57 
able that they were related to this destruction of the bugs. This 
conclusion was supported by the fact that they were more abundant 
in old bugs than in young, while the mortality referred to evidently 
also chiefly affected the older individuals. It was found easy to 
cultivate the bacterium artificially in organic infusions, but no 
opportunity offered to apply it to healthy insects. Until this exper- 
iment is made and the effects carefully studied, it must remain 
possible that the coincidence noted was merely accidental, and of no 
particular significance. : 
Another parasite discovered is similar to that well known as a 
common enemy of the house fly, and belongs to the same genus 
(Entomophthora). This attacks both old and young chinch-bugs, and 
finally embeds their bodies in a mass of mold. There is some reason 
to believe that this was the active agent in an immense destruction 
of chinch-bugs which occurred in Northern Illinois in 1865, as describ- 
ed by Dr. Shimer, of Mt. Carroll. Evidence is adduced of the possi- 
bility of artificially cultivating this parasite also, and applying it to 
the destruction of insects. 
TOPICAL APPLICATIONS. 
Topical applications for the destruction of insects are often of the 
highest use to the horticulturist, whose crops are much more valu- 
able per acre than those of the farmer, and both require and repay 
he more careful and continuous personal supervision and manual 
abor. 
In agriculture, however, such measures haye necessarily been of 
littie service, especially where farms are large and the work is done 
principally by machinery. To attempt to destroy the chinch-bugs 
of any considerable territory by the direct application of even the 
cheapest substances, would involve an amount of additional labor 
which could not be had all at once in the country, no matter how 
profitable its employment might be. ‘he small farmer has, however, 
a certain very decided advantage in fighting insects, over one who 
cultivates the soil on a large scale; and to him a substance which, 
at small cost, shall destroy the bugs in his wheat and corn, may 
make the difference between a, total loss of his income for the year 
and the preservation of his crops at the expense of a little additional 
labor and outlay. The manner in which the chinch-bug most com- 
monly invades the corn-field, entering it on foot from one side while 
yet unable to fly, and attacking first the outer rows, affords about 
the only opportunity to resist its assault upon the corn. Here its 
advance has often been checked by boards set on edge and daubed 
with coal tar, or by plowing and harrowing frequently a strip along 
the field, which the bugs find it difficult to cross. Here, also, topical 
applications may be used with fair prospects of usefulness. If at- 
tacket while congregated in a comparatively small space, and before 
they have spyead throughout the field (as they will usually do as 
soon as they have acquired the power of flight) the bugs may be 
exterminated before they have had an opportunity to do very seri- 
ous damage, provided that some inexpensive substance of easy 
application may be found to destroy them, 
