Revision of the genus Ischyrus Lacordaire (1842) (Erotylidae: triplacinae) of North and Central America


Material Information

Revision of the genus Ischyrus Lacordaire (1842) (Erotylidae: triplacinae) of North and Central America
Physical Description:
x, 362 leaves : ill., photos ; 29 cm.
Skelley, Paul Edward, 1964-
Publication Date:


Subjects / Keywords:
Beetles -- Identification   ( lcsh )
Beetles -- Geographical distribution   ( lcsh )
Beetles -- Classification   ( lcsh )
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )


Thesis (Ph. D.)--University of Florida, 1994.
Includes bibliographical references (leaves 348-361).
Statement of Responsibility:
by Paul Edward Skelley.
General Note:
General Note:

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 001986588
notis - AKG3558
oclc - 32021372
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Full Text







Copyright 1994


Paul Edward Skelley


I thank my committee, R. E. Woodruff and M. C. Thomas,

Florida State Collection of Arthropods, and D. H. Habeck and

J. W. Kimbrough, University of Florida, for their guidance,

encouragement, assistance, and editorial comments for this

and many other studies. Without them I would never have

attained my goals. I thank M. A. Goodrich, Eastern Illinois

University, for assistance during this study and for his

continued support with other studies on the Erotylidae.

For loans of specimens, including types, I thank the

following people and their associated institutions: F. G.

Andrews, California State Collection of Arthropods; R. S.

Anderson, Canadian Museum of Nature; J. S. Ashe, R. W.

Brooks, and R. A. B. Leschen, Snow Entomological Museum,

University of Kansas; D. Azuma, Academy of Natural Sciences,

Philadelphia; A. O. Bachmann, Museo Argentino de Ciencias

Naturales; N. Berti, Museum National d'Histoire Naturelle,

Paris; R. L. Blinn, University of Missouri; M. Brancucci,

Naturhistorisches Museum Basel; R. L. Brown, Mississippi

State University; C. Carlton, University of Arkansas; E. D.

Cashatt, Illinois State Museum; R. D. Cave, Escuela Agricola

Panamericana, Tegucigalpa, Honduras; D. S. Chandler,

University of New Hampshire; F. A. Cholick, South Dakota

State University; S. M. Clark, West Virginia Department of


Agriculture; W. E. Clark, Auburn University; C. Covell,

University of Louisville, Kentucky; D. P. Cowan, Western

Michigan University; R. L. Davidson, Carnegie Museum of

Natural History; K. Desender, Institute Royale des Sciences

Naturalles de Belgique; M. A. Deyrup, Archbold Biological

Station; M. E. Douglas, Arizona State University; O. V.

Ferreira, FundaQ&o Oswaldo Cruz; R. W. Flowers, Florida A. &

M. University; W. A. Foster, University of Cambridge, United

Kingdom; P. H. Freytag, University of Kentucky; M. H. M.

Galileo, Museu de Cidncias Naturais, Porto Alegre, Brazil;

M. A. Goodrich, Eastern Illinois University; I. Goreyeb and

T. P. Chaves, Museu Paraense Emilio Goeldi; L. H. Herman,

American Museum of Natural History; M. W. Heyn, Clemson

University; F. Hieke, Museum fOr Naturkunde der Humboldt-

Universitdt zu Berlin; G. N. House, United States National

Museum; N. Johnson and P. W. Kovarik, Ohio State University;

D. H. Kavanaugh and R. Brett, California Academy of

Sciences; M. D. Kerley, Natural History Museum, London; B.

C. Kondratieff, Colorado State University; M. Kosztarab,

Virginia Polytechnic Institute and State University; S.

Krauth, University of Wisconsin; W. E. LaBerge and K. C.

McGriffen, Illinois Natural History Survey; P. K. Lago,

University of Mississippi; J. F. Lawrence, CSIRO, Canberra,

Australia; R. Lawson, Chadron State College; R. E. Lewis,

Iowa State University; J. K. Liebherr, K. E. M. Galley, and

J. V. McHugh, Cornell University; J. McNamara, Canadian

National Collection of Insects; J. E. McPherson, Southern

Illinois University; O. Merkl, Hungarian Natural History

Museum; C. R. Nelson, Brigham Young University; A. F.

Newton, Jr., and P. Parillo, Field Museum of Natural

History; D. NThez, Escuela Nacional de Ciencias Forestales,

Honduras; M. F. O'Brien, University of Michigan Museum of

Zoology; C. A. Olson, University of Arizona; G. Onore,

Pontificia Universidad Cat6lica de Ecuador; C. S. Parron,

North Carolina State University; S. Pratt, Museum of

Comparative Zoology, Harvard University; A. Provonsha,

Purdue University; B. C. Ratcliffe, University of Nebraska

State Museum; E. G. Riley, Texas A. & M. University; R. A.

Ronderos, Universidad Nacional de La Plata, Argentina; S.

Santiago, Universidad Nacional Aut6noma de M6xico; G.

Scherer, Zoologische Staatssammlung, Minchen; Y. Sedman,

Western Illinois University; D. Shpeley and D. A. Pollock,

Strickland Museum, University of Alberta; C. L. Smith,

University of Georgia, Athens; R. R. Snelling, Los Angeles

County Museum; C. A. Springer, Hastings College, Nebraska;

F. W. Stehr, Jr., Michigan State University; A. L. TerAn,

Fundaci6n Miguel Lillo, Tucuman, Argentina; R. E. Woodruff

and M. C. Thomas, Florida State Collection of Arthropods; R.

S. Zack, Washington State University; L. Zerche, Deutsches

Entomologisches Institut, Eberswalde-Finow.

I thank the following private collectors for allowing

me to study their collections: A. Allen, R. J. Barney, J. L.

Carr, J. M. Cicero, E. J. Ford, S. M. Fullerton, D. H.

Habeck, M. A. Ivie, D. H. Kavanaugh, P. K. Lago, R. A. B.

Leschen, R. W. Lundgren, S. McCleve, J. V. McHugh, R. F.

Morris, G. H. Nelson, T. K. Philips, R. Prange, W. Suter, R.

H. Turnbow, Jr., J. E. Wappes, and J. Watts.

For assistance in locating types, I thank W. A. Foster,

Cambridge University, United Kingdom; F. Hieke, Museum fur

Naturkund der Humboldt-Universitdt zu Berlin;

D. S. Horning, University of Sydney; M. D. Kerley, Natural

History Museum, London; G. C. McGavin, Oxford University.

For assistance with the scanning electron microscope

and specimen preparation techniques, I thank H. Cromroy and

W. Carpenter, University of Florida. For darkroom

assistance and other photographic reproductions, I thank J.

Lotz, Division of Plant Industry, Florida Department of

Agriculture and Consumer Services.

I thank E. Mayr, J. McCarthy, and E. Langosy, Harvard

University, for the support of an Ernst Mayr Grant, which

allowed me to study specimens in both the Crotch Erotylidae

Collection, Cambridge University, and the Natural History

Museum, London. This study would not have been completed

without their assistance.

I thank M. C. Thomas, Florida State Collection of

Arthropods, for assistance with computer graphic programs

used in the illustrations. I thank all of the personnel

(too numerous to mention) at the Florida Department of

Agriculture and Consumer Services, Florida State Collection

of Arthropods, for their support and tolerance during my

eight years of study.

If I have unknowingly omitted anyone, I thank them here

for their assistance.

Last, yet foremost, I thank my parents, Paul F. and

Antoinette, and my wife, Lucy, for their encouragement and

love over these many years.



ACKNOWLEDGMENTS .................................. ........ iii


................... ............................ x

INTRODUCTION ............................................... 1

General Introduction ................................ 1
History ............................................. 2
Nomenclatural Status ............................... 6
Format of Species Accounts ......................... 8
Characters and Terminology ........................... 11
Basics .......................................... 11

Eye Facets ...
Punctation ...
Surface ......
Body Shape ...
Color Pattern
Head .........
Elytra ......
Ventral Lines
Prosternum ...

First Visible Abdominal Sternite ..............
Male Genitalia ................................
Female Genitalia ..............................
Materials and Methods ..............................
Specimens .....................................
Locating Types ................................
Collecting ....................................
Equipment .....................................
Techniques ....................................
Color Pattern Problems ........................
Rules of Thumb ................................
Results .......................................

ISCHYRUS LACORDAIRE .....................................

ARTIFICIAL KEY TO SPECIES ...............................

SPECIES ACCOUNTS ........................................

Ischyrus aleator Boyle .............................
Ischyrus angularis Lacordaire ......................
Ischyrus auriculatus Lacordaire ....................



... .. .. ... .. .. ... .. .. ..

Ischyrus bogotae Crotch ...........................
Ischyrus boucardi Crotch ..........................
Ischyrus chacojae Gorham ..........................
Ischyrus collatinus Crotch ........................
Ischyrus distinguendus Lacordaire .................
Ischyrus dunedinensis Blatchley ...................
Ischyrus elegantulus Lacordaire ...................
Ischyrus ephippiatus Gorham .......................
Ischyrus episcaphulinus Gorham ....................
Ischyrus frontalis Lacordaire .....................
Ischyrus fulmineus Delkeskamp .....................
Ischyrus incertus Lacordaire ......................
Ischyrus insolens Crotch ..........................
Ischyrus pictus Gorham ............................
Ischyrus proximus Lacordaire ......................
Ischyrus quadripunctatus (Olivier) ................
Ischyrus quadripunctatus quadripunctatus (Olivier)
Ischyrus quadripunctatus chiasticus Boyle, New Stat

Ischyrus scriptus (Olivier) .......................
Ischyrus scutellaris Gorham .......................
Ischyrus septemsignatus Gorham ....................
Ischyrus tetrasticus Gorham .......................
Ischyrus tripunctatus Crotch ......................
Ischyrus undulatus Gorham .........................
Ischyrus vespertilio Lacordaire ...................
Ischyrus n. sp. 1 .................................
Ischyrus n. sp. 2 .................................
Ischyrus n. sp. 3 .................................
Ischyrus n. sp. 4 .................................
Ischyrus n. sp. 5 .................................
Ischyrus n. sp. 6 .................................
Ischyrus n. sp. 7 .................................
Ischyrus n. sp. 8 .................................
Ischyrus n. sp. 9 .................................
Ischyrus n. sp. 10 ................................
Ischyrus n. sp. 11 ................................
Ischyrus n. sp. 12 ................................
Ischyrus n. sp. 13 ................................
Ischyrus n. sp. 14 ................................
Ischyrus n. sp. 15 ................................
Ischyrus n. sp. 16 ................................

. 99

APPENDIX A: ISCHYRUS SPECIES NAMES .................... 308


APPENDIX C: SPECIMEN LABEL DATA ........................ 320

LITERATURE CITED ....................................... 348

BIOGRAPHICAL SKETCH ...................................... 362

Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy



Paul Edward Skelley

April 1994

Chairman: Robert E. Woodruff
Major Department: Entomology and Nematology

This revision treats all known species of the genus

Ischyrus Lacordaire occurring from Panama north. A key to

the species, descriptions and illustrations of terms used,

habitus and genitalic illustrations for all species,

distribution maps, detailed species descriptions, complete

synonymies, label data from specimens studied, and

comparisons with similar species are presented to aid in the

identification of specimens. A list of all names used in

combination with Ischyrus and their current status is

presented to prevent future homonyms. A total of 26, valid

previously described species is addressed, nine new

synonymies made, and 16 new species described.

General Introduction

The family Erotylidae is composed of fungus-feeding

beetles that vary in body size and color; many are

elaborately patterned. Recently published catalogs detail

the Old World species (Delkeskamp 1981; ChQj6 & ChQj6 1988,

1989, 1990). In contrast, Crotch's (1876) world revision

of the Erotylidae was the last study to cover the entire

New World fauna, but it provided no keys or illustrations

and few descriptions. Since Crotch's time, the New World

erotylid fauna has been studied intermittently, with

scattered regional studies, catalogs, and species

descriptions. Most New World erotylid genera have no

modern revision.

