60 



That dry weather during spring and early summer is almost invaria- 

 bly associated with an increase, and wet weather during the same 

 period with a decrease of Chinch Bugs is usually true, but why this is 

 so has never been definitely explained. 



The fungoid disease known as Entomophthora has, since it was studied 

 by Dr. Shimer, been known to be much more fatal in wet than in dry 

 weather. How far this would prove true, and to what extent the 

 farmer could rely upon this fungus to keep the Chinch Bug in check, 

 gave the incentive for carrying out the following experiments. 



Early in July, 18S8, a large number of Chinch Bugs, principally pupa? 

 nearing the last molt, were placed in a close glass vessel and kept in a 

 very damp atmosphere and under high temperature. Although kept 

 for two weeks under these conditions we failed to produce the Entomoph- 

 thora among'them. This was accepted as evidence that the fungus did 

 not exist in any stage of development here at La Fayette, Ind., although 

 it was reported from an adjoining State. 



On July 20, of the present year, we received some dead chinch bugs 

 from Prof. F. H. Snow, of Lawrence, Kans., which were said to be af- 

 fected by jEntomophihora. These diseased bugs were placed under glass 

 with living ones from the fields, the latter being provided with food and 

 kept thus confined for fifty-three hours, when the major portion of them 

 were placed on several hills of corn, seriously infested by bugs, the 

 remainder with the dried remains received from Professor Snow being 

 scattered about over a small area of young wheat sown for experiment, 

 and also swarming with young Chinch Bugs. The hills of corn on which 

 the bugs had been placed were isolated from others, equally badly in- 

 fested, by narrow frames of boards placed on the ground, and the upper 

 edges covered with tar. This last precaution was taken in order to pre- 

 vent communication with other hills, intended as checks on those used 

 directly in the experiment. The area of young wheat over which infested 

 bugs had been placed was not inclosed, but its limits carefully marked. 

 Five days after, July 27, a single bug was found on one of the isolated 

 hills of corn which had very evidently died from the effects of Entomojrfi- 

 thora, and by the 30th enough others were found to show that the fungus 

 had fully established itself, and the barriers about the isolated hills were 

 removed. On August 2, dead bugs covered with EntomopJitJiora were 

 found in considerable numbers about hills of corn, 25 feet from where the 

 original colonies had been placed, and also throughout and even 55 feet 

 beyond the area of young wheat over which dead and affected bugs 

 had been distributed. Daily observations were now made, but the pro- 

 gress of the disease seemed to come to a stand-still. From the 5th of 

 August up to the 9th it was almost impossible to get sufficient material, 

 outside, to enable me to carry on laboratory experiments. August 13, 

 the spread of UntomophtJwra appeared to have taken on new life, aud dis- 

 eased bugs were becoming much more numerous. August 15, found 

 diseased bugs 172 "feet from any place where they had been previously 

 observed. August 20, diseased bugs' were very abundant over all of 



