of teeth, numberand position of setae) used with the mandibles to help grasp and process prey;

    Tiger Beetles of the United States and Canada

    10

    Figure 2.3 Head of typical adult tiger beetle and structures often used foridentication.

  • labium (presence and position of setae, relative length and color of the seg-ments of its ngerlike palpi); and maxillae (relative length and color of thesegments of its ngerlike palpi) used to manipulate and analyze the quality offood items. Other important parts of the head include the compound eyes(degree of bulging, relative size), the complexity of surface microsculpturingand depth of grooves (rugae) between the eyes and other parts of the head aswell as the distribution of white, hairlike, or thick and attened setae that mayfunction as sense organs and/or insulation against hot surfaces.

    Various adult eye sizes and shapes produce variable areas of stereoscopic(three-dimensional) vision. Nocturnal adults such as those of Giant TigerBeetles, Night-stalking Tiger Beetles, and Big-headed Tiger Beetles have small,relatively at eyes compared to the bulbous eyes of genera active during thelight of day.

    On the thorax (g. 2.4), the most frequent distinctions are found in theproportions of the thorax (rectangular, square, or elongate), its shape as viewedfrom above (cylindrical, parallel, rounded, trapezoid, and so on), the texture

    Recognizing Tiger Beetles

    11

    Figure 2.4 Top view of typical adult tiger beetle body and structuresoften used for identication.

  • (shiny metallic or dull) and color of the upper surface (pronotum), and thepatterns or absence of setae on its side, lower, or upper surfaces.

    In back of the pronotum (g. 2.4), the hardened elytra (modied frontwings) that cover the ight (hind) wings and top of the abdomen are the mostobvious characters. These elytra are spread and rotated forward in ight,where they may function as airfoils but do not ap. The elytral surface textureor microsculpturing can include large individual punctures (foveae), patternsof small pits (punctation), grooves (rugae), smooth (impunctate) areas, or un-dulations and tiny sawlike teeth (microserrations) and spines on the rear edgeof the elytra. Also important is the shape of the elytra from above (parallel-sided, rounded, oval, and the like), their prole as viewed from the side(domed, attened), their dark background color and texture (shiny metallic,dull), and the pattern, color, and position of spots, lines, and stripes (macu-lations) or their absence (immaculate). The ight wings are membranous,with a distinctive framework of thickened ridges called veins. Modicationsof tiny structures allow for a triple folding so that the ight wings can be re-

    Tiger Beetles of the United States and Canada

    12

    Figure 2.5 Front leg of typicaladult tiger beetle and structuresoften used for identication.

  • tracted completely under the elytra. In some ightless species, these ightwings are shrunk or even totally absent and with permanently fused elytra.

    The prominent legs (g. 2.5) of tiger beetles are thin and long for fastrunning. Leg color, positions of setae, and relative size (both to the overall sizeof the tiger beetle as well as to other segments on the same leg) are sometimesimportant as identifying characters. Males of all species have white pads oflong, curved setae on the feet (tarsi) of the front legs.

    The structure of the reproductive system in tiger beetles is well knownand has been used extensively in taxonomic comparisons. The extensible penis(g. 2.6) is located within a hardened (sclerotized) sheath called the aedeagus.The general shape of the aedeagus, the form of its tip, and the shape and po-sition of the sclerotized rings and internal elements are distinctive for manyspecies and give clues not only to species identication but also to phylo-genetic relationships among species. When the aedeagus is not extended, it ismaintained internally with the right-side down. Upon extension it rotates 90clockwise. At the tip of the extended aedeagus there is a less sclerotized area(internal sac). This internal sac is everted in copulation to extend beyond thetip of the hard aedeagus, and it delivers sperm to the female.

    The female reproductive system (g. 2.7) also includes some specializedcharacters. The eighth and ninth abdominal segments are modied to form atelescopic ovipositor, which is used to insert eggs, one at a time, into the sub-strate. Species differ considerably in the form and shape of the ovipositor, es-pecially the terminal portion (stylus). The differences in these characters haveonly begun to be studied but offer the potential for many insights into phy-logeny, ecology, and behavior.

    Recognizing Tiger Beetles

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    Figure 2.6 External male reproductive system.

    Figure 2.7 External femalereproductive system.

  • Larvae

    Larval tiger beetles have fewer characters (g. 2.8) that distinguish speciesthan do the adults. Important distinctions among larvae are found in theshape and relative size of the inner and median hooks on the back of the fthabdominal segment. The relative size, number, and placement of the simpleeyes (stemmata) and the relative lengths of the segments of the short anten-nae are often useful taxonomically. The size and shape and the presence ofridges on the head and dorsal thoracic plates (nota), mouthparts, and termi-nal abdominal segment (pygopod) can distinguish taxa. Also, sometimes im-portant are subtle differences in the number and position of hairlike setaethroughout the body.

    The eyes are the most studied organs of larval tiger beetles. The seden-tary larvae have less difculty detecting prey movement than do the mobileadults. Unlike the grublike larvae of some insects, which only can achieve acoarse visual pattern with their simple eyes, the eyes of tiger beetle larvae havedense photoreceptors that permit detailed focusing and three-dimensionalperception.

    Tiger Beetles of the United States and Canada

    14

    Figure 2.8 Side view of typical larval tiger beetle and structures oftenused for identication.

  • Tiger beetle biology, distribution, and natural history are connected by stud-ies of evolutionary relationships (phylogeny). Phylogenies are also importantfor a practical reason. Instead of randomly arranging tiger beetles in groups,the large number of species conveniently can be organized and categorized onthe basis of their relatedness, and these groups can be given names (taxon-omy). With an evolutionary basis that can be constantly tested and updated,everyone can communicate efciently about the organisms by using a reliableand relatively uniform system of names (nomenclature) to discuss a genus,species, or population.

    In 1915, Walther Horn developed a phylogeny and classication systemfor the then-known species of tiger beetles that continues to be used today.After Horn, the most signicant advance in our understanding of cicindelidclassication was made by Emilie Rivalier. He took advantage of the recogni-tion that in beetles and other insects the shape and structure of male genitaliaoften provide a unique character system for grouping closely related species.In a series of remarkable papers in the Revue Franaise dEntomologie, Rivaliermeticulously investigated the genitalia of most species of Cicindela on a world-wide basis, presenting one major biogeographic region in each paper. Basedon these investigations he designed a classication scheme for all majorgroups and dened more than 50 groups based on similarities in male geni-talia. This system, in which Rivalier attempted to group species based on sim-ilarity presumably reecting evolutionary relationships, as well as based ontheir biogeographic ranges for practicality, found wide acceptance and largelysuperseded the less explicit scheme of Horn.

    For North American taxa of tiger beetles, their names and evolutionarygroupings (clades) are generally stable, but as with all scientic endeavors,these classications are subject to reinterpretation and change as additional information becomes available. The genera of Giant Tiger Beetles (Ambly-cheila) and Night-stalking Tiger Beetles (Omus) form distinctive evolutionarygroups each considered generally to have been formed from a common an-cestor (monophyletic), although controversy surrounds how many speciesshould be recognized within the genus Omus. The genus of Big-headed TigerBeetles (Tetracha) is considered by some experts either to be a distinct genusor a subgenus within the worldwide genus Megacephala. Within the evolu-tionary branch of the Common Tiger Beetles (Cicindela), however, the greatest

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    3Phylogeny and Taxonomy

  • controversy continues. Should Rivaliers subgroups be considered subgenerawithin the genus Cicindela, or should the groups represent genera of theirown? Compared to debates surrounding other groups of animals and plants,these are relatively mild controversies, and they are basically differences ofopinion about which name should apply, not a question of whether the groupsthemselves are valid as distinct evolutionary branches.