The purpose of this study is to begin bringing the

nomenclature of the New World Erotylidae into the 20th

century and to publish the results in a manner that will

enable entomological students to identify their specimens.

"Progress in Natural History necessarily starts from a

basis of species, and until these are accurately described

so that others can arrive at a knowledge of them no great

advance is possible" (Horn 1887:7).

Nomenclatural changes and lectotype designations made

in this dissertation are not to be considered valid until

they are published. Holotypes are not selected and names

are not proposed for the new species to avoid potential

nomenclatural problems.


The first described member of the genus Ischyrus

Lacordaire is Erotylus quadripunctatus Olivier (1792). The

first use of the name Ischyrus was by Chevrolat in fascicle

5 of the second edition of Dejean's catalog (1836).

Because most of the second edition was burned in a fire,

the third edition of the Dejean catalog (1837) was

immediately printed. (See Madge, 1988, for dates of

publication and history of the Dejean catalogs.)

Dejean's (1836, 1837) catalogs were among the first

works to split the genus Erotylus Fabricius (1775) into

more manageable, related taxa. Species and generic

concepts were in their infancy during the early 1800s. For

the Erotylidae, Dejean's genera appear to be groups of

species with similar body size and color. This is evident

in the proposed genus Ischyrus Chevrolat containing large

dull-black species, Mycotretus Chevrolat containing smaller

species with yellow and black color patterns, and Lybas

Chevrolat containing species that were oval and solid red.

Dejean's catalogs were simply checklists of his collection

in which many generic and specific names were proposed.

Because the Dejean names lacked descriptions, they were

often ignored by early taxonomists.

The next use of the name Ischyrus was by Falderman

(1837) in describing Ischyrus lepidus, presently a member

of Triplax Herbst (1793) (fide ChOj6 & ChOj6 1990). The

name Ischyrus was then used as a subgroup of Erotylus

Fabricius (1775) by Gu6rin-M6neville (1841) in describing

E. (Ischyrus) nebulosus, presently a member of

Brachysphaenus Lacordaire (1842) (fide Crotch 1876). These

uses of "Ischyrus" illustrate early workers' attempts at

placing new species into taxa based on superficial


Lacordaire (1842) was the first person to provide a

description of the genus Ischyrus, for which he gave credit

to Chevrolat in Dejean (1836) as the author of the name.

He moved many previously described species into Ischyrus

and described 17 new species. Unfortunately, Lacordaire

did not designate a type species for Ischyrus.

Lacordaire split the genus into two divisions. The

first division contained species with larger body size and

strongly keeled prosternum, mostly species listed in the

Dejean catalogs as Ischyrus Chevrolat. The second division

contained species with smaller body size and a weakly

keeled prosternum, mostly species listed under Mycotretus

Chevrolat in the Dejean catalogs, including Erotylus

quadripunctatus Olivier. Lacordaire based his generic

concepts on reasonably sound morphological features that

are still in use. He also maintained many previously

published species names that had not been described [nomina

nuda]. With his descriptions, Lacordaire became the author

of these names.

Subsequent authors, Guerin-Meneville (1844) and

Erichson (1847), used Lacordaire's generic names and

described seven additional species of Ischyrus.

Crotch (1873b) separated Lacordaire's divisions into

distinct genera. The first division, containing species of

larger size, he named Megischyrus. The second division,

containing species of smaller size, he maintained as

Ischyrus, crediting Lacordaire as the describer and noting

the original use of the name by Chevrolat in Dejean (1836).

At that time, it was common to give credit for a name to

the first describer of the taxon and not to the author of

that name. Following this trend, Crotch cited it as

Ischyrus Lacordaire.

In 1873 Crotch received a grant to visit tropical

Australia and adjacent islands to collect natural history

specimens. Before his departure from Cambridge, U.K., he

placed his collection and manuscript in the care of E. W.

Janson. Unfortunately, Crotch became ill and died in 1874

while in the U.S.A. Edward W. Janson put Crotch's

manuscript into final form and published it. Numerous

notes within the revision are undoubtedly those of Janson.

Without Crotch's input, many of the species problems

alluded to within the text were left unresolved. This

"revision" is simply an annotated catalog of the species

previously described, with brief descriptions of the new

species. Yet, it has been the basis for all subsequent

studies of the family. The name Ischyrus Lacordaire, as

cited and used in Crotch's revision, was accepted and used

by all subsequent workers, with the exception of Alvarenga

(1965, discussed below). Crotch (1876) listed 44 species

of Ischyrus, 13 of which were new species.

Ischyrus Lacordaire (sensu Crotch) has been referenced

in a multitude of papers and texts. Many of these are

simply species descriptions, regional studies, catalogs,

general entomological texts, or biological accounts. These

are too numerous to list here, but they can be found in the

species accounts of this revision.

Some of the more important references are worth

noting. Gemminger and Harold's (1876) Catalogus

Coleopterorum was published shortly after Crotch's revision

and contains the names as used by Crotch. Gorham (1887-

1899), in the Biologia Centrali-Americana, gave accounts

for 22 species of Ischyrus that included 10 new species.

Kuhnt (1909, 1911) provided two catalogs, the first of

which contained a simple grouping of the species by various

color pattern characters.

The most recent catalog of the genus Ischyrus

Lacordaire is Blackwelder's (1945) Checklist of the

Coleopterous Insects of Mexico, Central America, the West

Indies, and South America, which lists 56 names. Boyle

(1954, 1956) revised the family Erotylidae for America,

north of Mexico, thoroughly describing the genus Ischyrus

and one new species.

The most recent paper of importance to the genus

Ischyrus Lacordaire is Alvarenga (1965). Following current

nomenclatural rules, Alvarenga realized that Crotch (1873b)

had incorrectly applied the name Ischyrus and selected an

invalid type species. Alvarenga made some major changes in

the standing of the names Ischyrus and Megischyrus, which

are discussed in the following section.

Before the present study, there were 65 valid species

placed in the genus Ischyrus Lacordaire. This study

addresses 26 of these, synonymizes 9, and describes 16 new

species. This brings the total to 72 species. (See

Appendix A for a list of all specific names used in

association with Ischyrus and their current status.)

Nomenclatural Status

The early nomenclature of this genus is typical for

many taxa, with names being proposed and ignored. The name

Ischyrus Chevrolat in Dejean (1836) is a nomen nudum (name

without description) and was not valid in the opinion of

some early workers. Thus, the first use of the name to be

accompanied by a description was the valid name. Crotch

(1873b) undoubtedly had this in mind when he raised

Lacordaire's divisions to full generic status. Crotch

proposed the name Megischyrus for Lacordaire's first

division, designating Erotylus undatus Olivier as the type

species. Crotch retained the name Ischyrus for the second

division, crediting Lacordaire as the first describer of

the genus, and designated Erotylus quadripunctatus Olivier

as the type species. This was accepted and used by all

subsequent workers until Alvarenga (1965) found some errors

in the type designations and credits for these genera.

According to the current International Code of

Zoological Nomenclature (1985) the first valid use of a

name is to be followed--the Law of Priority. Before 1931,

the first use of a generic name is valid if it is followed

by a description or has a valid species name listed under

it, an indication. Also, in designating a type species for

a genus subsequent to its first use, the reviser

designating the type must choose a species from those

originally included within the genus (as indicated by

Barber & Bidwell 1940). This makes the Dejean catalogs

(1836, 1837) the first valid uses of the generic name

Ischyrus, and the type species should have been chosen from

the species listed within it.

According to these rules, Crotch (1873b) had

incorrectly chosen the type species of Ischyrus, because

Erotylus quadripunctatus was not listed in Dejean (1836) as

Ischyrus. Erotylus undatus Olivier was listed under the

name Ischyrus Chevrolat in Dejean (1836). Crotch chose

Erotylus undatus as the type species of his genus

Megischyrus. This makes Megischyrus Crotch an objective

synonym of Ischyrus Chevrolat, leaving Ischyrus Lacordaire

(sensu Crotch) without a valid name.

Discovering these problems, Alvarenga (1965) corrected

them by synonymizing Megischyrus Crotch under Ischyrus

Chevrolat, designating Erotylus undatus Olivier as the type

species. For Ischyrus Lacordaire (sensu Crotch) he

proposed the name Micrischyrus, designating Erotylus

quadripunctatus Olivier as the type species. In essence,

he discarded one name, moved another, and proposed a third.

In my opinion, Alvarenga's actions were not fully

justifiable because they create unnecessary confusion. The

main purpose of the International Code of Zoological

Nomenclature is to stabilize nomenclature, as stated in its

preamble. The code has provisions (Article 79) to conserve

long-standing, widely accepted names like Megischyrus

Crotch and Ischyrus Lacordaire (sensu Crotch). Therefore,

a proposal has been submitted to the International

Commission of Zoological Nomenclature (Skelley & Goodrich,

in press) to conserve these names by suppressing all uses

and indications of the name Ischyrus prior to Ischyrus

Lacordaire (1842). Pending the ruling of the Commission, I

am using the name Ischyrus Lacordaire (sensu Crotch), in

preference to Micrischyrus Alvarenga, as the name for the

genus studied in this revision.

Format of Species Accounts

Title. This heading is the valid name for the species

to be discussed.

Synonymy. This section lists all combinations of the

specific name and any synonyms of the valid name. These

are organized in the following manner: Genus species

describer date:page [comments], author of the synonymy or

combination date:page. Example: Engis variegata Dejean

1821:45 [nomen nudum], Gemminger & Harold 1876:3691.

Diagnosis. This section lists the set of characters

separating the species under consideration from all known

species in the genus.

Description. This section is a detailed description

of the species being discussed. It is organized in the

following manner: body measurements, overall appearance,

color pattern, head and antenna, visible mouthparts,

pronotum, scutellum, elytra, prosternum, mesosternum,

metasternum, first visible abdominal sternite, male

genitalia, female genitalia, stridulatory files, sexual

dimorphisms. Legs are not described because no characters

of use at the species level were found.

Variation. This section is a discussion of the color

pattern or morphological features that vary from specimen

to specimen in the species.

Type. Here I list the type specimens for all species

names appearing in the synonymy, their label data, type

locality (if not on their labels), current location, sex,

and if they were studied.

Label data for type specimens are given in the

following manner: "/ label data/ [my comments] label data/"

[XXXX]. The quotation marks, ", indicate the beginning

and ending of the data. The slash marks, /, indicate the

beginning and ending of an individual label. My comments

are placed in brackets, [ ], and usually indicate paper

color or label shape. When no comment is made, the paper

is white. After the label data are presented, a coden is

given in brackets, [XXXX], for the institution (see

Appendix B) where the specimen it is currently located.

Many species needed lectotypes designated. A red

"lectotype" label was placed on these specimens and dated

when they were designated as the "type."

Type specimens of previously described species were

dissected only if it was absolutely necessary to solve a

species problem. Since this was such a rare occurrence,

determining the sex of the types was accomplished using

external characters. In some cases, where sexual

dimorphism is distinct, the determination was easy. In

most cases, when the sex was unclear, it is listed as "not


Specimens examined. Here I list the label data for

all specimens studied, if there were fewer than ten

records. Species with more than ten collection records

have their data presented in tabular form in Appendix C to

help keep the text uncluttered and to present it in a more

usable format.

Distribution. A brief account of the known geographic

distribution of the species is presented. A map is

provided for each species to illustrate the distribution.

Etymology. An attempt is made to present what the

species epithet means and possibly why the original author

chose it. This is included more for historical purposes

and may help the reader remember the name. Brown's (1985)

Composition of Scientific Words was an indispensable

reference in this research.

Taxonomic notes. This section includes nomenclatural

aspects that need clarification. I present some unsolved

problems of taxonomic importance indicating that this

revision is just a beginning.

Biologv. This section is included only for the few

species where some biological or life history data are


Remarks. This section contains statements on similar

species and how to separate them from other species being


References. This section lists the references where

the species name occurs. Each species name appearing in

the synonymy is listed separately to aid in future

literature searches for specific names other than the valid


Characters and Terminology


Most general terms follow the meaning presented in The

Torre-Bueno Glossary of Entomology (Nichols & Schuh 1989).

