46 
The first clearly recognizable cases of fungous disease among 
these chinch bugs were found by me in a corn field near Shattuc, 
Clinton county, July 7, 1887, but as the fungus affecting these 
insects was not an Empusa, but belonged to a genus (Botrytis) 
but very rarely parasitic, no especial attention was paid to it at 
the time. The same fungous affection was next noticed August 
7, 1888, at Flora, Illinois. September 13, the Empusa of 1882 was 
collected in Marion county; and September 14, the bacterial form 
discovered in 1882 was observed in immense numbers in the in¬ 
testines of chinch bugs obtained at Odin. 
With this inspiring evidence that at least three kinds of disease 
were at work on the chinch bugs of Southern Illinois, active 
measures were taken at once for the fullest possible study of them 
from every point of view, entomological, bacterial, and economic. 
Without attempting at this time a full account of our work 
(still in progress), I give a few items bearing especially on the 
distribution and activity of these diseases in the State. 
The field at Odin where the bacterial disease was first detected, 
contained only a very moderate number of chinch bugs for the 
time and circumstances, and these very unequally distributed. 
The number of adults, especially, was relatively very small. 
The bugs had also a feeble vitality, as shown by the rapid¬ 
ity with which they died in transit, although put up with special 
care. Many pupae were very sluggish, moving slowly along as if 
stiff and feeble, the abdomens noticeably distended and unusually 
greenish beneath. 
Crushing both dead and living examples, and slightly diluting 
the fluids with distilled water, immense numbers of bacteria were 
apparent, moving without flagellar action, unmistakably the same 
as those studied in 1882. 
Collected in a film on a cover glass, dried, flamed, stained with 
aniline and mounted in balsam, these bacteria had the appearance 
of a short-jointed bacillus, with a pale center which did not take 
the stain. If the fluids were not much pressed or agitated, there 
were usually visible many globular masses of these bacilli, look¬ 
ing like free nuclei, but readily broken up by repeated pressure, 
the separate individuals swarming everywhere. Sometimes careful 
crushing in water would enable one to trace the streams of escap¬ 
ing bacteria to a portion of the alimentary canal protruding 
through a break in the crust. 
On the 18th of September, I killed carefully and at once dis¬ 
sected a pupa from Odin, presenting the symptoms of disease. 
First crushing on the slide portions of the fatty bodies, I recog¬ 
nized a small number of the usual bacilli, but when I isolated 
portions of the gastric cceca*, transferred to a clean slide, and 
*The chinch bug has, besides the slender Malpighian tubules, five large cceca arising some dis¬ 
tance anterior to these, which remind one of the so-called hepatic cceca of the cockroach. 
