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10 Contagious Diseases of the Chinch-bug. 
CONTAGIOUS DISEASES OF THE CHINCH-BUG. 
_ To Doctor Forbes more than to any one else are we indebted 
for our knowledge of the two fungus diseases of the chinch-bug. 
He first observed the gray fungus (Empusa aphidis) in 1882, and 
in 1887 he found the white fungus (Sporotrichum globuliferum) 
infesting chinch-bugs in Illinois. To Doctor Forbes belongs 
the credit of being the first.to discriminate between the two 
diseases (Hmpusa and Sporotrichum). 
In 1888 wide-spread destruction to chinch-bugs by spontane- 
ous fungus disease was reported by Doctor Forbes in Illinois, 
by Professor Lugger in Minnesota, by Professor Gillette in 
Iowa, and by myself in Kansas. Professor Lugger was the first 
to endeavor to spread the disease by sending into different parts 
of the state packages of dead bugs. 
From 1888 to the present time, those outside of Kansas who 
have been especially active in studying the disease of the chinch- 
bug have been Professors Forbes in Illinois, Lugger in Minne- 
sota, Webster in Ohio, Osborn in Iowa, and Bruner in Nebraska. 
Professor Webster made the first careful experiments to deter- 
mine the effect on the fungus of weather conditions. Professor 
Forbes has found that the supposed bacterial disease of the 
chinch-bug, Micrococcus insectorum, is not really a disease, but 
that the presence of this bacterium in the chinch-bug, and of 
similar ones in other Hemiptera or true bugs, is a condition 
normal to the gastric pouches of these insects. 
In reviewing the recent work of these other investigators, I 
can do no better than make extracts from their published re- 
ports. 
Doctor Forbes in his last report * has added to our knowledge of 
the life-history of the chinch-bug. The experiments were made 
by an assistant, Mr. W. G. Johnson. 
‘*The rapid increase of the chinch-bug under favorable circumstances is of 
course dependent primarily on its normal breeding rate, but just what that rate 
is has not hitherto been precisely ascertained. It has been commonly asserted, 
indeed, since 1867 that the number of eggs deposited by a single female is about 
500, but this was a mere estimate based on general field observations made in 
* Nineteenth Report Entomologist of Illinois, 1896, pp. 177, 178. 