Terms for the genitalia follow Sharp and Muir (1912),

Tanner (1927), and Boyle (1956). Some characters and terms

need further explanation, as follows.

Eye Facets

Eye facet size, coarse vs. fine, is used to separate

many genera in the Triplacinae. This character is based on

the relative size and distinctiveness of the eye facets in

relation to the head. Coarse facets (Fig. la) are larger

and more prominent, often bulging from the surface. Fine

facets (Fig. Ib) are smaller and less prominent, with a

smoother eye surface. There are many species that are

intermediate in facet development, making this character

difficult to interpret.


The puncture size is compared with the eye facet:

facet diameter to puncture diameter. Most Ischyrus species

have coarse punctation where the punctures are as large or

larger in diameter than a facet.

Punctures can be normal, impressed, or foveate. A

normal puncture appears like a simple pinprick. Impressed

punctures are deep punctures, usually with a rounded edge

and bottom. Foveate punctures are large, shallow, flat-

bottomed punctures, usually with a distinct edge.


The body is generally covered with a hexagonal micro-

sculpturing. Variations in the strength of this

microreticulation change the surface from shiny to dull and

are visible to the naked eye.

Figure 1. Dorsal view of heads showing eyes: a.) Ischyrus
q. quadripunctatus (Olivier) with coarsely faceted
eyes, line = 0.5 mm; b.) Tritoma atriventris LeConte
with finely faceted eyes, line = 0.38 mm. The arrow
points to the ocular stria.

Body Shape

Most of the species are flattened to slightly convex

dorsally; vespertilio Lacordaire and duponti Lacordiare are

convex dorsally (Fig. 2a, 2b). Most parallel-sided bodies

(Fig. 2c) are flattened dorsally. Most elongate bodies

have the sides parabolically rounded (Fig. 2d) and are

slightly convex above. Oval bodies (Fig. 2e) are rounded

on the sides and can be flattened or convex dorsally.

Ovoid bodies are egg-shaped (Fig. 2f) and wider anteriorly

and can be flattened or convex dorsally.

Color Pattern

Color patterns are the most useful characters in the

recognition of species. Understanding the terms for

various aspects of the color pattern is essential in using

the key (Fig. 3).

A band is a wide transverse marking, wider than long.

A stripe is a longitudinal marking, longer than wide. A

spot is a small marking, usually circular or elongate. I

use the term "fascia" to mean a band that may be broken by

additional markings. A free spot is not connected to any

margin. A tooth-like spot is a triangular spot connected

to a margin.

The color patterns of most species are variations of a

basic pattern. I have named the components of the pattern

in reference to its position on the body (Fig. 4): anterior

pronotal, free pronotal, basal pronotal, pronotal hind

angle, humeral, subhumeral, scutellar, elytral suture,

c d

e f

Figure 2. Ischyrus body shapes: a.) flattened;
b.) convex; c.) parallel-sided; d.)
elongate; e.) oval; f.) ovoid.

st FSp

B {B

Fj F

Figure 3. Diagrammatic representation
of color pattern terms: B = band,
F = fascia, FSp = free spot, Sp =
spot, St = stripe, TSp = tooth-
like spot.

Figure 4. Diagrammatic representation of a
generalized color pattern indicating
spot names: Ae = apical elytral, Ap =
anterior pronotal, Bp = basal pronotal,
Ce = central elytral, Es = elytral
suture, Fp = free pronotal, Hu =
humeral, Le = lateral elytral, Pha =
pronotal hind angle, Shu = subhumeral,
Sc = scutellar, Sc + Hu = basal elytral
band, Ce + Le = central elytral band.

central elytral, lateral elytral, and apical elytral. When

the scutellar and humeral spots are connected, they make up

the basal elytral band. When the central and lateral

elytral spots are connected, they make up the central

elytral band.


The dorsal surface of the head has relatively few

useful characters. On each side of the vertex following

the margin of the eye is a line or shallow groove, the

ocular stria (Fig. 1). Its length appears to be useful at

generic levels and is commented upon for future reference.

Since this line is shorter than the eye length in the vast

majority of Ischyrus, its length is given as a decimal that

indicates how far forward the line reaches on the eye. For

example, it could reach "0.75 distance to the anterior

angle of the eye," which means the line stops 3/4 of the

distance from the base to the anterior angle of the eye.

In Figure la, the ocular stria stops at the anterior angle.

The head size vs. eye size is given as a proportion:

head width between eyes = "N" eye widths (Fig. 5). The

smaller the eyes or the wider the head, the larger the

number "N".

The base of the head often has structures which have

been called stridulatory files (Alexander et al. 1963;

Arrow 1924, 1925, 1942; Delkeskamp 1959). These structures

appear as iridescent spots under a dissecting microscope.

Study with the scanning electron microscope shows them to

Figure 5. Diagrammatic dorsal view of
a head showing the measurements
used for determining the ratio of
head to eye width; dorsal head
width between eyes = y/x times
eye width.

be patches of parallel ridges. Even though these have been

called stridulatory, I have found no statement about the

sound produced. They appear only on males in some species

and on both sexes in others. The exact function of these

structures is unknown.

Representative species' antennae are illustrated on a

single plate for ease in comparison (Fig. 6). If a species

antenna is not illustrated, a reference is given to the

antenna that is most similar: "(similar to Fig. X)", where

"X" is the figure number.

The shape and proportions of the maxillary and labial

palp terminal segments are important for species

distinctions. These are illustrated on a single plate

(Fig. 7) for ease in comparing shapes and proportions.

This plate illustrates the palpi of representative species

to show the basic forms. The descriptions of species with

similar palpi have the statement "(similar to Fig. X),"

which refers to the figure "X" that is most similar to that

seen in the species being discussed.

The "triangular mentum" is a characteristic of

Ischyrus. The "triangle" is a sunken area of the mentum

surrounded by a ridge (Fig. 8). The triangular sunken area

is the mental plate. The ridge surrounding the plate is

the mental ridge; it is often extended forward at the

middle as a sharp divider between the labial palps. This

projection is called the medial ridge extension. As with

palp terminal segments, representative menta are












Figure 6. Antennae, line = 1.0 mm: a.) Ischyrus
distinguendus Lacordaire; b.) I. n. sp. 2; c.) I.
insolens Crotch; d.) I. bogotae Crotch; e.) I.
angularis Lacordaire; f.) I. q. quadripunctatus
(Olivier); g.) I. n. sp. 3; h.) I. n. sp. 4; i.) I.
n. sp. 6; j.) I. n. sp. 5; k.) I. n. sp. 1; 1.) I.
n. sp. 9; m.) I. n. sp. 14; n.) Megischyrus zonalis
(Lacordaire); o.) Megischyrus sp.





f g

o k


q >7

Figure 7. Terminal segments of labial palp (left) and
maxillary palp (right), line = 0.33 mm: a.)
Ischyrus distinguendus Lacordaire; b.) I. n. sp.
2; c.) I. insolens Crotch; d.) I. bogotae Crotch;
e.) I. septemsignatus Gorham; f.) I. q.
quadripunctatus (Olivier); g.) I. n. sp. 3; h.)
I. undulatus Gorham; i.) I. n. sp. 4; j.) I. n.
sp. 6; k.) I. n. sp. 7; 1.) I. n. sp. 5; m.) I.
aleator Boyle; n.) I. n. sp. 1; o.) I. n. sp. 9;
p.) I. ephippiatus Gorham; q.) I. tripunctatus


1 m


a b

d e


Figure 8. Menta, line = 0.33 mm: a.) Ischyrus
distinguendus Lacordaire; b.) I. n. sp. 2; c.)
I. insolens Crotch; d.) I. bogotae Crotch; e.)
I. n. sp. 3; f.) I. n. sp. 4; g.) I. n. sp. 6;
h.) I. n. sp. 5; i.) I. aleator Boyle; j.) I.
ephippiatus Gorham; Lp = labial palp, P =
mental plate, R = mental ridge, Re = mental
ridge medial extension.

illustrated on a single plate (Fig. 8) and are often

referred to in the text as "(similar to Fig. X)."


Except for color patterns mentioned above, the elytra

have few useful characters. One is the number of elytral

striae and the strength of the strial punctures. Most

species have seven complete striae; stria I next to the

elytral suture, striae V and VI originating at the humerus.

Stria VIII on most species is reduced to a short row of

punctures visible at the basal quarter under the humerus

and/or the apical quarter near the lateral edge of each

elytron. Two species (I. n. sp. 6 & I. n. sp. 7) have

stria VIII complete, one species (I. n. sp. 1) has parts of

stria IX visible.

The size of the strial interval punctures is variable

from species to species. In the majority of species the

punctures are small and obscured in the microsculpturing.

In a few other species they are large and distinct,

occasionally obscuring the strial punctures.

Ventral Lines

A "line" refers to a ridge or fine groove on a

sclerite that is not a suture, but probably has some

supportive function. These lines surround the coxae and

often extend onto the sclerite (Fig. 9). The term "coxal

line" is used in reference to the line on the median side

of the coxa. The lines anterior or posterior to the coxae

are referred to by the structure they are on or near; e.g.,

Figure 9. Ventral view of a.) Ischyrus proximus Lacordaire
and b.) I. n. sp. 1, line = 1.0 mm: Al = abdominal
coxal line, Ee = epipleural fold of elytron, Lap =
prosternal line anterior to procoxa, Lc = coxal line
continuous around coxa, Lnc = coxal line not
continuous around coxa, Lpm = metasternal line
posterior to mesocoxa, Mp = mental plate, Msl =
mesocoxal line, Mtl = metacoxal line, Pe = pronotal
epipleuron, P1 = procoxal line, Pps = prosternal-
pronotal epipleuron suture, Ps = prosternum, Psp =
prosternal plate.

the prosternal line in front of the procoxa or the

metasternal line behind the mesocoxa.

In the majority of Ischyrus species the coxal lines

are not connected to other lines and extend onto the

sclerite (Fig. 9a). If the coxal line is connected to the

anterior or posterior line, it is "continuous around the

coxae," because there is no break in the line surrounding

the coxae (Fig. 9), and the line does not extend onto the



The prosternum is a T-shaped sclerite with the base

between the procoxae and the cap anterior to the procoxae.

The anteromedial section of the prosternum is often keel-

like and elevated above the sides to the level between the

procoxae (Fig. 10), straight in profile. This elevation

makes the anterior margin project at the middle, appearing

as a "pitcher-like lip" (according to Boyle 1956). When

the prosternum is keeled and has this "pitcher-like lip," I

refer to it as being "pinched," because it appears

laterally pinched. The strength of this pinch, also the

amount it projects, is variable throughout Ischyrus and can

be absent (Fig. 10a, 10b), weak (Fig. 10c, 10d), or strong

(Fig. 10e, 10f).

In a few species (for example, I. n. sp. 5, I. n. sp.

6, and I. n. sp. 7) the prosternal keel appears anteriorly

swollen just behind the margin (Fig. 10g, 10h). I call

this "swollen above the pinch."


c, riii~


Figure 10. Prosternal development: a.) ventral and b.)
lateral view of Ischyrus aleator Boyle [Mexico,
Sonora] prothorax lacking anterior pinch, line = 0.60
mm; c.) ventral and d.) lateral view of Ischyrus q.
quadripunctatus (Olivier) [USA, Florida] prothorax
with weakly developed prosternal keel and pinch, line
= 0.60 mm; e.) ventral and f.) lateral view of
Ischyrus scutellaris Gorham [Mexico, Yucatan]
prothorax with strong keel and pinch, line = 0.40 mm;
g.) ventral and h.) lateral view of Ischyrus n. sp. 7
[Panama] prothorax with prosternal keel swollen above
pinch, line = 0.44 mm.

I use the term "prosternal plate" in reference to the

surface of the prosternum between the coxal lines (Fig. 9).

This "plate" is most often flat, but can be slightly

convex. The plate shape varies throughout the genus (Fig.

11), from semicircular (wider than long) to elongate,

parallel-sided (longer than wide).

