228 
Psyche 
[December 
may also act as a nest scavenger. Since this same species 
has been shown to eat the brood of Lasius americanus 
(Park, 1932b), it may well attack the young of Formica 
ulkei. 
The last beetle to be discussed is the histerid, Hetserius 
brunneipennis. The genus Hetserius numbers some twenty- 
two species, all habitually found with ants. The ecology of 
most of the species remains unknown but brunneipennis 
has been well studied (Hamilton, 1888; Schwarz, 1890; 
Liebeck, 1891; Wickham, 1896, 1900; Wheeler, 1908, 1926). 
Wheeler assigns the genus to the symphiloid synoeketes 
(1926) and has given us our only comprehensive study of 
this species (1908) . The following observations were made 
upon the brunneipennis found with Formica ulkei , and bear 
out the general conclusions of others concerning this beetle 
with different host ants. 
May 11 : a worker ant and one histerid placed in a petri 
nest at 2:00 P.M. The histerid letisimulated for five min- 
utes and then began walking slowly ahead on the last two 
pair of legs, rubbing the anterior legs together at the same 
time. It walked in this manner for thirty minutes, cover- 
ing twelve centimeters. During this time frequent halts 
were made to clean the legs and body. The front legs were 
drawn over the pronotum and head and then pushed slowly 
through the gaping mandibles. At intervals in its slow 
progress it would stop and rear up on the extended front 
legs. At 4:15 P.M. a dead ant was added. The histerid 
promptly mounted the latter but did not molest it. The 
living worker ran over to the beetle and licked the glandu- 
lar area on the right posterior pronotal angle. While the 
host attended the beetle the latter remained motionless, not 
even withdrawing its antennge. At 4:25 the histerid was 
given a thorough licking by the ant. The latter first licked 
the beetle’s head and mouth parts and while doing so re- 
gurgitated a drop of liquid on to the beetle’s mandibles. 
After this prolonged ministration the ant rolled the beetle 
over and bit twice at the right posterior pronotal angle 
again. The ant then licked the dorsal and ventral surfaces 
of the prothorax. This licking, fondling and feeding of 
the beetle continued for twenty minutes. During this period 
