SMITHSONIAN INSTITUTION

MUSEUM OF NATURAL HISTORY For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 65 cents (paper cover) UNITED STATES NATIONAL MUSEUM BULLETIN 279

Larval of the Troginae in North America with Notes on Biologies and Life Histories (Coleoptera: )

CHARLES W. BAKER

Department of Biological Sciences

Boise State College

SMITHSONIAN INSTITUTION PRESS WASHINGTON, D.C. 1968 PUBLICATIONS OF THE UNITED STATES NATIONAL MUSEUM

The scientific publications of the United States National Museum include two series, Proceedings of the United States National Museum and United States National Museum Bulletin. In these series are published original articles and monographs dealing with the collections and work of the Museum and setting forth newly acquired facts in the fields of anthropology, biology, geology, history, and technology. Copies of each publication are distributed to libraries and scientific organizations and to specialists and others interested in the various subjects. The Proceedings, begun in 1878, are intended for the publication, in separate form, of shorter papers. These are gathered in volumes, octavo in size, with the publication date of each paper recorded in the table of contents of the volume.

In the Bulletin series, the first of which was issued in 1875, appear longer, separate publications consisting of monographs (occasionally in several parts) and volumes in which are collected works on related subjects. Bulletins are either octavo or quarto in size, depending on the needs of the presentation. Since 1902, papers relating to the botanical collections of the Museum have been published in the Bulletin series under the heading Contributions from the United States National Herbarium.

This work forms number 279 of the Bulletin series.

Frank A. Taylor Director, United States National Museum

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON : 1968 Contents

Page

Introduction 1 Acknowledgments 3 Literature Review 4 Systematics 6 Methods and Materials 9 Collection of Specimens 9 Preservation of Specimens 10 Rearing of Immature Stages 11 Preparation and Study of Specimens 12 Terminology 13 Illustrations 14 General Biology 14 General Description of Immature Stages 16 Life History 17 Keys to the Known Third (Final Stage Larvae) 19 Key to the Genera 19

Key to the Known Third Stage Larvae of 7 ro.v 19 Key to the Known Third Stage Laivae of 21 Generic Description of Larvae 21 Species Descriptions of Trox Larvae 25 Generic Description of Omorgus Larvae 39 Species Descriptions of Omorgus Larvae 42 Summary 53 Literature Cited 55 Appendix. Symbols Used on Figures 59 Illustrations 61 V

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Larval Taxonomy of the Troginae in North America With Notes on Biologies and Life Histories (Goleoptera: Scarabaeidae)

By Charles W. Baker ^

Introduction

The subfamily Troginae of the Scarabaeidae is represented by three genera in North America: Trox^ Omorgus^ and Glaresis, of which

Omorgus is restored to generic status in this study. Only those species of Trox and Omorgus which occur in North America are treated in this bulletin. No attempt has been made to separate the species out- side of North America into Trox s. st. and Omorgus. The subfamily contains one other , Cryptogenius, which is restricted to South America.

The genus Glaresis is known from eight species in North America. During this study numerous adults were collected in Oregon, but all attempts to rear the larvae were unsuccessful. The biology of this

genus is unknown, and the placement of Glaresis within the Troginae has been questioned by Crowson (1955). The adults and larvae of Trox and Omorgus can be characterized as facultative