42 THE CHINCH BUG. 
found in the bacterial and fungoid diseases which may be artificially 
introduced when nature fails to come to our aid," an opinion at that 
time largely based upon the investigations of Professor Forbes and 
his own observations of the chinch bug in Kansas, thus paving the 
way for the experiments of 1889. Professor Snow had now obtained a 
specific determination of the fungous disease as (Empusa) Entomoph- 
thora aphidis Hoffman, although there is some ground for the suspi- 
cion that Sporotrichnim globuliferum was also present. 
Entomophthora aphidis was already known to affect hemiptera in 
Germany and the United States. Dr. Eoland Thaxter states that, as 
early as 1886, his attention had been called to the attacks of this fun- 
gus on aphides in the greenhouses at Cambridge, Mass., where it acted 
as a decided check, and later, in 1887, Dr. L. O. Howard had called his 
attention to great quantities of aphides dying with the same disease 
on clover near the Agricultural Department buildings in Washington, 
D. C* 
Field and laboratory experiments in Indiana. — On July 20, 1889, the 
writer, at that time a special agent of the Division of Entomology of 
the United States Department of Agriculture, stationed at Lafayette, 
Ind., received, through the kindness of Professor Snow, enough mate- 
rial with which to make some experiments, the chinch bug being at 
that time very abundant at Lafayette, and an exceptionally good 
opportunity thus being offered for experimentation. The results of 
these experiments were published in detail in Bulletin 22, United 
States Department of Agriculture, Division of Entomology (pp. 55-63), 
but as this was the first series of experiments carried out with a view 
of testing with exactness the precise effects of varying degrees of tem : 
perature and atmospheric moisture on the growth of the Entomoph- 
thora, and carefully following out the progress of the disease under 
varying meteorological conditions, the matter is here republished in 
full, the bulletin in which it was originally included being now out of 
print. 
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 witb young chinch bugs. The hills of corn on which the bugs had been 
placed were isolated from others, equally badly infested, by narrow frames of boards 
placed on the ground and the upper edges covered with tar. This last precaution 
was taken in order to prevent 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 Entoinophthora, and by the 30th enough 
others were found to show that the fungus had fully established itself and the bar- 
riers about the isolated hills were removed. On August 2, dead bugs covered with 
* Memoirs of the Boston Society of Natural History, Vol. IV, p. 176. 