    Modern studies of DNA, molecular clocks, sophisticated statistical pro-grams, and more intense eld collecting and observations will eventually helpgive us a better idea of the phylogeny and classication of tiger beetles. AlfriedVogler and colleagues at his molecular laboratory in London are at the fore-front of these intriguing new studies of tiger beetle evolution and phylogeny.Insight from his investigations of mitochondrial nucleotides will undoubtedlyregroup some species and switch other species from one subgenus to another.The groupings of species we use in this eld guide are only a convenience forcommunication and but one step closer to understanding the actual evolu-tionary process that resulted in the tiger beetles we see today.

    What Are Species?

    Although most biologists agree that plants and animals are made up of dis-creet groups of similar organisms we call species, how these species are dis-tinguished and which ones are different enough to have separate names areoften difcult and sometimes controversial decisions. In an admittedly over-simplied explanation, the evolution of species is an ongoing and dynamicprocess. At any one time, there are examples of many levels of how differ-ently two populations have become in terms of their genes, ecology, beha-vior, and physical appearance. At what point these differences are sufcientto distinguish them as separate species is usually in the eye of the beholder.There are also many denitions of what constitutes a species, but even ex-perts using the same denition cannot always agree what body structures,behavior, or molecules are the best ones on which to base such a decision.Because naming a species involves so many gray areas, we have used themost widely accepted decisions of tiger beetle experts published in journals.These decisions have been based on distribution data, studies of body struc-tures, and now, more and more frequently, on DNA and other molecularclues. However, we also recognize that each of these species decisions is a hy-pothesis based on the most current information. As more details and analyt-ical techniques become available, some of the named species will be splitor lumped with a new more insightful hypothesis replacing the old one.

    Tiger Beetles of the United States and Canada

    16

  • This is the power of critical thinking and the scientic method, even thoughit often frustrates those who would prefer nal and concrete names for thespecies they are studying.

    What Are Subspecies?

    Another aspect of phylogeny involves understanding patterns of differencesand similarities among individuals within the same species. Many, if not most,species show some differences across their geographical ranges. Usually thelarger the range the more likely there are to be differences in body size, color,and genes associated with geographical locations. Classically, these differentidentiable subsets of a species have been called races or subspecies. ErnstMayr called a subspecies a geographically dened aggregate of local popula-tions which differ taxonomically from other subdivisions of the species. Morerecently, others have argued that subspecies identication should be based ongenetic traits. Because different subspecies usually can interbreed freely andexchange genes, their status as a distinctive evolutionary group is vague andsubject to considerable change over a relatively short time. Where ranges ofdifferent subspecies meet, zones of intergradation often are found, in whichcolors or other distinguishing characters are intermediate or thoroughly mixed.These zones attest to an extreme plasticity of form and shape. If the subspeciesconcept is to be of any use, it needs to be dened as sharply as possible. Oneset of formal criteria for subspecies classication suggests that members of asubspecies share: (1) a unique geographic range or habitat; (2) several distinctsets of characters, all of which vary together across the range; and (3) a uniquenatural history relative to other subdivisions of the species.

    To formalize what is often an arbitrary geographical distinction, taxono-mists add a third name to the scientic name as a convenient shorthand to in-dicate the identication of a subspecies. This additional name also provides ameans of quickly communicating to others more precisely what organisms areunder review. The named subspecies, as well, often become more interestingto many people, and the patterns of geographical variation more focused. Forconservation efforts, subspecies names formalize distinct variations within aspecies that can make policy decisions more palatable to politicians and leg-islators. The key to using subspecies, however, is to never forget how impre-cise they are. It is within this context of more targeted patterns of geographi-cal variation and improved communication tempered by caution for anadmittedly vague concept that we include subspecies in the treatment of thetiger beetle fauna of the United States and Canada.

    Phylogeny and Taxonomy

    17

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  • Diagnostic Characters for Identication

    The extensive series of color plates in this eld guide includes species, sub-species, and additional variations of the U.S. and Canadian tiger beetles andshould enable both amateur and specialist to identify nearly all of the tigerbeetles they nd, especially when combined with the range maps and descrip-tive information in the species accounts. However, some species are very sim-ilar in color and marking patterns, and in these cases, the use of a taxonomickey which includes more detailed diagnostic characters may be needed. Thekeys that we use here are based on those developed by Harold Willis and GaryDunn, but we incorporate some reorganization and modications that shouldmake it easier to distinguish among the species. We also substitute less tech-nical terminology to make the key more user friendly for the nonspecialist.The diagnostic characters are described below and illustrated by line drawingsthroughout the key. In several cases, we also rely on diagnostic geographic dis-tribution to separate otherwise similar species. Be aware, however, that a fewspecies, especially those within the same couplet, may be especially difcultto separate because of the considerable amount of individual variation andoverlap in elytral maculations and other characters.

    Elytra and Color

    The elytra are the rst pair of hardened wings that cover the abdomen ofbeetles, and they are one of the most useful identifying characters. Their colorand often distinctive markings (maculations) readily identify many tiger beetles,especially when combined with habitat and geographic range. Elytral colorsare usually consistent within a species, but several distinct color forms mayoccur within a population or species. The color of the underside of the ab-domen is usually metallic, but in many of the American Tiger Beetles (sub-genus Cicindelidia) it is distinctly red or red-orange. The most common pat-tern of lines on the elytra includes three distinct white marks on each elytron(the complete or normal pattern), a front maculation (humeral lunule), amiddle maculation (middle band), and a rear maculation (apical lunule) at thetip (g. 4.1). In some tiger beetles these maculations are reduced to a series ofseparate dots (g. 4.1), some or all may be absent (immaculate), or, at the

    19

    4Illustrated Keys to AdultGenera and Species

  • other extreme, they can be greatly expanded and fused together to form mostlywhite elytra. The white line running along the outer edge of the elytra (mar-ginal line) may partially or fully connect the three maculations. Within spe-cies, subspecies, and populations there can be considerable variation in theextent of these maculations.

    The elytral surface may be shiny, metallic, dull, or greasy in appearance.These differences are caused by texture, primarily surface pits of variable size(seen under 40 magnication). Deep pits will give a shiny appearance,whereas shallow pits or no pits will make the elytra appear dull. Sometimeslarger pits, called punctures, are present, usually in rows on the front part ofthe elytra. These pits often reect a different color than the rest of the elytralsurface. Another variation of surface texture is the presence of small, raisedbumps or granules. Small toothlike projections (microserrations), seen only at40 magnication, are present along the rear margin of the elytra in somespecies. Distinct extensions or anges on the outer edge of the elytra are seenin females of a few species.

    Setae

    The numbers and types of hairlike setae on various parts of the body are use-ful in distinguishing species and some of the subgenera. Long, thin setae areoften present on the antennae, head, labrum, and at the base of the legs(trochanters). Most species have a row of long sensory setae along the outerend of the rst antennal segment (see g. 4.24), but may or may not have ad-ditional setae on other parts of the segment. Groups of long, erect setae thatoriginate from medium or large pits are especially common in most species inthe Temperate (subgenus Cicindela), American (subgenus Cicindelidia), and

    Tiger Beetles of the United States and Canada

    20

    Figure 4.1 Left elytron showingnormal pattern of markings andfrequently used identifyingcharacters; right elytron showingreduced markings pattern.

  • Rounded-thorax (subgenus Cylindera) tiger beetles. These setae may be wornoff in older specimens, but evidence of their presence can often be deducedfrom the presence of these peculiar pits. Short, thick, attened setae on thehead and thorax are diagnostic for most species of the Habro (subgenusHabroscelimorpha), Ellipsed-winged (subgenus Ellipsoptera), and Eunot (sub-genus Eunota) tiger beetles.