The length of the procoxal lines varies from species

to species. I use three phrases to describe the length of

these lines in relation to the procoxae: surpassing coxae,

barely surpassing coxae, not surpassing coxae. The phrase

"surpassing coxa" (Fig. lib) indicates the line passes

beyond an imaginary line drawn between the anterior edge of

the procoxae. The phrase "barely surpassing coxa" (Fig.

lla, 11c) indicates the line passes beyond the point where

the line in front of coxa begins, but does not pass beyond

an imaginary line drawn between the anterior edge of the

procoxae. The phrase "not surpassing coxa" (Fig. lid)

indicates where the line stops where the line in front of

procoxae begins, well before the imaginary line.

Many species have sexual dimorphism on the prosternum

in one or two forms. The majority of the species studied

have a differing number, or varying development, of foveate

punctures in front of the procoxa. In these species,

females have more numerous or distinct foveate punctures

than the males (Figs. 12-14), the opposite of Delkeskamp's

(1959) observations of certain African Dacninae.

a b c d

Figure 11. Prosternal plates showing procoxal line
shapes and anterior development, line = 1.0 mm;
a.) Ischyrus proximus Lacordaire, barely
suprassing coxa; b.) I. n. sp. 7, parallel-sided
and surpassing coxa; c.) I. n. sp. 5, semicircular
and barely surpassing coxa; d.) I. duponti
Lacordaire, not surpassing coxa. Imaginary line
(dashed) included for referencing anterior edge of
procoxae in determining procoxal line development.

Figure 12. Prosternal sexual dimorphism in puncture
development. Male Ischyrus n. sp. 7 [Panama]
prosternum: a.) ventral view, line = 0.38 mm; b.)
lateral view, line = 0.50 mm; c.) ventral view of
prosternal-pronotal epipleural suture, line = 0.17 mm;
d.) prosternal punctures in front of procoxa, line =
0.04 mm. Female Ischyrus n. sp. 7 [Panama]
prosternum; e.) ventral view, line = 0.43 mm; f.)
lateral view, line = 0.50 mm; g.) prosternal punctures
in front of procoxa, line = 0.04 mm.

Figure 13. Prosternal sexual dimorphism in puncture
development and lateral expansion. Male Ischyrus
incertus Lacordaire [Mexico, Chiapas] prosternum: a.)
ventral view, line = 0.75 mm; b.) lateral view, line =
0.50 mm; c.) ventral view of laterally expanded
prosternal-pronotal epipleural suture, line = 0.17 mm.
Female Ischyrus incertus Lacordaire [Panama]
prosternum; d.) lateral view, line = 0.50 mm; e.)
ventral view of prosternal-pronotal epipleural suture,
line = 0.25 mm.

Figure 14. Prosternal sexual dimorphism in puncture
development and lateral expansion. Male Ischyrus
scutellaris Gorham [Mexico, Yucatan] prosternum: a.)
ventral view, line = 0.60 mm; b.) ventral view, line =
0.30 mm; c.) lateral view of prosternal expansion,
line = 0.12 mm. Female Ischyrus scutellaris Gorham
[Mexico, Yucatan] prosternum; d.) ventral view, line =
0.50 mm; e.) ventral view of prosternal-pronotal
epipleural suture, line = 0.17 mm.

In a few species, males have the prosternum expanded

laterally, obscuring the prosternal-pronotal epipleural

suture (Figs. 13-14). The extent of the expansion appears

consistent in all specimens of a species, but is variable

among species. It can be a small expansion (Fig. 13), or

it can nearly cover the entire pronotal epipleuron (Fig.



The mesosternum has few useful characters. The length

of the mesosternal lines in relation to the distance

between them, along with the meso-metasternal suture shape,

is useful in grouping related species. This suture can be

truncate (Fig. 15a), sinuate (Fig. 15f), or broadly sinuate

(Fig. 15c).


The metacoxal lines usually extend posteriorly away

from the medial side of the mesocoxa towards the hind angle

of the metasternum (Fig. 9, 15). These lines are variable

in shape and length.

Anteriorly, the metacoxal lines can stop near the

mesocoxa or continue along the meso-metasternal suture,

often meeting at the middle. The shape of the line between

the coxae varies from species to species and is useful in

grouping related species. The term recurvedd" is used to

describe a line that curves away from the meso-metasternal

suture (Fig. 15c-f). Medially, these lines can take

several forms: absent, not recurved nor meeting medially


d e f

Figure 15. Meso- and metasternum showing coxal line
development, line = 0.5 mm: a.) Ischyrus
auriculatus Lacordaire, not recurved or meeting at
middle; b.) I. aleator Boyle, not recurved and
meeting at middle; c.) I. undulatus Gorham,
recurved and meeting at middle; d.) I. n. sp. 13;
e.) I. distinguendus Lacordaire, Mc = mesocoxa, Ms
= mesosternum, Mt = metasternum; f.) I. n. sp. 3.

(Fig. 15a); not recurved meeting in a straight line (Fig.

15b); meeting with a series of punctures or undulations

(Fig. 15c); meeting as a single tooth (Fig. 15e); meeting

with two widespread teeth (Fig. 15d); or meeting with many

teeth (Fig. 15f).

The mesosternal line behind the mesocoxa is variable

in its structure from species to species. It can be a

simple line (Fig. 16a) which is single-sided, a groove

(Fig. 16b) which is double-sided, or a groove which is

notably deeper on one end and leads into a large pit (Fig.

16c). This pit is most often present at the medial end of

this line, but the groove can be deepened at the lateral

end (for example, I. n. sp. 13).

First Visible Abdominal Sternite

The coxal lines on the first visible abdominal

sternite extend posteriorly from the medial side of the

metacoxa. They are variable in length from specimen to

specimen and are of little use in determining species.

This first visible abdominal sternite can be rounded,

broadly rounded or truncate between the metacoxa at the

junction with the metasternum.

Male Genitalia

The internal sac of the male genitalia is held

inverted within the median lobe (Fig. 17a). During

copulation, the internal sac is everted, exposing any

microstructure and extending the flagellum (Fig. 17b). The

median lobe, internal sac, and flagellum are the true


Figure 16. Metasternal line posterior to mesocoxa: a.)
simple line on Ischyrus proximus Lacordaire [Mexico,
Chiapas], line = 0.75 mm; b.) groove on Ischyrus q.
quadripunctatus (Olivier) [USA, Florida] line = 0.38
mm; c.) groove with pit at medial end on Ischyrus n.
sp. 3 [Panama], line = 0.28 mm.

Figure 17. Male genitalia of Ischyrus q. quadripunctatus
(Olivier), line = 0.66 mm; a.) internal sac inverted
as held within the body; b.) internal sac and
flagellum everted as during copulation; F =
flagellum, Is = internal sac, Ma = sclerite for
muscle attachment at anterior end of flagellum, Ml =
medial lobe, Ms = median strut.

intromittent organs and show the majority of species

specific characters. For additional insight into the

genitalia of Coleoptera, I recommend the following:

Lindroth 1957; Sharp and Muir 1912; Skelley 1993; Snodgrass

1957; Tuxen 1970; Verhoeff 1895; Williams 1945; and Wood


The median lobe is a simple tubular structure that is

curved and laterally flattened. The degree of curvature

varies from species to species and can be slightly curved

to arched. The shape of the median lobe's posterior end

varies, and can be truncate, rounded, or narrowed and then


The internal sac occasionally has pigmented areas,

which are patches of microspinules. These can be large

lightly pigmented patches of widely scattered

microspinules, or small dark paired patches. These patches

are known in only a few species.

I found the shape of the sclerite for muscle

attachment at the flagellum's base to be important in

species recognition. The sclerites are all basically U-

shaped, but with many variations. Just posterior to this

sclerite is a pigmented section. This section of the

flagellum is often variable in shape and curvature. A

close study showed it to be flexible, like cartilage. The

shape of this structure was not used to distinguish species

because it can vary from specimen to specimen. The

flagellum is variable throughout the genus: long,

cylindrical, and hair-like; flattened and ribbon-like; or

straight and rigid. The tip of the flagellum can be

pointed or flared.

Female Genitalia

Female genitalia (Fig. 18) varied little from species

to species. Structures had proportions which varied, but

species recognition based on female genitalia was not

possible with any degree of confidence. The sclerotized

spermatheca showed some variation in shape which could be

useful in studies of higher categories.

The spermatheca consisted of two parts; the head and

tail. The head is the large bulbous, terminal structure,

which varies in shape from circular to kidney-shape. Many

species have spermathecae with a top-knot (bump on the

head), variable in size and occasionally in position. The

spermatheca tail is a sclerotized section of the duct

extending from the spermatheca's head to the genitalia.

The shape and thickness of the tail is variable, but

similar in related species.

Materials and Methods


Dry preserved specimens were borrowed from many

sources (institutions and individuals) during this

revision. Appendix B lists these sources with their coden

(mostly from Arnett et al., 1993) used throughout this





a T8

Figure 18. Female genitalia of Ischyrus q. quadripunctatus
(Olivier), line = 1.0 mm: a.) spermatheca; b.) ventral
view; c.) dorsal view; A9 = abdominal segment IX, H =
head of spermatheca, P1 = proctigeral lobe, S8 =
abdominal sternum VIII, sS8 = straps appendant to
abdominal sternum VIII, sT8 = straps appendant to
abdominal tergum VIII, St = styli, T8 = abdominal
tergum VIII, T = tail of spermatheca, Tk = top-knot on
spermathecal head.

Locating Types

In most taxonomic research the investigators must

study material seen by the describer of a species in

creating the description. These specimens are the

reference point for the name. Many descriptions were

poorly done, or lack specific details needed to identify

additional specimens. The history of each "type" specimen

becomes important in locating it or discovering if it still

exists. Modern researchers must record the depository of

specimens studied. Early researchers did not always do

this. Horn and Kahle (1935-1937) and Sachtleben (1961)

stated the location or fate of many collections and can be

helpful in locating a specific specimen.

For New World Erotylidae the majority of early type

material can be found in three places: the Museum National

d'Histoire Naturelle, Paris (MNHN); the Crotch Erotylidae

Collection, University of Cambridge, U.K. (CUMZ); and the

Natural History Museum, London (NHML).

Many of the nomina nuda in Dejean's catalogs (1836,

1837) and collection, were validated by Lacordaire because

he acquired Dejean's Erotylidae (Horn & Kahle 1935-1937)

and used Dejean's names in his descriptions. Horn & Kahle

indicate that Lacordaire's collection was divided and

deposited in various European museums. I have been unable

to find all of Lacordaire's Erotylidae, but he studied

specimens of several other collectors whose material can be

found in two places: the Crotch collection (CUMZ); or the

Oberthir collection (MNHN).

Many of Lacordaire's species were described from the

Dupont collection. Horn & Kahle indicate that the Dupont

collection was divided with some of the material being

deposited in the collections of G. V. Mniszech and R.

Oberthir. Nicole Berti at the Museum National d'Histoire

Naturelle, Paris (in litt.), stated that the Oberthur

collection, including the Mniszech collection, is at the

MNHN, and that Oberthir indicated on the back of a box that

specimens studied by Lacordaire are in the collection of

Mniszech. For Ischyrus, the specimens labeled "Type" from

this collection matched the original descriptions in both

morphology and label data. Most specimens in this

collection do not have "Type" labels, but they are

potentially type material and should be considered in

subsequent type designations for Lacordaire species.

Lacordaire also studied specimens from the collections

of L. A. A. Chevrolat and L. J. Rieche. These erotylid

collections, and others, were acquired by G. R. Crotch.

Crotch's Erotylidae collection, at the Cambridge University

Museum of Zoology, is rich in types. In this collection,

label data indicate which specimens are types, and often

from whose collection they came. The Ischyrus specimens

labeled "Type" fit the original descriptions, label data,

and collection of origin.

