THE BEHAVIOR OF DIPLOECITON NE VERM A NNI, 
A STAPHYLINID BEETLE 
ASSOCIATED WITH ARMY ANTS 1 
By Roger D. Akre and Richard L. Torgerson 2 
INTRODUCTION 
The genus Diploeciton of staphylinid beetles contains two known 
species, D. constriction Wasmann and D. nevermanni Reichensperger, 
both collected only with the army ant Neivamyrmex pilosus (F. 
Smith). D. constriction has been collected once in an emigration 
column at Minas Gera.es, Brazil, by J. F. Zikan and D. nevermanni 
has been collected twice in Costa Rica: by F. Nevermann from an 
emigration column at Hamburgfarm and in a nest by H. J. C. 
Schmidt at Farm La Caja (Reichensperger, 1939). The literature 
contains taxonomic descriptions and mention of the host ant, but no 
other information is available. 
Diploeciton are unusual myrmecoid staphylinids belonging to the 
Aleocharinae : Dorylomimini. They are shiny reddish-brown to dark 
brown in color while their host, N. pilosus , is shiny black; otherwise 
the beetles resemble their host. They have “pseudogasters” formed 
by the enlargement of the 6th-8th abdominal segments which mimic 
the gasters of the army ants, a three segmented petiole (army ants 
have two segments), and a filiform process of unknown function 
on the venter of the petiole (Seevers, 1965). The beetles have 
functional wings and presumably can fly. The legs of the beetles 
are clothed with scattered hairs along their entire lengths, with 
the hairs becoming longer and denser on the inner surface of the 
distal end of the tibiae of the first and second pair of legs. The 
staphylinids do not have tufts of hairs for rubbing their host as do 
some of the ecitophilous histerids (Akre, 1968). 
A previous paper concerned with the behavior of ecitophilous 
staphylinids (Akre and Rettenmeyer, 1966) covered methods used 
in studying army ants and their guests; additional methods are 
given by Rettenmeyer (1963). 
The findings reported here were conducted at the Smithsonian 
Tropical Research Institute (Barro Colorado Island) in the Canal 
Scientific Paper Number 3131. Study supported in part by Grant GB- 
5220 from the National Science Foundation. Work was conducted under 
Project 1802, insect behavior. 
Assistant Professor and Research Assistant, Washington State University, 
Department of Entomology. 
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