14 FARMERS’ BULLETIN 657. 
associated with the application of fungous diseases in the destruction 
of insects in America. 
The principal fungus to be artificially employed in destroying 
chinch bugs has come to be known as the chinch-bug fungus * and 
this is the one used by the late Dr. Snow in Kansas for artificial intro- 
duction into localities where there was an overabundance of these 
bugs. 
Drs. Roland Thaxter and S. A. Forbes devised a method of artificial 
cultivation, the latter using a basis of sterilized mixture of beef 
broth and corn meal. As this fungus has many other host insects, 
it is probably present to a greater or less degree throughout the 
country every year. There is no doubt that during wet weather 
considerable benefit may be derived from the artificial cultivation 
and application of this fungus, but its efficiency is very dependent 
upon this meteorological condition, and, as has already been shown, 
chinch bugs develop in the greatest abundance in dry seasons. It 
will thus be seen that only during unusual seasons—that is to say, 
seasons that have been dry while the chinch bugs were hatching 
from the eggs but wet afterwards—can satisfactory results be expected 
from this measure. 
The effects of this fungus have probably been overestimated, 
although there is no doubt whatever that those who have been 
most instrumental in popularizing this means of destroying chinch 
bugs were thoroughly sincere and honest in their statements. One 
very important element of deception to the ordinary farmer, when 
assuming the results of the effect of this fungus, lies in the fact that 
chinch bugs, when molting for the last time and passing from the 
last-stage larva to the adult, hide away under the sheaths of corn 
and other grain, and, casting the larval skin, make their escape, 
leaving this behind. These cast skins will occur in immense num- 
bers in such places and frequently become covered with a white 
mold. It is almost impossible for anyone except an expert to dis- 
tinguish the difference between chinch bugs that have been actually 
killed by this fnugus and the mass of cast skins covered with ordinary 
mold. The uncertainty as to the effects of this fungus is responsible 
for the fact that it has fallen largely into disuse during recent years. 
It will thus be seen that this whole matter hinges upon meteorological 
conditions which are, as has been stated, most powerful factors in 
holding the chinch bug continually in check, and it is following a 
succession of dry seasons that the pest commences to become de- 
structive. During seasons of excessive abundance of chinch bugs 
this fungus will almost invariably appear among them in the fields, 
provided that at this time there occurs a considerable period of wet 
weather. Up to the present time absolute proof has not been 
1 Sporotrichum globuliferum Speg. 