The Natural History Museum, London, (formerly known as

the British Museum of Natural History) houses the specimens

studied in the Biologia Centrali-Americana (Gorham 1887-


Tracking one specimen illustrates that it is not

always a simple matter. The type specimen of Ischyrus

quadripunctatus (Olivier), the generotype of Ischyrus, was

not studied by Boyle (1956) in his family revision of

America north of Mexico. Olivier (1791) stated that the

specimen was in the collection of M. Francillon. Horn and

Kahle (1935-1937) state that the Francillon collection was

divided and deposited in the Natural History Museum,

London, and the Hope Entomological Collections, University

of Oxford, U.K. I visited the Natural History Museum and

found no specimen which could be the type. The curator of

the Hope Entomological Collections, G. C. McGavin, wrote

that the majority of their part of the Francillon

collection was sent to the (Alexander) MacLeay Museum,

Sydney, Australia, in 1818. The curator of the MacLeay

Museum, D. S. Horning, Jr., wrote that they do have

specimens from the Francillon collection, including some

from the locality stated in Olivier's description. But, he

would be unable to look for the specimen until his recent

injury had healed. Thus, I still do not know if the

specimen studied by Olivier exists.


Specimens of the genus Ischyrus can be found feeding

on their host fungus. Based on the number of specimens

known for most species, we still do not know where to look.

Most specimens appear to have been haphazardly collected,

even those collected in light traps.

No definitive statement can be made about where to

look for, or how to collect, members of this genus. I have

collected various species of Ischyrus and related genera by

using a beating square on dead sticks at night. Sticks,

limbs, branches, etc., which produced the most specimens

were either still on the tree, or on the ground, but

suspended above the surface. The only known hosts are

prostrate white fungi which seem to prefer dead suspended


Much work remains to be done in understanding the

biology of this genus and the family. (See the Biology

section under the Generic Account for additional comments.)


Specimens were studied under a binocular dissection

microscope, Unitron ZSB, with a zoom-magnification of 0.7x-

4.5x and 20x ocular lenses. A Hitachi S-570 scanning

electron microscope was used. Although useful in seeing

and understanding many of the minute characters, it was not

an essential part of this study. I made an effort to base

species descriptions and key characters on those visible at

low magnifications.


Adult specimens often needed to be cleaned before

surface structures could be studied. This was accomplished

by brushing the specimen with a small soft-bristle brush

dipped in ethyl acetate or alcohol. Ethyl acetate was also

used to degrease badly soiled specimens. If the mouthparts

were badly soiled, the specimen was dipped in warm water to

loosen the dirt, and to relax the specimen before brushing

the dirt away. On rare occasions specimens were so badly

soiled that they were totally relaxed, cleaned, and


European-style card mounting made it impossible to

study the ventral surfaces without removing the specimen

from the card. The solvent used to soften the glue

depended on what glue was used. The following series of

chemicals was used until one dissolved the glue: water, 70%

isopropanol, 80% ethanol; ethyl acetate. Rarely did the

specimen require treatment with all of these, but

occasionally a specimen needed to have the glue manually


I dissected many genitalia for further study.

Specimens were chosen from across the distributional range

of the species and from those showing variation in external

characters. Each specimen was put into a weak solution of

hot detergent water and allowed to sit from one hour to

overnight. Once relaxed, the specimen was carefully held

between the thumb and forefinger under the dissecting

microscope. With a pair of jewelers forceps, the elytra

were lifted just enough to slip one side of the forceps

underneath and the abdomen was grasped on a side. In this

way, the specimen was held and the remainder of the body

was not effected by the dissection to follow.

The abdominal tergites (membranous) and underlying

muscle masses were separated from the visible sternites on

the side not held by the forceps. This was done with a

bent-tipped minute attached to a small wooden toothpick.

Once loosened, the forceps were moved to hold only the

sternites of the side just separated, and the same

operation performed on the second side. After these

separations were complete the tergites and underlying

muscle masses were removed with a second pair of forceps.

This technique allows the visible abdominal sternites to

remain attached; the specimen appears intact.

The removed muscle masses containing the genitalia,

and terminal segments of the abdomen, were cleaned and

cleared in a warm 10% potassium hydroxide (KOH) solution,

and the remaining unwanted tissues were removed manually

with forceps. The genitalia were rinsed in 70% isopropanol

or water and stored in glycerin in genitalia vials

associated with the appropriate specimen. Genitalia vials

are small plastic or glass vials that can be placed under

the pinned specimen, with the pin piercing the stopper.

Detailed study of these genitalia rarely required more

magnification than the dissecting microscope allowed. The

genitalia were studied in glycerin, and moved into various

positions to see the shape of the muscle attachment at the

anterior end of the internal sac. The shapes of this

structure and the flagellum were important in solving many

of the species problems. When finished, the genitalia were

returned to the genitalia vial and pinned under the

appropriate specimen.

The stridulatoryy files" were not studied for many

species since this required removing the head from the

body. This type of dissection destroyed the specimen, and

I was not willing to sacrifice the few specimens available

for most species.

Illustrations were made with the use of a glass-grid

insert placed in an ocular of the dissecting microscope.

The imposed grid on the specimen was used as reference and

the drawing was made on a piece of grid paper. It was

necessary to make various adjustment to each of the

drawings, because the curvature of the lenses produced

distortions. This was most apparent when comparing the

finished pencil drawing and the specimen without the aid of

the microscope. The drawings were then traced in India ink

onto tracing paper with a 000 Koh-i-nor Rapidograph

technical pen, scanned into electronic form using a Hewlett

Packard Scanjet IIP, finished using CorelDRAW* 2.01 (a

computer graphics program) on a Unisys 486 personal

computer, and printed with an Apple LaserWriter" II.

Habitus drawings lack legs and antennae for several

reasons. First, the legs are of little use in determining

species. The antennae need to be illustrated side-by-side

for close comparisons. Adding these structures doubles or

triples the time to do an illustration. Lastly, by

omitting these structures, the habitus drawings can be

placed closer together, requiring less space and fewer


In plotting distribution maps, many specific

localities were not found because of poor label data. If

the information was adequate enough find the general area,

an open symbol was placed on the map in the general area.

Specific localities are shown with solid symbols. If label

data were vague and there was already a plotted locality in

the general area, an additional symbol was not added.

Questionable records are plotted with a question mark "?".

Color Pattern Problems

Species level decisions have historically been based

simply on color and color patterns. Museum specimens vary

in the shades of orange because of age, killing agent, and

preservation technique. Because of this, the exact color

is of little use in species determination.

The color pattern is most important in determining

species, but care must be taken in analyzing differences.

The specimen(s) in question must first be placed within the

proper section of the genus. This was done by using

morphological and genitalic characters. Many recently

described species were compared to an unrelated species in

the original description. This made determinations based

on the literature impossible, and the type specimens had to

be studied.

A different appearing color pattern did not

necessarily mean the specimen was a different species. For

example, a species may have two spots on each elytron.

When these spots are enlarged, they blend together and form

a band. Differences based on changes in pattern due to the

spot size generally were not specific.

In other cases, a spot which varied in its location,

generally indicated a specific difference. For example, in

two closely related species the only color pattern

difference is that one species has a humeral spot touching

the base and the other has a subhumeral spot well removed

from the base. In I. scriptus, I. proximus, I. palliatus,

and I. incertus, the relative position of the pronotal

spots and the shape of the circle they form is useful in

determining species.

Written descriptions cannot convey the exact details

of these patterns the way an illustration does. Every

species and many variations are here illustrated. In some

cases the differences are subtle, but they are constant and

correlate with other morphological differences. Care

should be taken when comparing any specimen to these

illustrations because of color pattern variations mentioned

above, and ones not yet known.

Studying series of specimens from a large geographic

range has allowed me to observe geographic variations in

color patterns that were once considered specific. One

such character is the color of the head, which can be red,

black, or with some variation of both. In only a few

cases has this variation been more than a clinal or

subspecific difference.

The term "pattern" was used for variations of a color

pattern in situations where previously described species

were found to be part of a dine. These "patterns" were

maintained because they still had some relation to a

geographic range. The "pattern" name is the specific name

that once applied to that pattern, or a name was applied

if that "pattern" was not previously described. New

"pattern" names were applied only if specific names already

existed for other patterns (see I. quadripunctatus and I.

scriptus). These named "patterns" have no nomenclatural


Another general trend is the change of elytral

patterns from north to south. Many species have solid

bands with smooth edges in the north; moving south, these

edges become more and more sinuate. Some even develop into

stripes as the sinuate edges on both sides of the band

meet. Many species from mid-South America have striped

patterns. In contrast, the majority of northern species

have banded patterns. This is best illustrated with I.

quadripunctatus, I. scriptus, and their variations. This

trend may indicate mimetic relationships among species.

Rules of Thumb

In determining the taxonomic status of various names,

and in naming new taxa, several general rules were followed

which require some explanation.

Many species are variable in color pattern over their

geographic range. This is illustrated in several species

where adequate series have been studied. Certain color

patterns are known from only a few specimens, often from

scattered localities. If two specimens have different, but

basically similar color patterns and their morphology

(including the genitalia) is similar, they are considered

variations of a single species.

In other cases a radical color pattern difference is

observed, but the genitalia are incomparable (i.e., male

vs. female). These are considered variations of a single

species, and are discussed under the most closely related

described species, noting the variations and their

taxonomic status.

If a previously described species was a member of

several patterns in a dine, that name was synonymized

under the senior name and discussed in the species account.

Consistent morphological differences correlated with

color pattern differences are considered to be specific,

and these taxa are described. New species are simply

numbered, because of problems with nomeclatural priority,

and names will be proposed when published.

The lack of series in many species indicates that

there is much to be discovered in this genus. Several of

the species discussed here may actually represent

complexes. Because of inadequate material these problem

taxa are left unresolved and are discussed under the

appropriate species account.


The genus Ischyrus is composed of 42 North and Central

American species, including 16 previously undescribed;

leaving 30 additional described species in South America.

A total of 3741 North and Central American specimens was

studied (2890 I. quadripunctatus) and 363 were dissected.

The 148 figures, key, appendices, and descriptions are

provided to complete this revision.


Ischyrus Lacordaire 1842:89-131.
Micrischyrus Alvarenga 1965:86.

Type Species. Erotylus quadripunctatus Olivier
1791:431,437. Subsequent designation by Crotch
1873a:353; 1873b:144.

Diagnosis. Characterized by having coarsely faceted

eyes, triangular mentum, short ocular stria not surpassing

anterior angle of eye, undilated tibia, and semicircular or

trapezoidal antennomere IX.

Description. Length 3.5 9.9 mm. Body shape

parallel-sided, to elongate, or ovoid, slightly flattened to

convex dorsally; microreticulation, surface dull to shining;

unicolorous brown to variously banded or spotted, yellow-

orange with black pattern.

Head with ocular striae generally ending at or before

anterior angle of eye, rarely extending onto epistome at

base of antenna; frons often with an impression at each side

near base of antennae; epistome wedge-shaped, generally with

truncate apex; epistome punctures generally denser than

punctures on vertex. Eye large, bulging from side; facets

coarse (Fig. la), varying in size throughout the genus,

rarely fine.

Antenna surpassing middle of pronotum, often reaching

basal 0.25; antennomere I large, elongate; antennomere II

circular, ball-like, length = 0.5 x antennomere I;

antennomere III elongate, length equal to next 2 to 4

segments combined; antennomeres IV to VIII length subequal

to width, length rarely more than 1.5 x width; antennomeres

IV to VII rounded at ends; antennomere VIII edged and angled

apically; antennomeres IX to XI form a loose club;

antennomeres IX to X 3 to 4 x wider and 1.5 to 2 x longer

than antennomere VIII; antennomere IX semicircular to

trapezoidal, rarely triangular (Fig. 6); antennomere X

crescent-shaped to trapezoidal; antennomere XI transversely

elongate-oval to circular; antennomeres X-XI often


Mandibles each with two finger-like teeth and a large

prostheca bearing many inwardly pointing setae. Maxilla

with lacinia bearing an apical tooth, often bifid (Fig.

19b); terminal segment of palp triangular or securiform,

width = 1 to 3 x length. Labial palpi vary from squared or

circular to securiform, width = 1 to 2 x length (Fig. 7).