    Other Characters

    The proportional length and the number of teeth (usually one or three) on thelabrum are also used in the key. Usually the labrum is wide and short, but ina few species it is longer than it is wide. Body length varies from about 6 mmto more than 30 mm and may be used to separate some of the species, par-ticularly the small species, which are 69 mm in body length.

    Identication Keys

    The rst key below is to adults of the four genera found in the United Statesand Canada: Giant Tiger Beetles (Amblycheila), Night-stalking Tiger Beetles(Omus), Big-headed Tiger Beetles (Tetracha), and Common Tiger Beetles (Ci-cindela). Subsequent keys identify species within each genus. For the genusCicindela, a few variable species key-out at more than one place because thereare several distinct subspecies.

    Key to the Genera

    1a Front corners of pronotum without a forward Common Tiger Beetlesprojecting lobe (g. 4.2B) (Cicindela)

    1b Front corners of pronotum prominent with a distinct projecting lobe (g. 4.2A) 2

    Keys to Adult Genera and Species

    21

    Figure 4.2 A, prominent front corner of pronotum ofTetracha; B, lack of front corner of pronotum of Cicindela.

  • 2a Upper parts metallic colored with yellowish legs, Big-headed Tiger Beetles antennae and mouth parts (Tetracha)

    2b Upper parts black or dark brown with dark legs, antennae and mouth parts 3

    3a More than 20 mm in length Giant Tiger Beetles (Amblycheila)

    3b Less than 20 mm in length Night-stalking Tiger Beetles (Omus)

    Key to the Species of Giant Tiger Beetles (Amblycheila)

    1a Large body size (2936 mm), found east ofRocky Mountains 2

    1b Smaller body size (2028 mm), west ofRocky Mountains 3

    2a Single row of pits between the two inner South Texas Giant Tigerpleats on elytra; south Texas only Beetle (A. hoversoni)

    2b Entire elytral surface covered with rows of pits; Great Plains Giant Tiger not found in south Texas Beetle (A. cylindriformis)

    3a Dull black elytral surface, with a single ridge or Montane Giantpleat (rarely two) running the length of each TigerBeetleelytron (g. 4.3A); central and southeastern (A. baroni)Arizona (perhaps extreme west Texas)

    3b Black but shiny and with three pleats running the length of each elytron; not found in southeastern 4Arizona (g. 4.3B)

    4a Occurs in intermontane valleys of southern Rocky Mojave Giant Tiger Mountains of southwest Utah to California Beetle (A. schwarzi)

    4b Occurs in southwest Colorado, northern Plateau Giant Tiger New Mexico to central Arizona Beetle (A. picolominii)

    Tiger Beetles of the United States and Canada

    22

    Figure 4.3 A, one pleat running the length of elytron(Montane Giant Tiger Beetle, A. baroni ); B, three pleatsrunning the length of each elytron (Mojave Giant TigerBeetle, A. schwarzi ).

  • Key to the Species of Night-stalking Tiger Beetles (Omus)

    1a Large (1820 mm), dull black with small dimples Greater Night-stalking scattered across the elytra Tiger Beetle (O. dejeanii)

    1b Smaller in size, shiny black with smooth granular elytral surface 2

    2a Distinct row of long, stout, black hairs on upper side Lustrous Night-stalking of thorax; range restricted to border of Fresno and Tiger Beetle Monterrey Counties in central California (g. 4.4) (O.submetallicus)

    2b No setae on upper side of thorax 3

    3a Surface of pronotum with distinct furrows and California Night-stalkingridges; thorax with forward corners extending Tiger Beetledownward to just below level of the eye; elytra (O. californicus)distinctly domed in prole (g. 4.5A)

    3b Surface of pronotum relatively smooth; thorax with forward corners extending downward to well below 4the level of the eye; elytra slightly domed (g. 4.5B)

    4a Moderately shiny black, pitted areas of elytra Audouins Night-stalkingsurface arranged in irregular pattern Tiger Beetle

    (O. audouini)

    4b Shiny, pitted areas of elytral surface arranged in Mount Ashland Night- regular pattern; restricted to Mount Ashland in stalking Tiger Beetle southwestern Oregon (O. cazieri)

    Keys to Adult Genera and Species

    23

    Figure 4.4 Top view of thorax and head of Lustrous Night-stalking Tiger Beetle(O. submetallicus) showing unique blackhairs along sides of pronotum.

    Figure 4.5 A, top of thorax with forwardcorners slightly turned down (CaliforniaNight-stalking Tiger Beetle, O. californicus);B, forward corners turned distinctly down(Audouins Night-stalking Tiger Beetle,O. audouini ).

  • Key to the Species of Big-headed Tiger Beetles (Tetracha)

    1a Elytra dark, oily green without light-colored Virginia Big-headed Tiger maculations Beetle (T. virginica)

    1b Elytra bright maroon or dark green with light-colored maculations at rear tip 2

    2a Rear maculations not expanded at their front ends Upland Big-headed Tiger Beetle (T. afnis)

    2b Rear maculations crescent-shaped and distinctly Pan-Americanexpanded at their front ends Big-headed Tiger Beetle

    (T. carolina)

    Key to the Species of Common Tiger Beetles (Cicindela)

    1a Front trochanters with one (rarely two) subapical setae, middle trochanters with or without such setae 15(g. 4.6A)

    1b Front trochanters without subapical setae, middle trochanters also without such setae (g. 4.6B) 2

    2a Femora of hind legs long, extending for more than one-third of their length beyond end of body 3

    2b Femora of hind legs short, typically not extending more than one-third of their length beyond end 4of body

    3a Underside of thorax (prosternum) with dense, Eastern Beach Tiger attened setae (g. 4.7) Beetle (C. dorsalis)

    3b Underside of thorax (prosternum) without setae; Lime-headedknown only from old records on far south Tiger BeetleTexas coast (C. chlorocephala)

    4a Abdominal segments green with some brown (Louisiana to west Texas) or last few segments Ocellated Tiger Beetleall brown (New Mexico and Arizona); maculations (C. ocellata)consisting of a series of four nearly equally separated dots

    Tiger Beetles of the United States and Canada

    24

    Figure 4.6 A, trochanter of middle legwith seta; B, trochanter with no seta.

    Figure 4.7 Dense, attened setae onunderside of thorax (Eastern Beach TigerBeetle, C. dorsalis).

  • 4b Abdominal segments orange, orange-red or rarely brown; maculations not as above 5

    5a Elytra green to green-brown with a wide, Cobblestone Tiger Beetlelight-colored border along the outer edge (C. marginipennis)

    5b Elytra without above combination of characters, usually black to brown, rarely green 6

    6a Elytra dull black with wide maculations, including Schaupps Tiger Beetlea wide, straight middle maculation that angles (C. schauppii)back away from the outer edge

    6b Elytra dull or shiny, black to brown or sometimes blue, without wide or angled maculations 7

    7a Elytra with three orangish maculations; accidental Red-lined Tigeron the border of southern Arizona and Beetle (C. fera)New Mexico

    7b Maculations whitish and thin or reduced 8

    8a Labrum with 4 setae (g. 4.8A,C) 9

    8b Labrum with 6 setae (g. 4.8E) 10

    9a Sides of underparts of thorax and abdomen Eastern Pinebarrens sparsely covered with attened setae; pronotum Tiger Beetlewith some setae; northern Florida to New York (C. abdominalis)(g. 4.8B)

    9b No setae on underparts of abdomen or on Highlands Tiger Beetlepronotum; restricted to Polk and Highlands (C. highlandensis)counties in central Florida (g. 4.8D)

    10a Elytral surface with deep pits (g. 4.8F) and shiny surface; many setae on sides of abdomen and Scabrous Tiger Beetle thorax; small (< 9 mm); restricted to Florida (C. scabrosa)Peninsula

    10b Elytral surface variable, larger in size (> 8 mm); not found in Florida Peninsula 11

    11a Elytra with two parallel rows of shallow, green Caziers Tiger Beetlepits (punctures) along inner edge of each elytron, (C. cazieri)restricted to Rio Grande Valley of south Texas

    Keys to Adult Genera and Species

    25

    Figure 4.8 A and C, labra with four setae; E, labrum with six setae; B, sides of thoraxand abdomen with sparse setae (Eastern Pine Barrens Tiger Beetle, C. abdominalis);D, sides of thorax and abdomen with nosetae (Highlands Tiger Beetle, C. highland-ensis); F, sides of thorax and abdomen withdense setae and upper surface of elytra withdeep pits (Scabrous Tiger Beetle, C. scabrosa).

