PSYCHE 
Vol. 82 September-December, 1975 No. 3-4 
NESTING BEHAVIOR OF 
LARROPSIS CPIILOPSIDIS AND L. VEGETA 
(HYMENOPTERA: SPHECIDAE: LARRINAE) 
By Darryl T. Gwynne and Howard E. Evans 1 
Department of Zoology and Entomology 
Colorado State University, Fort Collins, Colorado 80523 
In their revision of the genus Larropsis , Bohart and Bohart 
(1966) reported prey records for only two of the 25 described 
species. L. divisa (Patton) had been observed preying on immature 
camel crickets, Ceuthophilus sp., by Williams (1913), who also 
presented notes on nesting behavior; and R. M. Bohart himself 
had taken L. filicornis Rohwer with an adult camel cricket of the 
genus Ammobaenetes. A detailed study of the nesting behavior of 
Ancistromma distincta (Smith), a member of a closely related genus 
(often ranked as a subgenus of Larropsis) , was published by Evans 
(1958a). The present paper adds to the limited knowledge of 
Larropsis biology by reporting observations on the nesting behavior 
of L. chilopsidis (Cockerell and Fox) and L. vegeta (Fox). These 
two species are very similar structurally, live in sand dune habitats,, 
and exhibit virtually identical nesting behavior. 
METHODS 
Behavioral data were collected by following individual females as; 
they walked over the sand surface searching for burrows of their 
camel cricket prey. Observations were read into a Sony cassette tape 
recorder and were later copied into a field notebook. Burrows were 
excavated to determine nest dimensions and to locate cells and prey. 
Cell contents were kept in rearing tins with moist sand. 
Voucher specimens of both species of Larropsis and their prey 
and parasites have been placed in the collection of Colorado State 
University. 
2 Part of a study of the comparative behavior of solitary wasps, sup- 
ported by the National Science Foundation, grant GB 43790. 
Manuscript received by the editor December 10, 1975. 
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