1929 ] 
Myrmecocoles of Formica ulkei 
195 
ECOLOGICAL OBSERVATIONS UPON THE MYRME- 
COCOLES OF FORMICA ULKEI EMERY, ES- 
PECIALLY LEPTINUS TESTACEUS 
MUELLER 1 
By Orlando Park, 
Whitman Laboratory, University of Chicago 
In the autumn of 1928 certain observations were made 
upon the blind beetle, Leptinus testaceus Mull, in the Chi- 
cago area , which was found associated with other species of 
Coleoptera in the nests of the mound-building ant, Formica 
ulkei Emery. Some of these data are presented at this time. 
The Ecological Status of Leptinus testaceus. 
Leng (1920) gives the general distribution of this species 
as Europe, Iowa, Ohio, Pennsylvania, District of Columbia, 
and British Columbia, and Brendel (1887) lists testaceus 
from the vicinity of Peoria, Illinois. Its presence in the Chi- 
cago area is attested to by only two previous records, e.g., 
Longley (1905) found a solitary specimen in a mouse nest 
at Clarke, Indiana, and Blatchley (1910) records the 
species from Lake County, Indiana, finding it from March 
11 to December 1, when it probably hibernates in the 
imaginal state. 
This leptinid apparently has a wide range of hosts, being 
found upon, or in the nest of, wood-mice, field-mice, moles, 
!The term “Myrmecocoles” is used here, rather than “Myrme- 
cophiles”, not as an additional burden to the terminology. The usage 
of the former is broader, embracing all of those species occurring in 
the nests of ants, and less definite, since the degree of association 
between occupant and host is not known with exactness in many 
instances, and consequently reserves for the latter term species where 
an intimate relationship is known to exist. 