  • 11b Elytra without shallow, green pits (punctures); wider ranging 12

    12a Elytral surface shiny, variable colors, maculations Limestone Tiger Beetleabsent, reduced or limited to outer portion (C. politula)of elytra

    12b Elytral surface not shiny, maculations variable 13

    13a Maculations reduced to thin lines and spots; Eastern Red-bellied Tiger south Texas to Massachusetts Beetle (C. ruventris)

    13b Usually with distinct middle maculation; from west Texas west 14

    14a Middle maculation slightly constricted in middle Wetsalts Tiger Beetle(g. 4.9A); elytra of female and male expanded (C. hemorrhagica)in middle

    14b Middle maculation strongly constricted in middle Western Red-bellied (g. 4.9B); elytra of female not expanded; Tiger Beetleelytra of male widened in rear one-fourth (C. sedecimpunctata)

    15a Very small (10 mm); trochanters of middle legs with one or rarely two long setae (g. 4.6A) 18

    16a Metallic red; maculations consist of a longitudinal White-striped Tigerband running length of elytra near outer edge Beetle (C. lemniscata)

    16b Brown or red brown; maculations consist of dots or short stripes 17

    17a Elytra dark brown with distinct green punctures Pygmy Tiger Beetleand pits; underside of abdomen with sparse, (C. viridisctica)attened setae along outer edge

    17b Elytra red to coppery red without distinct Sonoran Tiger Beetlepunctures and pits; without dense, attened (C. wickhami)setae on underside of abdomen

    Tiger Beetles of the United States and Canada

    26

    Figure 4.9 A, middle maculation slightly constricted (WetsaltsTiger Beetle, C. hemorrhagica); B, elytron with middlemaculation strongly constricted (Western Red-bellied TigerBeetle, C. sedecimpunctata).

  • 18a Area of face above labrum (clypeus) densely to sparsely covered with attened setae (g. 4.10A) 19

    18b Area of face above labrum (clypeus) without setae or with only a few erect setae (g. 4.10B) 32

    19a Underside of thorax (prosternum) with dense, attened setae 20

    19b Underside of thorax (prosternum) without setae 24

    20a Elytral surface dull without pits; maculations diffuse and broadly expanded 21

    20b Elytral surface dull to shiny with many deep pits; maculations variable 22

    21a Labrum with few (20) at- Moustached Tiger Beetle tened setae; inner margins of white maculations (C. hiritlabris)more distinct; restricted to peninsular Florida

    22a Sides of pronotum distinctly convex; middle White-cloaked Tigermaculation not prominent; broad white band Beetle (C. togata)along outer edge of elytra or elytra entirely white

    22b Sides of pronotum straight or slightly curved; distinct middle maculation 23

    23a Rear end of female elytra bent downward at tips, apical spine slightly retracted (g. 4.11C); right Margined Tiger Beetlemandible of male with prominent tooth below; (C. marginata)Atlantic coast and south Florida Gulf coast (g. 4.11A)

    23b Rear end of female elytra not bent downward at tips, apical spine much retracted (g. 4.11 D); Coastal Tiger Beetleright mandible of male with bump or no tooth (C. hamata)below (g. 4.11B); Gulf coast, Florida to Texas

    24a Legs without pigment (pale tan); distinct cluster Ghost Tiger Beetleof setae on fourth antennal segment (C. lepida)

    24b Legs pigmented dark 25

    Keys to Adult Genera and Species

    27

    Figure 4.10 A, clypeus with dense, attenedsetae; B, clypeus with sparse or no setae.

  • 25a Front maculation with a prominent dot at front end of each elytron forming a G or inverted G 26(g. 4.12A, B)

    25b Front maculation without a basal dot at front end of each elytron forming a J or inverted J 30(g. 4.12C)

    26a Medium sized (>11 mm); middle maculation long 27

    26b Small (

  • 29a Elytra dull, pits smaller and more shallow; tip endsof the female elytra pointed, often with a small Sandy Stream Tigernotch between them; rear end of middle Beetle (C. macra)maculation recurved

    29b Elytra shiny, pits larger and deeper; tips of the Coppery Tiger Beetleelytra of female rounded with no notch; rear end (C. cuprascens)of middle maculation globular

    30a First antennal segment with few to many setae in addition to sensory setae (g. 4.13A); Nevada Tiger Beetlemiddle maculationusually hooked at the rear (C. nevadica)and only slightly S-shaped

    30b First antennal segment with only long sensory setae and no small setae (g. 4.13B); middle 31maculation usually not hooked at the rear and not S-shaped

    31a Sides of thorax coppery; elytral surface dull brown Rio Grande Tiger Beetle to reddish brown (C. sperata)

    31b Sides of thorax blue-green to blue-purple Aridland Tiger Beetle(may be coppery at upper edge); elytral surface (C. marutha)shiny green or reddish brown

    32a Area of forehead between eyes (frons) without setae (except for 12 along inner edge of each eye) or with a cluster of attened setae above 33

    the antennae

    32b Area of forehead between eyes (frons) with erect setae 65

    33a Area of forehead between eyes (frons) with small clusters of attened setae above antennae Gulfshore Tiger Beetle(g. 4.14A); restricted to Gulf coast of Texas, (C. pamphila)rarely Louisiana or Mississippi

    33b Area of forehead between eyes (frons) without setae (except for one or two along inner edge of 34eye) (g.4.14B)

    Keys to Adult Genera and Species

    29

    Figure 4.13 A, rst antennal segment with small setae in addition to long sensory setae (Nevada Tiger Beetle, C. nevadica); B, rst antennal segment with only two longsensory setae (Rio Grande Tiger Beetle, C. sperata).