Mentum with a pore on each side in front of basal corner;

mental plate triangular, rarely longer than wide; ridge

surrounding plate often raised laterally giving mentum a

three prong crown-shape, medial prong (medial ridge

extension) variously shaped, protruding or not (Figs. 8,

19a). Postmandibular lobes present, broadly rounded,


T --\

o M

a b

Figure 19. Ischyrus q. quadripunctatus (Olivier)
a.) labium and b.) left maxilla ventral
view, line = 0.25 mm: M = mentum, Lp =
labial palp, Mp = maxillary palp, T = bifid
tooth of lacinia.

Figure 20. Ventral view Ischyrus q. quadripunctatus
(Olivier) [USA, Florida] head and prosternum, line =
0.50 mm.

forming inner side of groove next to the eye for reception

of antennomeres II to III (Fig. 20).

Pronotal disc evenly rounded; sides variably arched

inwardly toward eyes; anterior angles closer together than

posterior angles; anterior edge not margined between eyes;

anterior angles forwardly produced, making anterior edge

concave; base sinuate, not margined, lobed at middle, with

group of large punctures at each side. Scutellum

pentagonal, wider than long.

Elytra with sides parabolically rounded to apex; 7 to 9

stria evident by rows of punctures, lacking at humerus and

extreme apex, rarely impressed or missing; intervals

flattened, often with minute punctures; base rarely

margined; elytral epipleuron widest at base, strongly

narrowed at hind coxae, gradually folding under to apex

(Fig. 9); some elytral punctures each with a small

protruding seta, visible in profile.

Prosternum usually keeled, margined and constricted

(pinched) at front (Figs. 10, 20); sternal plate shape and

proportions variable (Fig. 11); lines anteriorly converging

or parallel, rarely surpassing front of procoxa, lines not

continuous around coxae (except n. sp. 1); posteriorly

prosternum truncate or slightly concave, not margined.

Mesosternal lines parallel or anteriorly divergent,

straight or arched; plate square or transversely

rectangular; posteriorly sinuate or truncate.

Metasternal lines extending onto disc from inside of

mesocoxa toward posterior angle of metasternum, rarely

continuous around mesocoxae; variable in length, up to 0.5

distance to posterior angle; line behind mesocoxae variably

impressed or grooved, occasionally with pit (Fig. 16).

Legs with femora slightly swollen, complete margin on

inner surface (Fig. 21); tibia straight, almost parallel-

sided, slightly widened toward apex; tarsi


Abdominal coxal lines present, short; rarely continuous

around metacoxae.

Male genitalia with median strut length variable, equal

to or larger than median lobe; internal sac can bear patches

of spinules; flagellum varying in length and thickness, with

sclerotized muscle attachment at base, non-slerotized

section at base flexible; lateral lobes of tegmen generally


Female genitalia with straps appendant to abdominal

segment VIII; abdominal segment IX elastic, length variable;

flattened plate-like proctigeral lobe; apical segment of

coxite with slender styli (Fig. 18). Proportions of these

stuctures vary little throughout the genus. Spermatheca

sclerotized, shape of head and tail variable, occasionally

with a top-knot (Fig. 18).

Stridulatory files often present at the base of the

head (Fig. 22).

Figure 21. Ventral view of meso-femur: a.) Ischyrus q.
quadripunctatus (Olivier) [USA, Florida] with posterior
margin, line = 0.50 mm; b.) Oocyanus flavitarsis
(Lacordaire) [Cuba] lacking posterior margin, line =
0.60 mm.

* q.'~S

Figure 22. Ischyrus q. quadripunctatus (Olivier) [USA,
Florida] occipital region of head showing stridulatory
file (arrow): male with stridulatory file, a.) line =
0.38 mm, b.) line = 0.08 mm; c.) female lacking
stridulatory file, line = 0.15 mm.

Sexual dimorphism often present. Males of some species

have the prosternum laterally expanded onto the pronotal

epipleuron; not expanded in females (Figs. 13-14). Males of

many species have fewer, or less distinct, punctures on the

prosternum in front of the procoxae (Figs. 12-14).

Distribution. This genus is restricted to the New

World, where it is widespread, occurring from southeastern

Canada near the St. Lawrence Seaway and southeastern North

Dakota through the eastern U.S. and southern Arizona,

Mexico, Central America, the West Indies, into South America

to northern Argentina.

Bioloav. The life history of this genus is basically

unknown. Only one species has its larva described; the type

species I. q. quadripunctatus (Olivier) (see Weiss 1920,

Skelley 1988b, Chapuis & Candeze 1855, Chapuis 1876). The

following is based on published accounts of this species, a

few bits of information taken from label data, and personal

communications and observations.

The larva of I. q. quadripunctatus has well developed

dorsal sclerotization with short spines. It is unusual in

that the pronotal sclerotized area is broken into parts

appearing like false eyes (Fig. 23). Members of a related

genus, Oocyanus Hope, have a similar set of "eye-spots".

This peculiarity could be of adaptive significance in

warding off predators. Both of these larvae have been found

feeding exposed on prostrate white fungus growing on dead

wood (personal observations). Other larvae of the

Figure 23. Ischyrus q. quadripunctatus (Olivier) larva
[USA, Florida], line = 4.0 mm.; a.) lateral view; b.)
dorsal view of head and thorax.

_ _

Erotylidae are burrowers in fungi (some Triplacinae,

Dacninae) or are surface feeders (some Erotylinae). The

surface feeding Erotylinae are often protected by a covering

of large spines and often have color patterns; whereas

burrowing species lack these spines and patterns (see

Roberts 1958; Costa, et al. 1988; and Lawrence 1991, for

illustrations of various erotylid larvae).

Ischyrus q. quadripunctatus has been collected on a

white resupinate polypore fungus, Oxyporus latemarginatus

(Dur. & Mont. ex. Mont.) Donk, also known as Poria ambigua

Bres. (Skelley, et al. 1991). Richard Leschen (pers. comm.)

collected I. proximus on Schizopora paradoxa (Fr.) Donk in

Costa Rica, also a white resupinate polypore. Both of these

fungi are white rot fungi of wood.

Adults have been taken by general collecting methods;

in leaf litter, under bark, sweeping vegetation, etc. Many

specimens have been taken at light, suggesting nocturnal

activity. This is also indicated by the large eye facets

present in members of this genus. Using a beating square at

night, I collected several species of Ischyrus and other

related genera on small dead limbs both on the ground and

hanging from the trees.

Several species have pits on one of the thoracic

sternites, for example; I. undulatus and I. n. sp. 3 on the

metasternum behind the mesocoxa, and I. n. sp. 1 on the

prosternum. These pits occur on both sexes of the species

and show no sexual dimorphism in their development. Their

function is not known, but they could be used for structural

support, muscle attachment, areas for glandular secretion,

or mycangia (Crowson 1981).

Etymoloav. Ischyros: Greek for strong, mighty,

excessive (Brown 1985). Possibly named in reference to the

strongly clubbed antennae or pronounced color patterns.

Gemminger and Harold (1876) indicated that the name Ischyrus

means "validus".

Remarks. Although Boyle (1956:110) stated that

Ischyrus lacks teeth on the lacinia; this is incorrect. The

tooth illustrated (Fig. 19) is located in a dense patch of

setae and is difficult to see.

Ischyrus Lacordaire appears most closely related to

Megischyrus Crotch, Callischyrus Crotch, and Oocyanus Hope

in having a triangular mentum, loose antennal club,

strongly microreticulate body surface, and in basic color


Ischyrus differs from Oocyanus in having the femora

margined along the inner side where the tibiae meet the

femora (Fig. 21a); this margin is lacking in Oocyanus (Fig.

21b). Callischyrus differs from Ischyrus in having the eyes

finely faceted and the ocular stria surpassing the antennal

base; in Ischyrus the eyes are coarsely faceted and the

ocular stria at most touch the antennal base. Megischyrus

differs from Ischyrus in having a larger body size (greater

than 11 mm) and in having antennomere IX triangular (Figs.

6n-o); in Ischyrus the body size is smaller (less than 10

mm) and antennomere IX is semicircular or trapezoidal,

rarely triangular.

References. Alvarenga 1965:85; Arnett 1963:817-821;

1985:341-342; Blackwelder 1945:465; Boyle 1956:132-137,128;

Chapuis 1876:35-38; Crotch 1873a:353-354; 1873b:144;

1876:426-433(50-57); Curran 1944:1-5; Edwards 1949:94;

Gemminger & Harold 1876:3690-3691; Germar 1843:133; Girard

1873:820; Gorham 1887:39-45; Kuhnt 1909:55,57,61-64;

1911:42-44; Lacordaire 1842:89-131; LeConte & Horn 1883:124;

Leschen 1991:180, 192; Mader 1942:171,195-196; 1951:209-210;

Neave 1939-1940:790; Pallister 1955a:4; 1955b:6-7; Seidlitz

1891:288; Skelley 1988b:60.


This key was built using characters visible under low

magnification, without dissection. Several species appear

in the key more than once, beacuse some characters are

variable or have an intermediate state on some species.

Couplet 3 is the best example of a character that can be

difficult to interpret. If a specimens does not adequately

key, or does not match what it does key to, then try the

other choice in the couplet.

1. Antennomere IX triangular, sides straight, as long or

longer than wide (Figs. 6k, 6n-o); body convex dorsally

(Fig. 2b) ........................................... 2

1'. Antennomere IX trapezoidal to semicircular, sides angled

or rounded, generally wider than long (Figs. 6a-j, 61-

m); body parallel-sided, elongate or ovoid; flattened

above (Fig. 2) ...................................... 3

2.(1) Pronotum with 2 free spots (Fig. 24). .

.............................. vespertilio Lacordaire

2'. Pronotum with central stripe (Fig. 25). ..... n. sp. 1

3.(1') Antennal club segments distinctly asymmetrical;

antennomere XI larger (wider or longer) than

antennomere X (Fig. 6a-f) ........................... 4

3'. Antennal club segments symmetrical; antennomere XI size

variable; if appearing asymmetrical, antennomere XI


24L 25 26 27

I 1

28 29 30 31

32 33 34 35

Figures 24-35. Dorsal habitus, line = 1.0 mm: 24.)
Ischyrus vespertilio Lacordaire; 25.) I. n. sp. 1;
26.) I. n. sp. 2; 27.) I. distinguendus Lacordaire;
28.) I. insolens Crotch; 29.) I. scriptus (Olivier)
"northern"; 30-31.) I. scriptus "southern"; 32.) I.
bogotae Crotch; 33.) I. incertus Lacordaire; 34.) I.
proximus Lacordaire; 35.) I. angularis Lacordaire.

equal in size or smaller than antennomere X (Fig. 6g-

m). .............................................. 19

4.(3) Pronotum without free spots ........................ 5

4'. Pronotum with free spots ............................. 6

5.(4) Pronotum with a central black stripe and red sides, no

basal spots (Fig. 26). ................... n. sp. 2

5'. Pronotum red with three basal spots only (Fig. 27). .

............................ distinguendus Lacordaire

6.(4') Pronotal hind angles with a dark marking, black of

lateral margin encroaches upon the side ............. 7

6'. Pronotal hind angles without distinct dark markings .. 8

7.(6) Pronotum with 4 free spots in a transverse arc; 2

central spots well separated from the base (Fig. 28). .

..................................... insolens Crotch

7'. Pronotum with 2 basal, 2 central, and 2 anterior spots

forming a circle; 2 central spots close to or connected

with the base (Figs. 29-31) ...... scriptus (Olivier)

8.(6') Pronotum with 2 free spots; 2 basal spots rarely free

or weakly touching margin; if appearing free, then

spots separated from base by less than their diameter

(Figs. 29, 32-35). .................................. 9

8'. Pronotum with 3-4 free spots; if 4, then central spots

separated from base by more than their diameter (Figs.

