PSYCHE 
Vol. L Sept.-Dec., 1943 Nos. 3-4 
BIONOMICS OF ECTOPSOCUS PUMILIS (BANKS) 
(CORRODENTIA, C^CILIID^E) 1 
By Kathryn M. Sommerman 2 
University of Illinois, Urbana, 111. 
Two species of Ectopsocus have been recorded from the 
United States: E. pumilis (Banks) and E. calif ornicus (Banks). 
The former has been found commonly on corn (maize). Al- 
though E. calif ornicus has been taken from the palm Areca 
lutescens in the greenhouses of the University of Illinois, and 
has been reared for several generations in the laboratory on corn 
sheaths, it has not been found in the cornfields. 
E. pumilis has been recorded previously from New York, Vir- 
ginia, North Carolina, Georgia, Florida, Louisiana, Tennessee, 
Kentucky, and Missouri, where it occurs almost throughout the 
year, but most commonly in September and October. During 
this work it has been taken in Missouri, Tennessee, Illinois, 
North Carolina, Florida and Connecticut. It is interesting to 
note that these records are limited to the eastern states. 
Complete descriptions of the adults may be found in the works 
of Banks (2), Chapman (3) and further notes are given by 
Ball (1). The males (Figs. 12, 15) can be readily distinguished 
from the females (Fig. 7) by the elaborate, darkly-pigmented 
genitalia that are apparent on the dorsal side of the abdomen. 
1 Contribution No. 230 from the Entomological Laboratories of the University 
of Illinois. This paper was included as a part of a thesis submitted in partial 
fulfillment of the requirements for the Degree of Master of Science in En- 
tomology in the Graduate School of the University of Illinois, 1941. 
2 1 wish to express my appreciation of the suggestions made by Professors 
C. L. Metcalf and W. V. Balduf during this work. Thanks are also due Dr. 
A. B. Gurney of the U. S. Bureau of Entomology and Plant Quarantine for 
determination of the species concerned. 