  • 34a Legs covered throughout with ne, attened setae; head proportionally large; body and legs all black 35with no maculations

    34b Legs covered incompletely or sparsely with setae, but not clothed throughout; body and legs not 36black and maculations variable

    35a Elytral surface with deep, distinct punctures, never with green reections in punctures; elytra dull, Loamy-ground Tigernot velvetlike in appearance; male labrum black Beetle (C. belfragei)with light-colored patch in center, Texas to extreme southern Oklahoma

    35b Elytra surface with ne, uniformly spaced, shallow punctures, never with green reections in punctures; elytra velvetlike in appearance; pruinina formmale labrum black with light-colored patch in center

    35c Elytra with few scattered, shallow punctures with green reections; elytra velvetlike in appearance; Cajun Tiger Beetlemale labrum entirely white or straw colored; (C. pilatei)Louisiana to eastern Texas

    35d Elytra with no punctures, elytra strongly velvetlike in appearance; male labrum entirely black and Velvet Tiger Beetleoften with faint dark-green metallic luster; (C. velutinigrens)south Texas

    36a Small (< 9 mm), dark brown beetles; prothorax cylindrical with nearly straight sides 37

    36b Without above combination of characters 38

    37a Elytra notably expanded in posterior one-half; maculations usually reduced, without incomplete Swift Tiger Beetle whitish line or no line along the outer edge (C. celeripes)(g. 4.15)

    37b Elytra not notably expanded in posterior one-half; Ant-like Tiger Beetleusually with complete whitish line along outer (C. cursitans)edge (g. 4.16)

    38a Side of thorax (proepisternum) with setae (occasionally only a few near base of leg) 39

    38b Side of thorax (proepisternum) without setae 40

    Tiger Beetles of the United States and Canada

    30

    Figure 4.14 A, frons with clusters of setae neareach eye (Gulfshore Tiger Beetle, C. pamphila);B, frons with no clusters of setae.

  • 39a Labrum medium or short 41

    39b Labrum longer than wide 48

    40a Large (>12 mm), brown with single white spot One-spotted Tiger Beetleat middle of outer edge of elytra; labrum long, (C. unipunctata)not found in southwestern United States

    40b Small (

  • 43a Elytral surface dull; middle tooth of labrum shorter Autumn Tiger Beetlethan teeth on either side of it; male with a black (C. nigrior)labrum with two white spots; active only in the fall

    43b Elytral surface shiny; middle tooth of labrum not Festive Tiger Beetleshorter than other two; male with all white labrum; (C. scutellaris)active both fall and spring

    44a First antennal segment with 1 (rarely 2) seta 45

    44b First antennal segment with 24 setae Black Sky Tiger Beetle(C. nigrocoerulea)

    45a Sides of abdomen with no setae Horns Tiger Beetle(C. hornii)

    45b Sides of abdomen with few to sparse attened setae 46

    46a Pronotum without setae; elytra shiny with distinct Elusive Tiger Beetlepits along inner edges; Florida to South Carolina (C. striga)

    46b Pronotum with at least some setae along outer edge; elytra rarely shiny; with shallow or no pits; 47central to western species

    47a Large, robust species (>15 mm); rear half of elytra Large Grassland Tiger without punctures or pits Beetle (C. obsoleta)

    47b Small species (

  • 52a Two or 3 (rarely 4) setae above eyes; central, Dispirited Tiger Beetlefront portion of middle maculation not concave (C. depressula)(if present) (g. 4.19A)

    52b Clusters of 811 setae above eyes; central, front Western Tiger Beetleportion of middle maculation concave (g. 4.19B) (C. oregona)

    53a Elytral surface dull; middle maculation usually Northern Barrens Tigercomplete; outer edge of abdomen with sparse Beetle (C. patruela)at setae

    53b Elytral surface shiny, with shallow to deep pits; outer edge of abdomen without setae; middle 54maculation usually broken into dots or absent

    54a Green to olive green above; restricted to south- Laurentian Tiger Beetleeastern Manitoba, northern Minnesota, and (C. denikei)southwestern Ontario (1315 mm)

    54b Bright metallic green (rarely purple) above; Six-spotted Tiger Beetlethroughout most of eastern United States, (C. sexguttata)southeastern Canada (1014 mm)

    55a Maculations incomplete, broken into dots or absent 56

    55b Maculations complete, often fused 58

    Keys to Adult Genera and Species

    33

    Figure 4.18 A, labrum with three teeth (Saltmarsh TigerBeetle, C. severa); B, labrum with one tooth (PuncturedTiger Beetle, C. punctulata).

    Figure 4.19 A, typical middle maculation of Dispirited TigerBeetle (C. depressula); B, typical middle maculation ofWestern Tiger Beetle (C. oregona).

  • 56a Labrum with 810 setae S-banded Tiger Beetle(C. trifasciata)

    56b Labrum with fewer than 8 setae 57

    57a Labrum with 1 tooth (Fig 4.18B) Punctured Tiger Beetle(C. punctulata)

    57b Labrum with 3 teeth (g. 4.18A) Saltmarsh Tiger Beetle(C. severa)

    58a Middle maculation short, diagonal or represented by a bulge 59

    58b Middle maculation normal, very long and slender, or diagonal and long 62

    59a Cheeks (genae) with sparse, attened setae Riparian Tiger Beetle(g. 4.20) (C. praetextata)

    59b Cheeks (genae) without setae 60

    60a Middle maculation a sharp or rounded bulge, Cream-edged Tiger only slightly lengthened toward the rear (g. 4.21) Beetle (C. circumpicta)

    60b Middle maculation more lengthened toward the rear or fused (g. 4.22) 61

    61a Found in New Mexico, western Texas, eastern Glittering Tiger BeetleArizona and extreme northeastern Chihuahua, (C. fulgoris)Mexico

    Tiger Beetles of the United States and Canada

    34

    Figure 4.20 Flattened hairlike setae on sides of face (genae)(Riparian Tiger Beetle, C. praetextata).

    Figure 4.21 Middle maculation reduced to rounded bulgewith little (A) or no (B) extension to the rear (Cream-edgedTiger Beetle, C. circumpicta).

  • 61b Found in California and coastal northwestern California Tiger BeetleMexico (C. californica)

    62a Underside of thorax (prosternum) with a few erect Western Tidal Flatsetae, rear maculation extends far forward, parallel- Tiger Beetle ing outer edge of elytron (occasionally reduced); (C. gabbii)restricted to southern California coast

    62b Underside of thorax (prosternum) without setae, rear maculation normal 63

    63a Middle maculation elaborate and S-shaped S-banded Tiger Beetle(g. 4.23A) (C. trifasciata)

    63b Middle maculation normal (g. 4.23B) 64

    64a Rear tip of abdomen red; restricted to Florida Keys Olive Tiger Beetle(C. olivacea)

    64b Rear tip of abdomen not red; found in south- Thin-lined Tiger Beetlewestern United States (g. 4.23) (C. tenuisignata)

    65a Cheeks (genae) with setae (g. 4.20), but occasionally only one or two at bottom 66

    65b Cheeks (genae) without setae 90

    Keys to Adult Genera and Species

    35

    Figure 4.22 A, typical macula-tion pattern of the CaliforniaTiger Beetle (C. californica), inwhich the dark wedge betweenthe middle and rear maculationsextends forward less or aboutthe same distance as rearward;B-D, range of maculation patternsfor the Glittering Tiger Beetle (C. fulgoris), in which the darkwedge between the middle andrear maculations, if present,extends farther forward thatrearward.

    Figure 4.23 A, strongly S-shaped middle maculation (S-banded Tiger Beetle C. trifasciata); B, more normal-shaped middle maculation.