37-47). .. .......................................... 14

9.(8) Pronotum with spots on anterior margin. ......... 10

9'. Pronotum without spots on anterior margin ......... 13




\ 7,



Figures 36-47. Dorsal habitus, line = 1.0 mm: 36.) Ischyrus
septemsignatus Gorham; 37.) I. tripunctatus Crotch;
38.) I. frontalis Lacordaire; 39.) I. frontalis var.;
40.) I. dunedinensis Blatchley; 41.) I. boucardi
Crotch; 42.) I. quadripunctatus chiasticus Boyle; 43-
47.) I. quadripunctatus quadripunctatus (Olivier); 43.)
I. q. q. "quadripunctatus"; 44.) I. q. q. graphicsus;
45.) I. q. q. "subcyindricus"; 46.) I. q. q.
"Antillean"; 47.) I. q. q. "banded-leg".





\% 44

10.(9) Pronotum with 1 large basal spot (Fig. 32). .

...................................... bogotae Crotch

10'. Pronotum with 2 basal spots ........................ 11

11.(10') Antennomere XI equal in size to antennomere X (Fig.

61); femur black; elytra with weak microreticulation,

strongly shining; pronotal spots forming a transversely

elongate ellipse (Fig. 33) ........ incertus Lacordaire

11'. Antennomere XI larger than antennomere X (Fig. 6c);

femur red or black; elytra with dulling

microreticulations; pronotal spots forming a circle,

longitudinally elongate circle, or rarely a weak

transverse ellipse (Figs. 29-31, 34) ............... 12

12.(11') Femur red with dark knee; humeral spot free from

scutellar spot; elytral epipleural fold black,

occasionally pale in general specimens; pronotal spots

form a circle or weakly transversely elongate ellipse

(Figs. 29-31) ..................... scriptus (Olivier)

12'. Femur and scutellum black; humeral spot connected to

scutellar spot; elytral epipleural fold red, at least

at base, rarely dark; pronotal spots forming a

longitudinally elongate ellipse (Fig. 34)..............

................................. proximus Lacordaire

13.(9') Elytra with central band and apical spots connected

to suture (Fig. 35) .............. angularis Lacordaire

13'. Elytra with central band and apical spots not reaching

the edge (Fig. 36) .............. septemsignatus Gorham

14.(8') Pronotum with 3 free spots ..................... 15

14'. Pronotum with 4 free spots ........ ................. 17

15.(14) Central elytral band broken into spots .......... 16

15'. Central elytral band complete (Fig. 37) .

.. ............................ tripunctatus Crotch

16.(15) Lateral spot of elytra small, circular; Central

America (Figs. 38-39). ......... frontalis Lacordaire

16'. Lateral spot of elytra elongate, stripe-like; USA,

Florida (Fig. 40). dunedinensis Blatchley

17.(14') Maxillary palps narrow (Fig. 7f), longer than wide.

...................... quadripunctatus (Olivier). .18

17'. Maxillary palps wide (Fig. 7c), wider than long; (Fig.

41) ................................... boucardi Crotch

18.(17) Scutellar spots form an X-shaped mark; narrow band

of black at base of pronotum (Fig. 42) .

................... quadripunctatus chiasticus Boyle

18'. Scutellar spots not X-shaped, or if X-shaped then base

of pronotum with prominent tooth-like spots (Figs. 43-

47) ....... quadripunctatus quadripunctatus (Olivier)

19.(3') Metasternal line behind mesocoxa impressed with a

distinct pit near middle (Figs. 15c, 15f, 16c);

epistome angled at side, flat and sharp in profile;

face flat, usually lacking impressions; body

cylindrical ................. ...... ................. 20

19'. Metasternal line behind mesocoxa without pit, often

impressed (Figs. 15a-b, 15d-e, 16a-b); epistome angled

or not, often thickened at apex and rounded in profile;

face often with impressions; body often flattened .. 21

20.(19) Pronotum with 2 basal spots and a central stripe

connecting the base and anterior margin (Fig. 48). .

........................................ n. sp 3

20'. Pronotum without a central stripe, 4 free spots (Fig.

49). ................................. undulatus Gorham

21.(19') Color pattern lacking, uniformly colored, often

paler at lateral margins. ........................ 22

21'. With distinct color pattern ........................ 25

22.(21) Body with metallic blue sheen; strial punctures

present only at base and along sutural margin; Cuba

(Fig. 50) ...................... ............. n. sp. 4

22'. Body without metallic sheen; strial punctures present

over entire elytral disc ........................... 23

23.(22') Prosternum 2-3 times longer than the distance

between the procoxae (Fig. 11b); labial palps not

expanded, squared or rounded (Fig. 7k) ............. 24

23'. Prosternum at most 1.5 times longer than the distance

between the procoxae; labial palps expanded, securiform

(Fig. 7j); (Fig. 51) .......................... n. sp. 5

24.(23) Pronotal punctures distinctly larger laterally;

shiny black; parabolically rounded at sides (Fig. 52)

............................................ n sp 6

24'. Pronotal punctures same size throughout; dull brown;

parallel-sided (Fig. 53). .................... n. sp. 7

25.(21') Pronotum without free spots .................... 26

25'. Pronotum with free spots .......................... 32

56 57 58 59

Figures 48-59. Dorsal habitus, line = 1.0 mm: 48.)
Ischyrus n. sp. 3; 49.) I. undulatus Gorham; 50.) I.
n. sp. 4; 51.) I. n. sp. 5; 52.) I. n. sp. 6; 53.) I.
n. sp. 7; 54.) I. aleator Boyle; 55.) I. n. sp. 8;
56.) I. auriculatus Lacordaire; 57.) I. auriculatus
var.; 58.) I. ephippiatus Gorham; 59.) I. n. sp. 9.

26.(25) Prosternum not strongly constricted at anterior

margin, not produced in profile, not pinched (Fig.

10a). ............................................ 27

26'. Prosternum strongly constricted at anterior margin,

produced in profile, pinched (Fig. 10c-f). ......... 30

27.(26) Each elytron with 1 central stripe-like spot (Fig.

54) ..................................... aleator Boyle

27'. Elytra banded or spotted ........................... 28

28.(27') Pronotum entirely pale, elytra with small spots

(Fig. 55) .................................... n. sp. 8

28'. Pronotum black or with black markings, elytral marking

variable. ......................................... 29

29.(28') Elytra with distinct free spots, not banded (Fig.

25); metasternal coxal lines continuous behind

mesocoxae; line behind mesocoxa not impressed;

prosternal line in front of coxa a pit-like groove

(Fig. 9b) .................................... n. sp. 1

29'. Elytra distinctly banded (Figs. 56-57); metasternal

coxal lines not continuous behind mesocoxae, long; line

behind mesocoxa impressed, groove-like; prosternal line

in front of coxa simply impressed. . .

.............................. auriculatus Lacordaire

30.(26') Body stout, rounded laterally; pronotum entirely

black, or with anterior angles pale; each elytron with

a free basal spot .................................. 31

30'. Body parallel-sided, elongate; pronotum with pale

anterior angles and often with central red markings;

elytra lacking free basal spots (Fig. 58) .

.................................. ephippiatus Gorham

31.(30) Free scutellar and humeral spots in transverse line,

central elytral fascia not extended to apical quarter

(Fig. 59) ............................... n. sp. 9

31'. Free humeral spot located behind free scutellar spot;

central elytral fascia reaching apical quarter (Fig.

60) ......................................... n. sp 10

32.(25') Pronotum with 2 free spots and three basal spots (1

band-like free spot in collatinus), 3 basal spots not

including possible posterior angle spots ........... 33

32'. Pronotum with 2 or more free spots, possibly with three

basal spots, but not with the above combination .... 37

33.(32) Pronotal hind angle with a spot or widening in the

black margin; often with 2 weak black spots at anterior

margin of pronotum (Fig. 61) ................ n. sp. 11

33'. Pronotal hind angle without spot, lacking spots at

pronotal anterior margin ........................... 34

34.(33') Two free pronotal spots circular; scutellar spot

often broadly connected to elytral base ............ 35

34'. Free pronotal spot(s) transversely elongate,

rectangular; scutellar spot not connected to elytral

base ............................................... 36

35.(34) Apical elytral spot free; central band not reaching

lateral margin (Figs. 62-63) ............ pictus Gorham

35'. Apical elytral spot broadly connected to suture and

apex; central band complete, reaching lateral margin

(Fig. 35) ................ angularis Lacordaire


60 61 62 63

S 64 65 66 67

68 69 70 71
Figures 60-71. Dorsal habitus, line = 1.0 mm: 60.) Ischyrus
n. sp. 10; 61.) I. n. sp. 11; 62.) I. pictus Gorham;
63.) I. pictus var.; 64.) I. episcaphulinus Gorham;
65.) I. collatinus Crotch; 66.) I. elegantulus
Lacordaire; 67.) I. elegantulus var.; 68.) I. chacojae
Gorham; 69.) I. chacojae var.; 70.) I. scutellaris
Gorham; 71.) I. scutellaris var.

36.(34') Pronotum with 2 free rectangular spots; lacking

sutural spot near elytral apex (Fig. 64) .

............................... episcaphulinus Gorham

36'. Pronotum with 1 transverse spot; with a sutural spot

near the elytral apex (Fig. 65) ..... collatinus Crotch

37.(32') Pronotum with 2 free spots, base at most with thin

black margin, rarely with anterior spots ........... 38

37'. Pronotum variously marked with 2-4 discal spots, other

markings variously connected to margins ............ 42

38.(37) Scutellar spot narrowly connected to elytral base at

scutellum, connection narrower than the spots' width

(Figs. 66-67). ................. elegantulus Lacordaire

38'. Scutellar spot broadly connected to elytral base,

connection same width as spot ...................... 39

39.(38') Humeral and scutellar spots usually separated;

scutellar spot broadly connected to suture; antennomere

IX rounded or angled at base, not triangular ....... 40

39'. Humeral and scutellar spots connected, appearing as

one, separated from suture; antennomere IX triangular

(Fig. 24). ... .................. vespertilio Lacordaire

40.(39) Head entirely red; humeral spot not connected to

elytral base ....................................... 41

40'. Head with at least base black; humeral spot connected

to elytral base, often connected to scutellar spot

(Figs. 68-69). ....................... chacojae Gorham

41.(40) Central elytral band broken into round spots (Figs.

70-71) ............................. scutellaris Gorham

41'. Central elytral band broken into longitudinally

elongate spots (Fig. 72) .................... n. sp. 12

42.(37') Pronotum with 3 free spots ..................... 43

42'. Pronotum with 2 or 4 free spots .................... 45

43.(42) Central elytral fascia complete (Fig. 37) .

................................. tripunctatus Crotch

43'. Central elytral fascia broken into spots. ........ 44

44.(43') Lateral spot of elytra small, circular; Central

America (Figs. 38-39) ............ frontalis Lacordaire

44'. Lateral spot of elytra elongate, stripe-like; USA,

Florida (Fig. 40). ............. dunedinensis Blatchley

45.(42') Pronotum with 2 free, 2 basal, and 2 anterior spots

(Fig. 33). ........................ incertus Lacordaire

45'. Pronotum with 4 free spots; or with pronotal disc

markings based on 4 spots in a transverse line; 2

central spots occasionally connected to the anterior

margin, giving it the appearance of 2 free spots ... 46

46.(45') Pronotum with 4 free spots only; occasionally with

dark base, but no distinct basal spots ............. 47

46'. Pronotum with 4 free spots and additional markings

connected to margins ................................ 48

47.(46) Elytral central spot not connected to suture (Fig.

73) .......................... ............... n. sp. 13

47'. Elytral central band complete, one continuous marking

connected to suture, possibly reaching lateral margin

(Fig. 74) ......................... tetrasticus Gorham

(0a \

Figures 72-78. Dorsal habitus, line = 1.0 mm: 72.)
Ischyrus n. sp. 12; 73.) I. n. sp. 13; 74.) I.
tetrasticus Gorham; 75.) I. n. sp. 14; 76.) I. n. sp.
15; 77.) I. fulmineus Delkeskamp; 78.) I. n. sp. 16.

eS 5 4



48.(46') With distinct anterior pronotal markings, or

markings connecting discal spots to anterior margin 49

48'. Without distinct anterior pronotal marks, discal spots

free (Fig. 75) .............................. n. sp. 14

49.(48) Each pronotal hind angle with a spot, occasionally

reduced and appearing as dark swelling at margin of

disc ............................................... 50

49'. Pronotal hind angles without spots, lateral margin dark

but not extending onto disc (Fig. 76) ....... n. sp. 15

50.(49) Humeral spot connected to elytral base; central

elytral band divided by orange except at stria V & VI

(Fig. 77). .................... fulmineus Delkeskamp

50'. Subhumeral spot not connected to elytral base; central

elytral band completely divided by orange (Fig. 78). .

