1975] 
Albert and Ritcher — Cremastocheilus armatus 
285 
Life History 
During the month of May, females laid eggs scattered throughout 
the outer soil edges of the ant nest. Here rich deposits of vegetative 
debris had accumulated and ant activity was low. Under laboratory 
conditions females laid a total of 3 to 12 eggs each. The broadly 
oval white eggs (Fig. 2) hatched after two weeks. First larval 
instars were collected until the middle of June. Second instars were 
found from June until the middle of July, and third instars were 
collected from the middle of June to the middle of August. The 
pupal stage lasted two more weeks, indicating that under field con- 
ditions development from egg to adult occurred in less than 4 months. 
Most ant nests contained fewer than 30 larvae, although several 
nests contained well over 200. Second and third instars were gre- 
garious, feeding within the vegetative debris just below the soil 
surface. Late third instars were darkened posteriorly due to the 
large number of fecal pellets retained in the abdomen. When un- 
covered, the larvae were quickly seized and bitten by many ants. 
They escaped the ants by rapidly burrowing down through the nest 
material. Late third instars left the outer soil edges and moved 
inward towards the center of the thatch mound to pupate. This 
took place during the hotter days of July when the ants were not 
very active in the upper mound area. 
In the dry twig area above the ants’ brood chamber larvae con- 
structed elliptical earthen cases within which they pupated (Fig. 3). 
Easily damaged when newly formed, several of these pupal cases 
soon dried and hardened together into a protective clump. Adults 
eclosed during the late summer days and a few could be found on 
the surface of ant mounds at this time (Fig. 4). 
As colder weather approached, the beetles moved deeper within 
the nest, often ending up a meter or more below the soil surface. 
Here the adults overwintered surrounded by dormant ants (Fig. 5). 
Periodic collections of overwintering adults revealed that within a 
few minutes at room temperature the beetles became active, even if 
temperatures outside the nest were below io° C. Females often laid 
several eggs within a few days at room temperature but none of the 
eggs laid during the winter period hatched. 
The following spring the adults moved back up to the outer areas 
in the mound. Most of the adults were collected within 3 centimeters 
of the nest surface at this time. Flight was so rapid at temperatures 
above 24 0 C. that mark and recapture methods were unsuccessful in 
determining the flight range. During this same period adult beetles 