  • 66a Labrum with 1 tooth or no teeth (g. 4.18B) 67

    66b Labrum with 3 teeth (g. 4.18A) 70

    67a First antennal segment with 45 long setae; sand dune habitat (g. 4.24B) 68

    67b First antennal segment with 3 long setae; variable habitats but usually riparian (g. 4.24A) 69

    68a Restricted to coastal sand dunes from northern Pacic Coast Tiger BeetleCalifornia to Washington (C. bellissima)

    68b Restricted to Coral Pink Sand Dunes in south- Coral Pink Sand Dune western Utah Tiger Beetle (C. albissima)

    68c Restricted to Great Sand Dunes, southern Colorado Dune Tiger Colorado Beetle (C. theatina)

    68d Restricted to Bruneau dune area of southwestern Bruneau Dune Idaho and shows distinct tooth on mandible Tiger Beetleprojecting upward (g. 4.25) (C. waynei)

    68e Restricted to St. Anthony dune area of central St. Anthony Dune Tigerand eastern Idaho Beetle (C. arenicola)

    68f Found in Great Plains of United States and Canada with isolated colonies in Labrador and Sandy Tiger Beetle

    northwestern Alaska (C. limbata)

    69a Front maculation usually complete and connected to or only slightly separated from white line along Bronzed Tiger Beetleouter edge of elytra; pronotum narrow with front (C. repanda)about the same width as back (proportions 4 units long to 5 wide) (g. 4.26A)

    69b Front maculation usually broken and widely sepa-rated from outer edge of elytra and white line Twelve-spottedalong this outer edge usually absent; pronotum Tiger Beetletrapezoidal in shape with front wider (proportions (C. duodecimguttata)4 units long to 6 wide) (g. 4.26B) than back

    70a Front maculation complete, or so broad it be-comes obscured by heavy side extension (front 71maculation extends almost to the middle of elytron)

    Tiger Beetles of the United States and Canada

    36

    Figure 4.24 A, rst antennal segment with three longsetae; B, rst antennal segment with four to ve longsetae.

  • 70b Front maculation absent, broken into dots, or if complete, projects only slightly toward middle 74

    71a Maculations connected along outer edge of elytra 72

    71b Maculations not connected along outer edge Oblique-lined Tiger of elytra Beetle (C. tranquebarica)

    72a Front maculation separate from middle maculation C. tranquebarica diffracta

    72b Front maculation connected to middle maculation along outer edge of elytra 73

    73a Labrum long (width/length ratio 15 mm long and proportionately stout (C. formosa)

    74a Middle maculation long, reaching back nearly to rear maculation; maculations not connected along 75outer edge of elytra

    74b Middle maculation short or absent; maculations often connected along outer edge of elytra 77

    75a Front maculation long, straight, and angling away Oblique-linedfrom the outer edge of the elytra (g. 4.27A) Tiger Beetleor absent (C. tranquebarica)

    75b Front maculation not as above 76

    Keys to Adult Genera and Species

    37

    Figure 4.25 Distinctive tooth on mandible of theBruneau Dune Tiger beetle (C. waynei) projectingupwards.

    Figure 4.26 A, cylindrical orsymmetrical thorax shape (BronzedTiger Beetle, C. repanda);B, trapezoidal thorax shape(Twelve-spotted Tiger Beetle, C. duodecimguttata).

  • 76a Elytra reddish-brown to dark greenish brown; all Appalachian Tiger Beetlemaculations thin but usually complete; eastern (C. ancocisconenesis)species

    76b Elytra purplish, red, green, or black; maculations variable but usually reduced and thick; front Badlands Tiger Beetlemaculation short or absent, often two dots (C. decemnotata)and projects only slightly toward the inner edge of the elyron; western species

    77a Maculations absent except for small rear one at Big Sand Tiger Beetletip of elytra; restricted to southeastern New subspecies (C. formosaMexico and far west Texas rutilovirescens)

    77b Maculations apparent; not present in New Mexico or far west Texas 78

    78a Head and pronotum much differently colored than elytra 79

    78b Head, pronotum, and elytra similarly colored (although there may be contrasting colors running 80along outer edge of elytra)

    79a Head and pronotum copper, elytra blue-green Cow Path Tiger Beetleor green (C. purpurea)

    79b Head and pronotum green to blue or blue-purple, Splendid Tiger Beetleelytra red to green-red (C. splendida)

    80a Middle maculation absent or reduced to a transverse dash (g. 4.28A) 81

    80b Middle maculation complete or consists of an angled, bent line (g. 4.28B) 85

    81a Sagebrush and alpine areas of California, Nevada, Alpine Tiger BeetleOregon, and Idaho; labrum of female black (C. plutonica)

    81b Restricted to Death Valley area of eastern Oblique-lined Tiger California; labrum of female whitish Beetle subspecies

    (C. tranquebarica arida)

    81c East of Rocky Mountains 82

    Tiger Beetles of the United States and Canada

    38

    Figure 4.27 A, long, straight front maculation angledaway from outer edge of elytron (Oblique-lined TigerBeetle, (C. tranquebarica); B, front maculation short and reduced to two dots (Badlands Tiger Beetle,C. decemnotata).

  • 82a Elytra black Cow Path Tiger Beetle(C. purpurea)

    82b Elytra not black 83

    83a Elytra green or blue-green 84

    83b Elytra reddish or dark red Common Claybank Tiger Beetle (C. limbalis)

    84a Northwestern Louisiana, southwestern Arkansas, Splendid Tiger Beetle and northeastern Texas form (C. splendida

    ludoviciana)

    84b Great Plains Green Claybank Tiger Beetle (C. denverensis)

    85a Maculations not connected along outer edge ofelytra 86

    85b Maculations connected along outer edge of elytra or middle maculation broadly expanded along 89outer edge of elytra

    86a Restricted to Santa Cruz County, California; front Ohlone Tiger Beetlemaculation reduced to one or two dots (C. ohlone)

    86b Not found in Santa Cruz County, California 87

    87a Middle maculation with only a slight or rounded Cow Path Tiger Beetlebend (g. 4.28C); front maculation absent (C. purpurea)

    87b Middle maculation with sharp bend (g. 4.28B); front maculation complete or broken into dots 88

    88a Head, pronotum, and elytra bright metallic green Green Claybank Tiger or blue; middle maculation usually reduced but Beetle (C. denverensis)may be complete

    88b Head, pronotum and elytra brick red or cuprous Common Claybank TigerBeetle (C. limbalis)

    Keys to Adult Genera and Species

    39

    Figure 4.28 A, middle maculation atransverse dash (Alpine Tiger Beetle, C. plutonica); B, middle maculation withsharp bend (Common Claybank TigerBeetle, C. limbalis); C, middle maculationwith rounded bend (Cow Path TigerBeetle, C.purpurea).

  • 89a Elytra dark green to dark red-green to black Cow Path Tiger Beetlesubspecies (C. purpurea

    cimarrona)

    89b Elytra bright red, bright red-green or bright green Common Claybank Tiger Beetle (C. limbalis)

    90a Underside of thorax (prosternum) with sparse, erect setae; maculations complete and heavy; Western Beach Tigerupper surface blackish; restricted to beaches of Beetle (C. latesignata)coastal southern California

    90b Without these characters 91

    91a Elytral surface smooth without pits or bumps Festive Tiger Beetle (C. scutellaris)

    91b Elytral surface uneven with small bumps, pits or granules 92

    92a First antennal segment with 02 long, erect setae in addition to small sensory setae 93

    92b First antennal segment with at least several long, erect setae in addition to small sensory setae 95

    93a First maculation present, long and angling away Pacic Coast Tiger from outer edges of elytra Beetle (C. bellissima)

    93b First maculation absent or, if present, not angling away from outer edges of elytra or obvious and 94projecting toward the front

    94a With many long setae on lower forehead (frons) Hairy-necked Tiger Beetle (C. hirticollis)

    94b Without setae on lower forehead (frons) but with Dispirited Tiger Beetleclusters of 24 setae above eyes (C. depressula)

    95a Labrum long (width/length ratio 1.9) 96

    96a Labrum with 1 tooth (or if with 3 apparent teeth, front maculation is short and C-shaped, or if front maculation is absent or reduced, rear of elytra with 97

    microserrations) (g. 4.18B)

    96b Labrum with 3 teeth (or if only 1 obvious tooth, front maculation long and angles away from outer 102edge of elytra) (g. 4.18A)

