590.5 ^ Jl oj f^MA^^ v 70 FIELDIANA ^1 Zoology 3 Published by Field Museum of Natural History Volume 70, No. 3 December 3 1 , 1976 The Larval Characters of Featherwing and Limulodid Beetles and their Family Relationships in the Staphylinoidea (Coleoptera: Ptiliidae and Limulodidae) 1 Henry S. Dybas Curator, Insects Field Museum of Natural History ABSTRACT The family Ptiliidae, which contains the smallest known beetles, is defined and distinguished from related families in the Staphylinoidea on the basis of the larval characters of the following eight genera from the United States and Panama, which are described and illustrated: Nossidium, Pteryx, Actidium, Nanosella, Throscop-tilium, Actinopteryx, Acrotrichis, and Nephanes. These genera represent several diverse elements in the family and include specialized forms like Acrotrichis and Nephanes, as well as Nossidium, the most generalized genus in the family. The larval characters of the closely related Limulodidae, a family composed of obligate ant associates in the New World and the Australian region, were previously based solely upon a supposed larva of Cephaloplectus from Costa Rica. This larva is considered to be wrongly associated and to belong instead to the Staphylinidae (probably Aleocharinae). However a larva of Limulodes from Illinois is described and illustrated, making it possible to characterize the Limulodidae in a preliminary way on the basis of the larval characters of a generalized genus, and to compare the larval characters with those of the Ptiliidae and other related families. The two families belong to the Staphylinoidea, a superfamily that contains about 10 generally recognized families, including the diverse and huge family Staphylinidae of more than 30,000 species. Within this superfamily, the two families share a presumably unique and derived feature the fringed galea of the maxilla with the Leptinidae, Leiodidae, and the Hydraenidae. The family Hydraenidae is often considered to belong to the superfamily Hydrophiloidea, but the larvae have a number of staphylinoid features (as noted by previous workers) and in Hydraena (but not in Ochthebius and Meropathus) possess a fringed galea which clearly relates them to the Ptiliidae and allied families in the Staphylinoidea. This 'This paper is dedicated to the memory of Professor Alfred E. Emerson. Library of Congress Catalog Card No.: 76-39773 US ISSN 0015-0754 mm. wm wm Publication 1247 29 ' l M nlSmf MAR1 1977 LIBRARY MAR 8 m UMMRT
BioStor