....................................... n. sp 16


Ischyrus aleator Boyle

Ischyrus aleator Boyle 1954:46-48.

Diagnosis. Unique in Ischyrus by its linear elytral

spots (from base at humerus to apical third), pronotum

lacking free spots, and weakly pinched prosternum.

Description. Length: 5.6-7.4 mm; Width: 2.5-3.4 mm.

Body elongate, parallel-sided, widest at basal third elytra;

strongly microreticulate, dull; pale orange with black

pattern (Fig. 54).

Head orange, often with black epistome. Pronotum

entirely edged in black; anterior edge with 2 spots; basal

edge with 2 spots farther apart than anterior spots; spots

occasionally touching on disc. Scutellum black. Each

elytron with black epipleural fold, often with pale base;

suture finely edged in black; disc with elongate triangular

stripe, widest anteriorly, narrowly connected at base near

humerus, reaching apical quarter of elytra. Ventral color

variable from mostly black to orange with black sclerite

edges. Legs black, femur occasionally banded with pale


Head dorsal distance between eyes = 2.3 x eye width;

ocular striae reaching antennal base; vertex and epistome

puncture size = 1 x facet, separated on vertex by 2

diameters, separated on epistome by 1 diameter. Antenna

reaching base of pronotum; antennomere III as long as next 3

antennomeres combined; antennomeres IX-XI symmetrical;

antennomere XI oval, circular to transverse (similar to Fig.


Maxillary palp terminal segment semicircular; medial

edge straight at base, angle 90; lateral side rounded,

angle obtuse; width = length. Labial palp terminal segment

triangular, extended on medial side, narrow, sides rounded,

width = 0.8 x length. Labial palp width = 0.5 x maxillary

palp width (Fig. 7m). Mentum with plate broadly triangular,

length = 0.5 x width, sides slightly convex, ridge medial

extension acutely pointed (Fig. 8i)

Pronotal disc puncture size = 1 x facet, separated by 2

to 3 diameters; lateral punctures slightly larger and

denser, separated by 1 to 2 diameters. Scutellum

pentagonal, length = 0.6 x width. Each elytron with 7

visible striae; strial puncture size = 0.5 x lateral

pronotal puncture size, becoming finer toward apex;

intervals finely punctate, obscured by strong


Prosternum not keeled, convex; anterior pinch weak, if

present (Fig. 10a-b); with (female) or without (male)

foveate punctures in front of procoxa; coxal lines nearly

straight, length = 0.5 x sternal length, lines not

surpassing coxae, length = 0.6 x basal width; prosternal

plate flat, apical width = 0.75 x basal width; base

shallowly concave.

Mesosternum basal width = 2 x mesocoxal line length;

coxal lines straight, parallel to anteriorly divergent; base

sinuate. Metasternum coxal lines meeting at middle in

straight line with a row of punctures, often weak (Fig.

15b); coxal line length variable, continuous around coxae or

reaching a maximum of 0.33 distance to posterior angle of

metasternum; line behind mesocoxa deep, groove-like; sternum

medial punctures fine, few coarse lateral punctures.

First visible abdominal sternite with coxal lines

reaching 0.25 to 0.5 distance to posterior margin; rounded

between metacoxae.

Male genitalia with median lobe weakly arched, narrowed

and apically rounded; internal sac without noticeable

sclerotized structures; flagellum long and narrow, straight

and apparently rigid at basal 0.5, length = 2 x median lobe

length (Fig. 79a); base of flagellum straight, sclerite at

base elongate claw-shaped (Fig. 79b-d) (9 northern Mexican,

1 Central American dissected).

Female genitalia with spermathecal head cone-shaped;

tail swollen and recurved onto itself at middle (Fig. 79e)

(6 northern Mexican dissected).

Stridulatory files present on occipital region of

males' heads; absent on females. Males with few or no

foveate punctures on prosternum in front of procoxae;

females with few to many punctures on prosternum in front of

e79 d 9"
d c

od c

d c

d c

a ---- -

Figures 79-83. Genitalia: 79.) Ischyrus aleator Boyle
[male, Mexico, Chihuahua; female, Mexico, Sonora];
80.) I. angularis Lacordaire [male & female, Panama];
81.) I. auriculatus Lacordaire [male, Mexico, Chiapas;
female, Mexico, Veracruz]; 82.) I. bogotae Crotch
[male, Costa Rica, Puntarenas; female, Ecuador,
Pichincha]; 83.) I. boucardi Crotch [male, Panama;
female Peru, Madre de Dios]; a.) male genitalia, line
= 0.66 mm; b.) lateral view, c.) dorsal view, and d.)
anterior view of the sclerotized muscle attachment at
anterior end of male flagellum, line = 0.22 mm; e.)
female spermatheca, line = 0.33 mm.

procoxae. There is some overlap in the numbers of visible

punctures between males and females.

Variation. Markings vary dramatically in the width on

specimens from north to south. Pronotal markings often

touch in the middle, becoming stripe-like, leaving 3 pale

circles. The width of the elytral stripe varies from 1 to 3

strial intervals. Central American specimens have banded

legs, an orange elytral epipleural fold, and black epistome.

Specimens from Northern Mexico and Arizona have entirely

black legs, black epipleural fold, and an orange epistome.

The type specimen, which appears to be slightly general, has

brown legs.

Variation in mesocoxal line, from parallel to

anteriorly divergent, did not correlate with geographic

range. Specimens from Arizona and northern Mexico have the

metacoxal line short, reaching a quarter of the distance to

the posterior angle, or continuous around the coxae.

Specimens from southern Mexico and Central America have the

metacoxal lines longer, nearly reaching a third of the

distance to the posterior angle.

The prosternal pinch is not present on the holotype.

On other specimens this pinch varies from absent to weak but


Type. The holotype (original designation) of Ischyrus

aleator Boyle label data: "/ Cave Creek, Cochise Co./

Chiricahua Mts., AZ., 7000ft, June 24, 1927/ J.A.Kusche

Collector/ Van Dyke Collection/ [red] Holotype Ischyrus

aleator Boyle/" [CASC, Type #8369, studied]. Sex male.

Specimens examined. The holotype and 44 specimens,

representing 20 collection records, were studied (see

Appendix C for specific data).

Distribution. Southeastern Arizona, Mexico, El

Salvador, and Guatemala (Fig. 84).

Etymology. aleator: Latin = dice layer, gambler. Name

alludes to the resemblence of the trifoliate tawny spot on

the pronotum to the emblem of the club suit in a deck of

cards (Boyle 1954).

Taxonomic notes. The variation in leg color, size of

elytral stripe, and development of metacoxal lines, appear

to be correlated with geographic range. Few specimens with

banded legs were studied from central Mexico and Central

America. The importance of this color variety is uncertain.

References. Boyle 1956:133,136-137,169 f.131-132;

Skelley et al. 1991:65.

Ischyrus angularis Lacordaire

Ischyrus angularis Lacordaire 1842:126
Ischyrus quinquepunctatus Gorham 1887:43-44, t.3 f.6,
new synonymy.
Diagnosis. Characterized by its elongate body,

complete central elytral band, apical elytral spots touching

margins, and 2 free and 3 basal pronotal spots.

Description. Length: 5.0-5.8 mm; Width: 2.4-2.9 mm.

Body elongate, parallel-sided, widest at basal third of



Figure 84. Ischyrus aleator Boyle [circle]
and I. angularis Lacordaire [star]
distribution map.

3 'r
"r d'

elytra; weakly microreticulate, shining; yellow-orange with

black pattern (Fig. 35).

Head entirely black, or with orange epistome and frons.

Pronotum with 2 free spots and 3 basal spots; medial basal

spot small; lateral basal spots larger, tooth-like.

Scutellum black. Each elytron with orange epipleural fold;

elongate subhumeral spot connected to base, often narrowly

connected to large scutellar spot at base; scutellar spot

broadly connected to base and suture; suture finely edged

black; central band connected to lateral margin and suture;

apical spot broadly connected to suture and apical margin;

lateral margin black from central band to apex. Venter

black, except for the orange lateral abdominal sternites and

pronotal epipleuron. Legs black, tarsi brown.

Head dorsal distance between eyes = 2.2 x eye width;

ocular striae reaching 0.8 to 1.0 distance to anterior angle

of eye; vertex puncture size = 1 x facet, separated by 1 to

2 diameters; epistome puncture size = 0.5 x facet, separated

by 1 diameter. Antenna reaching basal 0.25 of pronotum;

antennomere III as long as next 3 antennomere combined;

antennomeres X to XI asymmetrical; antennomere XI transverse

(Fig. 6e).

Maxillary palp terminal segment triangular, securiform,

basally rounded, apical angles nearly 900, length = 0.75 x

width. Labial palp terminal segment triangular, extended on

medial side, rounded basally, length = 0.66 x width. Labial

palp width = 0.75 x maxillary palp width (similar to Fig.

7b). Mentum with plate broadly triangular, length = 0.6 x

width, sides straight, ridge medial extension acutely

pointed (similar to Fig. 8d).

Pronotal puncture size = 1 x facet, separated by 1 to 2

diameters; punctures smaller and denser at extreme lateral

edge. Scutellum pentagonal, length = 0.75 x width. Each

elytron with 7 complete striae; stria VIII weak, visible on

apical half; strial puncture size = 2 x pronotal disc

punctures, gradually decreasing in size posteriorly;

intervals finely punctate.

Prosternum keeled and pinched anteriorly; with (female)

or without (male) foveate punctures in front of procoxa;

coxal lines straight, length = 0.5 x sternal length, lines

surpassing coxae, length = basal width; prosternal plate

flat, apical width = 0.6 x basal width; base shallowly


Mesosternum basal width = 2.5 x mesocoxal line length;

coxal lines straight; base sinuate, lobed medially.

Metasternum coxal lines not meeting at middle; coxal lines

extend 0.5 distance to posterior lateral angle; sternum with

medial punctures fine, few coarse lateral punctures

separated by 2 to 3 diameters.

First visible abdominal sternite with coxal lines

reaching 0.5 distance to posterior edge; rounded between

metacoxae; coarse punctures laterally, fine punctures


Male genitalia with median lobe weakly arched, apically

truncate with constriction just before tip; internal sac

with end near median lobe roughened; flagellum long and

narrow, length = 1.6 x median lobe length (Fig. 80a); base

of flagellum straight, sclerite at base claw-shaped (Fig.

80b-d) (2 dissected).

Female genitalia with spermathecal head kidney-shaped,

often with top-knot; tail swollen, weakly curved (Fig. 80e)

(3 dissected).

Presence of stridulatory files on occipital region of

head unknown (heads retracted). Females have foveate

punctures on prosternum in front of procoxae; males lack

these punctures.

Variation. One specimen with a red head, probably

general, has the same collection data as a black headed


Types. The lectotype (here designated) of Ischyrus

angularis Lacordaire label data: "/ Colombie/ Angularis

Lac./ Type/ Ex-Musaeo Mniszech/ [red] TYPE/ [pale blue]

Museum Paris ex Coll. R. Oberthiir 1952/ [red] LECTOTYPE

Ischyrus angularis Lacordaire des.P.E.Skelley 1993/" [MNHN,

studied]. Sex apparently female, abdomen missing.

The holotype (by monotypy) of Ischyrus quinquepunctatus

Gorham label data: "/ [red circle on white paper] Type/ Type

sp. figured/ Bugaba, Panama, Champion/ Ischyrus 5-punctatus

Gorham/ B.C.A., Col.,VII, Ischyrus/" [NHML, studied]. Sex

not determined.