    97a Maculations reduced; rst antennal segment with 3, sometimes 4 long, sensory setae 98

    97b Maculations normal, conuent, or, if reduced, rst antennal segment with 5 long, sensory setae 100

    Tiger Beetles of the United States and Canada

    40

  • 98a Rear maculation absent; restricted to southeastern Cochise Tiger BeetleArizona (C. pimeriana)

    98b Characters not as above; only rear maculation present 99

    99a Elytral surface appears greasy with distinct pits; Willistons Tiger Beetlebody larger; more distinct microserrations; rear subspeciesmaculation smaller with front edge horizontal (C. willistoni praedicta)

    99b Elytral surface appears smooth with small, in-distinct pits; ner, less distinct microserrations; Great Basin Tiger Beetlerear maculation larger with front edge angled (C. amargosae)forwards toward inner edges of elytra

    100a Elytral surface dull (with many tiny pits between punctures) 101

    100b Elytral surface appears greasy with distinct pits Willistons Tiger Beetleand bumps (C. willistoni)

    101a Combined tarsal segments of hind leg as long as tibia; front maculation absent or if present not Senile Tiger Beetlereaching as far toward middle as bend of middle (C. senilis)maculation (g. 4.29A)

    101b Combined tarsal segments of hind leg shorter than Short-legged Tiger Beetletibia; front maculation reaching as far toward (C. tenuicincta)middle as bend of middle maculation (g. 4.29B)

    102a Maculations reduced, middle maculation absent Beautiful Tiger Beetleor reduced to a triangle; elytra reddish; large (C. pulchra)body size (>15 mm)

    102b Maculations normal or, if reduced, elytra not red; medium body size (

  • 104a Front maculation complete or at least with a dot Oblique-lined Tiger on shoulder Beetle (C. tranquebarica)

    104b Front maculation absent, no dot on shoulder 105

    105a Great Basin from Central Oregon to British Sagebrush Tiger BeetleColumbia; surface of elytra less shiny; labrum (C. pugetana)of female black

    105b Southeastern Oregon and northern California to Alpine Tiger BeetleUtah and western Montana; surface of elytra (C. plutonica)more shiny; labrum of female black

    105c Restricted to Death Valley area of eastern Oblique-lined Tiger California; labrum of female whitish Beetle subspecies

    (C. tranquebarica arida)

    Tiger Beetles of the United States and Canada

    42

  • The larval stages of tiger beetles have received much less interest and studythan adults, probably because of their burrow-dwelling habits and aestheti-cally less pleasing grublike appearance. Finding the burrows of larvae requiresexamination of the ground surface at close range (usually you have to hunchover a bit to see them), a very different technique from that of nding adults,where you need to be looking 520 meters ahead. Another problem is the dif-ficulty in identifying larvae to species. The characters used (especially numbersand arrangement of setae on the pronotum and other body parts and charac-teristics of the hooks on the fth abdominal segment) are often difcult to ndand less distinctive than most adult characters. Also, these characters maychange as the larvae advance through each of their three distinct growth stages(instars). This historic disregard for larvae is unfortunate because biologicallyand ecologically larvae often are more important than adults as habitat indi-cators and for evaluating the viability and dynamics of populations.

    Another problem with studying and identifying larvae is that only about60% (67 of 109) of the species from the United States and Canada are de-scribed, and some of the descriptions are incomplete. Most of these descrip-tions are of only the third instar, which is the basis of most larval taxonomy.Virtually no one has studied the differences among subspecies or variationwithin a species. There is no comprehensive key to the described larvae, andmost regions and habitats of Canada and the United States, especially in thewest, include many species for which the larvae have not been described. Afew regional keys to third instar larvae are available for small areas of theUnited States, but they are not useful for many areas of North America. De-spite these problems, larvae may often be identied with some certainty byusing other information, such as knowledge of the adults present in the larvalhabitat, the larval instar number, diameter of the larval burrow or of the lar-val pronotum, depth and microhabitat of the burrow, and peculiar construc-tion of the burrow.

    Because of this lack of information for many species of larvae, we cannotinclude descriptions or keys to this level. However, larval characteristics of thefour genera found in the United States and Canada are distinct (g. 5.1), andusing these characters, we provide a comparative description and a simple keyto the genera of tiger beetles of the region.

    43

    5Identication of Tiger Beetle Larvae

  • Comparative Descriptions

    Giant Tiger Beetles (Amblycheila): Second pair of simple eyes distinctly smallerthan rst pair; inner and median hooks on the fth abdominal hump are sim-ilar in shape, thornlike, and with numerous stout setae; inner and medianhooks are distinctly separated at their bases (g. 5.2A); fourth antennal seg-ment very small, less than one-fth the length of the third segment.

    Night-stalking Tiger Beetles (Omus): Second pair of simple eyes distinctlysmaller than rst pair; fth abdominal hump with three pairs of hooks: inner,median, and lateral hooks; median pair longer than the other two (g. 5.2B).

    Tiger Beetles of the United States and Canada

    44

    Figure 5.1 Representative larval species(third instar) from each of the four genera oftiger beetles found in Canada and the UnitedStates (not to scale). A, Common ClaybankTiger Beetle (C. limbalis); B, Pan-AmericanBig-headed Tiger Beetle (T. carolina); C,California Night-stalking Tiger Beetle (O.californicus); D, Great Plains Giant TigerBeetle (A. cylindriformis).

    Figure 5.2 Fifth abdominal segment of larva showing the hooks (stippled areas) ona representative species of each of the four genera of tiger beetles found in Canadaand the United States. A, Giant Tiger Beetle, genus Amblycheila, B, Night-stalkingTiger Beetle, genus Omus; C, Big-headed Tiger Beetle, genus Tetracha, D, CommonTiger Beetle, genus Cicindela.

  • Big-headed Tiger Beetles (Tetracha): Second pair of simple eyes are notless than one-half the diameter of the rst pair; inner and median hooks onfth abdominal hump are similar in shape, thornlike, and with fewer andmore slender setae; inner hooks much smaller; inner and median hooks arenearly touching at their bases (g. 5.2C); fourth antennal segment only slightlyshorter than third segment.

    Common Tiger Beetles (Cicindela): First and second pair of simple eyesslightly different in size; median hooks on fth abdominal segment are long,curved, and sickle-shaped and directed outward; inner hooks are short, cylin-drical, and usually with a short sharp spine (g. 5.2D).

    Key to the Third Instar Larvae of the Genera of Tiger Beetles Found in the United States and Canada

    1a Hump on the dorsal side of fth abdominal Night-stalking Tiger segment with 3 pairs of hooks, middle pair Beetles (Omus)distinctly longer than other two (Fig. 5.2B)

    1b Hump on the dorsal side of fth abdominal segment with 2 pairs of hooks 2

    2a The two pairs of hooks on the hump of the fth abdominal segment different in shape, Common Tiger Beetlesmedian pair long, and curved; inner pair (Cicindela)short and cylindrical (Fig. 5.2D)

    2b The two pairs of hooks on the hump of the fth abdominal segment similar in shape, 3thornlike, but inner hooks distinctly shorter

    3a Inner and middle hooks close together and Big-headed Tiger Beetlesnearly touching at their bases (g. 5.2C) (Tetracha)

    3b Inner and middle hooks distinctly separated Giant Tiger Beetlesat their bases, not touching (g. 5.2A) (Amblycheila)

    Identication of Tiger Beetle Larvae

    45

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  • We use Freitags Catalogue of the Tiger Beetles of Canada and the United Statesand Wiesners Checklist of the Tiger Beetles of the World as a taxonomic basis forthe status of names. Any deviations from these classication schemes are in-dicated and justied. Group names of genera and higher taxa are arranged inroughly phylogenetic order so that closely related (and often most similar ap-pearing) species are close together. For other explanations of taxonomic de-tails, consult Freitags and Wiesners catalogs. We also use the most widely ac-cepted common names of tiger beetle species in conjunction with scienticnames. Subspecies, however, are indicated only by their scientic moniker.

