308 
Ittinois NATURAL History SurvEY BULLETIN 
Vol. 26, Art. 3 
Fig. 17.—Damage inflicted by squirrel or squirrels to 
underlying mycelial pad of Endoconidiophora fagacearum. 
cycle of the fungus. The destructive 
feeding habits of some of these insects, 
particularly the Nitidulidae, on labora- 
tory cultures of Endoconidiophora faga- 
cearum were mentioned earlier, page 297. 
Also, the role of some insects in the de- 
struction of mats in the field was ob- 
served, fig. 164. 
During the spring three immature 
mats, which had no insects on them when 
examined, were covered with clean plastic 
covers so that no insects could reach the 
fungus; then the bark, which had been 
removed for the examination, was _ re- 
placed over the mats and nailed securely 
to the trees. Three other immature mats, 
which had several individuals of both 
Glischrochilus obtusus and Colopterus 
truncatus present, were covered in the 
same manner. 
The mats on which no insects had been 
seen remained in good condition for be- 
tween 4 and 6 weeks, after which con- 
tamination by bacteria and fungi other 
than Endoconidiophora fagacearum was 
evident. The mats with insects present 
declined rapidly, reaching a stage of com- 
plete deterioration in 2 weeks. It was 
observed that, throughout the spring and 
the bark of an oak tree and the 
summer, mats infested by large numbers 
of Nitidulidae deteriorated rapidly. Dur- 
ing the winter months, when insect activ- 
ity was low, mats lasted much longer. 
Another role in which insects may be 
important is that of spermatizing mats 
with conidia of opposite compatibility 
groups, as shown experimentally by Leach 
et al. (1952) with two species of Niti- 
dulidae and one of Orthropidae. Any of 
the species of insects listed in table 13, 
or even mites, might conceivably perform 
this role. 
At least 3 of the 40 or more species of 
insects that were found on mats were 
present during each of the winter months 
as well as in the spring and summer, table 
13. Several species were prevalent in 
October and November. During the cold 
months of January and February only 3 
species were constantly associated with 
the mats; these were adults of the order 
Collembola and Glischrochilus obtusus 
and larvae of Carpophilus sp., which were 
usually present in large numbers through- 
out the 10-month period. Although Car- 
pophilus larvae were often found embed-— 
ded in ice on the mats, many of them sur- 
vived and, on warm days, fed on the fun- 
