A BACTERIAL ENEMY OF THE CHINCH BUG. 57 
element that serves to enervate and reduce the older larvae and pupzx, 
as well as many recently developed adults among them? Is there 
nothing that, not of itself fatal, so acts upon the system of the bugs 
that they are brought into a condition of susceptibility—a sort of 
“ 9o-between,” so to speak, but which demands atmospheric moisture 
before it will rise to an aggressive state? 
A BACTERIAL ENEMY OF THE CHINCH BUG. 
Forbes finds that the bacterium Bacillus insectorum Burrill is nor- 
mal to the chinch bug and occurs always in the intestinal coeca, and 
the writer has often wondered if this were not the very reducing ele- 
ment. In a paper contributed to the “American Practitioner,” Sep- 
tember, 1891, he describes the effect of this bacteria on the cceeca as 
completely destroying the secreting epithelium, the cells of which 
break down and disappear, leaving the delicate tubes filled with a 
vast mass of microbes with some small intermixture of droplets of 
fat and a little nondescript débris, the result of cellular decomposi- 
tion. Now, it certainly seems to the writer that we may here have the 
very enervating element necessary and which, in order to become sufli- 
ciently aggressive to perform its functions perfectly, requires the 
very conditions afforded by frequent showers, without which it is 
comparatively helpless. We know very well that human beings are 
far more susceptible to disease when weakened by fatigue, dissipa- 
tion, or other forms of exhaustion, and under such conditions suc- 
cumb to disease when they would otherwise enjoy immunity there- 
from. We will not, however, follow this further, but submit it as a 
problem well worthy of careful consideration and study. In his own 
experiments with Sporotrichum globuliferum the writer has found 
that under the most favorable conditions the fungus will attack even 
the youngest larve, while Forbes states that it will also attack the 
eggs, but in the fields it seemed generally most prevalent among the 
more advanced larvee, pupe, and newly developed adults, though 
much depends upon meteorological conditions and the abundance of 
chinch bugs, as well as the time during the breeding season when 
the fungus is doing its work. That is to say, there is a time at the 
beginning of the breeding season when there are only adults and 
young larve; later there will be larve of various ages, and, toward 
the last, few if any of these, but all will be either pupe or adults. 
For some reason it seemed more difficult to get the Sporotrichum to 
work satisfactorily when the chinch bugs were beginning to breed 
than later on, the last of June and the early part of July. These 
facts are mentioned here to show that, judging by their effects, these 
fungi hold a secondary place. 