    Distribution Maps

    Using a compilation of published regional records and collection data fromspecimens in museums and personal collections, we assembled the most com-plete and current distributional status possible for each tiger beetle speciesand recognized subspecies occurring within the political boundaries of theUnited States and Canada. For convenience, we have illustrated these geo-graphic ranges with area maps, and state and province boundary lines helpspecify each range map. All subspecies for each species are included on thesame map and distinguished with different patterns of shading. Areas of sub-species intergradation are indicated by overlapping shading types.

    Each of these distribution maps is an approximate outline dened byrecords at the extreme edges of the species distribution. Please note, however,that no species will occur everywhere within the indicated range. There aremany areas within a distribution where the specic habitat for that speciesdoes not exist and from which it is thus absent. However, only when a speciesis absent from signicantly large intermediate areas do we indicate these ab-sences on the range map. In some instances, however, it is more appropriateto represent the distribution or parts of the distribution with individual sym-bols (triangles or diamonds). Species restricted to narrow coastal distributionsand those that have extremely specialized and disjunct habitat requirements aremore conveniently presented in this manner. Similarly, for isolated colonies andvagrant individuals we use individual symbols with arrows indicating probableroutes of dispersion.

    47

    6Species Accounts

  • Giant Tiger Beetles, Genus Amblycheila

    The seven species of this strictly nocturnal genus are conned to the westernUnited States and northern Mexico. Five species occur north of Mexico, andtwo, A. nyx, from Quatrocienegas Bolson in west-central Coahuila, and A. half-fteri from San Luis Potosi, are endemic to northeastern Mexico. Adults of thisgenus are ightless, with fused elytra, are all dark brown to black, and are thelargest tiger beetles in the Western Hemisphere. Each species occupies a dis-tinctive habitat, and no two species are known to occur together at the samesite. Giant Tiger Beetles are not attracted to lights at night.

    Montane Giant Tiger Beetle, Amblycheila baroni Rivers(Plate 1) [Map 1]

    Description and similar species: Length: 2025 mm; all black to dark brownwith a smooth but dull or matte surface on the elytra; a single (rarely two), in-distinct, raised pleat (carina) runs the length of the elytron just above theouter edge (see g. 4.3A). Shallow pits (punctae) on the elytral surface are in-distinct. Other species of this genus are similar in shape, and color, but theyall are larger, have a shiny surface to the elytra, and/or three or more distinctcarinae on each elytron.

    Subspecies and morphological variants: No distinct subspecies or geograph-ical variations are recognized.

    Distribution and habitats: Restricted to open pinyon-oak-juniper areas ofsouthern and central Arizona at mid-elevations above 900 m with sand to

    gravel substrate and huge granite boulder elds. A possiblerecord from similar habitat in west Texas near Big Bend Na-tional Park means that this species may have a much largerrange than now known. Establishing its range accurately, how-ever, is made difcult by a highly disrupted distribution. It isstrangely absent from what appear to be otherwise ideal habi-tats, such as the Pajarito Mountains of south central Arizonaand the Chiricahua Mountains of southeastern Arizona. Thesimilar Mojave Giant Tiger Beetle occupies similar habitat to

    the west, and the two species may overlap in low desert mountains of west-central Arizona.

    Behavior: Adults are completely nocturnal and ightless. They can most fre-quently be seen running across roads through appropriate habitat and alongthe base of the huge, rounded boulders that are a typical part of their habitat.

    Tiger Beetles of the United States and Canada

    48

    Map 1 MontaneGiant Tiger Beetle,Amblycheila baroni.

  • Seasonality: Adult activity is limited to the warm, wet monsoon season fromJuly to September.

    Larval biology: The huge larvae occur in the same habitat as adults and havebeen found under at rocks and around the bases of large rocks and boulders.

    Mojave Giant Tiger Beetle, Amblycheila schwarzi W. Horn(Plate 1) [Map 2]

    Description and similar species: Length 2127 mm; all black to dark brownwith a shiny surface on the elytra, three distinct, raised pleats (carinae) runthe length of the elytron, two along the near-vertical side and the inner onedelineates the at horizontal center of the elytron from the sloping side (seeg. 4.3B). Several rows of distinct, shallow pits run along the sloping elytraledge, and two irregular rows run along the inside of each central pleat. Thecentral at area of the elytra lacks distinct pits. Other species of this genus aresimilar in shape and color, but they have only one pleat (Montane Giant TigerBeetle), or if three pleats, different geographic distributions (Plateau GiantTiger Beetle in the southern intermontane Rocky Mountain area and SouthTexas Giant Tiger Beetle), or many rows of pits cover the entire center of theelytra (Great Plains Giant Tiger Beetle).

    Subspecies and morphological variants: No distinct subspecies or geograph-ical variations are known for the Mojave Giant Tiger Beetle; however, speci-mens from southern Utah average 23 mm shorter than those from other lo-cations within its range.

    Distribution and habitats: Restricted to open live oak andjuniper areas with large boulder elds and sandy crevicesbetween 1000 and 1500 m in the Mojave Desert. Al-though it overlaps geographically with the Plateau GiantTiger Beetle, the Plateau Giant Tiger Beetle is restrictedto lower altitude grassland areas. The Montane GiantTiger Beetle and Mojave Giant Tiger Beetle may occur to-gether in low mountains of central western Arizona.

    Behavior: Adults are completely nocturnal and ight-less. They can most frequently be seen running in drywashes and along the base of the huge, rounded boul-

    ders that are a typical part of their habitat, especially after rains.

    Seasonality: Adult activity is primarily in the spring, April to June, and againin August.

    Larval biology: Larva unknown.

    Species Accounts

    49

    Map 2 Mojave Giant TigerBeetle, Amblycheila schwarzi.

  • Great Plains Giant Tiger Beetle, Amblycheila cylindriformis Say(Plate 1) [Map 3]

    Description and similar species: Length 2935 mm; all black to dark brownwith a shiny surface on the elytra that has many closely spaced rows of dis-tinct pits over the entire surface. Three distinct, raised pleats (carinae) run thelength of each elytron, two along the near-vertical sides and the inner one onthe upper part of the elytron. Other species of this genus are similar in shapeand color, but no other Giant Tiger Beetle species has the entire surface of theelytra covered with rows of pits.

    Subspecies and morphological variants: No distinct subspecies or geograph-ical variations are known.

    Distribution and habitats: Limited to grassland andprairie areas, pastures, and well-drained bare orsparsely vegetated soil. This species is found be-tween 540 and 1460 m in the Great Plains. It hasalso been observed on clay banks near creeks,rivers, and ravines as well at the tops of low cliffs.

    Behavior: Adults are completely nocturnal andightless. They can most frequently be seen run-ning across roads and through open patches of bareearth in grasslands. Adults pass the daylight hoursunderground, often in rodent burrows.

    Seasonality: Adult activity is from April to September in the southern part ofits range and June to August in the northern part of its range.

    Larval biology: The huge larvae occur in the same habitat as adults, and theyhave been found in the fresh dirt at the mouths of prairie dog, badger, and go-pher tunnels as well as on near-vertical faces of clay bluffs. They tend to occurin clusters of 210 individuals within a 25 cm radius, and they forage mainlyafter sunset but also on cloudy days.

    South Texas Giant Tiger Beetle, Amblycheila hov