975] 
Albert and Ritcher — Cremastocheilus armatus 
287 
readily fed on ant larvae and pupae. As many as 85 pairs (male and 
female) of adult C. armatus were collected in the outer nest galleries. 
Although they were not in copula , the females later laid fertile eggs. 
No mating was ever observed in the nest or in the laboratory. Data 
from museum collections indicate a peak of flight activity during 
April and May, the time during which mating may occur. Gravid 
females normally laid their eggs below the surface at the periphery 
of the nest. 
Host records for armatus are probably incomplete (Table 1). 
F. obscuripes is the most common host but dispersal flights may 
introduce these beetles into a wide variety of ant nests. In western 
Oregon adults were collected from Formica fusca mounds, although 
immature stages were never found there. Larvae have been collected 
and reared from rich garden soil in western Oregon (Ritcher, 1966) 
indicating that under certain circumstances the immature stages may 
not have an obligatory relationship with ants. 
Table 1. Host records for Cremastocheilus armatus 
Host 
Locality 
Collector 
Life-Stage 
Reference 
Formica 
obscuripes 
E, Wash. 
W. Wash. 
Mann 
Alpert 
adult/larvae 
adult/larvae 
Mann (1911) 
New Record 
Formica 
fusca 
W. Oregon 
Ritcher 
adult 
New Record 
Formica 
subpolita 
camponoticeps 
British 
Columbia 
Howden 
adult 
Cazier (1962) 
Formica 
integra 
tahoensis 
E. Oregon 
Ritcher 
adult/larvae 
Ritcher (1966) 
Formica 
integroides 
subnit ens 
British 
Columbia 
Ayre 
adult 
Cazier (1962) 
Larval Defense 
To examine escape behavior, larvae were removed from the ant 
nests and placed in a series of containers with one to several ants. The 
normal feeding position of the larva is a C-shaped curve with the 
head and anal area closing off the ventral region from attack. The 
