216 
Psyche 
[December 
BEETLES ASSOCIATED WITH THE MOUND- 
BUILDING ANT, FORMICA ULKEI EMERY 
By Orlando Park 
Northwestern University 
The mound-building ant, Formica ulkei Emery, has been 
reported as far west as South Dakota to Nova Scotia and 
New Brunswick (Wheeler, 1926; Holmquist, 1928). It is 
recorded from Wisconsin (Burrill and Smith, 1918) and 
Illinois, and is apparently abundant in northern Ohio 1 where 
its range merges with that of the eastern mound-builder, 
Formica exsectoides. 
In Illinois ulkei is at present known only from the Chi- 
cago Area where it is well established in two localities 
(Palos Park and Palatine). In both places the numerous 
mounds, varying from young nests of less than a foot in 
diameter up to old hills more than four feet across, are 
found within the upland oak-ash-hickory forests, where 
they tend to follow the forest margins and clearings. 
These ant mounds present an infinite array of problems 
which remained uninvestigated until 1926. Since then, a 
literature upon these Illinois mounds has steadily accumu- 
lated, including the life history and behavior of the host 
ant (Holmquist, 1928a), hibernation (Holmquist, 1928b; 
Dreyer, 1932), distribution of the nests (Dreyer and T. 
Park, 1933), and the species of arthropods associated with 
the host ant (Park, 0., 1929; Park, T., 1929). 
Among the numerous arthropods associated with ants 
the myrmecocolous beetles are numerous, both in species 
and individuals. Many of these beetles are nest scavengers, 
X I am indebted to Dr. C. H. Kennedy for personal communication upon 
the Ohio distribution of Formica ulkei and exsectoides. The latter 
species is reported from Iowa (Wickham, 1900) and Indiana (Blatch- 
ley, 1910) so that the actual distribution of these two closely allied 
ants can not be certainly known until a carefully planned survey can 
be made. Both ulkei and exsectoides are present in the Chicago Area, 
however; a small mound was investigated, and workers preserved, 
near Smith, Indiana on August 27, 1934. These ants I sent to Dr. M. 
R. Smith who determined them as Formica exsectoides. 
