It has not been known until a comparatively recent date,that chinch bugs were subject to disease. In 1867 Dr. Shimer of Mt. Carroll, Ill. , presented a paper before the Academy of Natural Science of Philadelphia, in which he gave an account of a disease which so completely destroyed the chinch bugs in the vicinity of his home that it was impossible for him to find any specimens for his collection the following year. It was not then known and, unless specimens of the diseased bugs have been preserved, it probably never can be known with certainty what that disease was. Dr. Shimer only knew that it was an epidemic disease and that when the "bugs died they were soon covered with a fungus or mould, which he thought to be the same as that which usually attacks dead animal matter. Sixteen years later Prof. Forbes, in his first report as State Entomologist of Illinois, gave a very full and interesting account of his careful studies of a bacterial disease, Micrococcus insectorum, which was very destructive to the bugs in Illinois in the summer of ’83. This was a true contagious disease and is conducted from bug to bug "by microscopic germs as small-pox or yellow fever are conducted from man to man. Such diseases when occurring in the insect world are vastly more destructive than when occurring among human kind, as the bugs neither know the danger nor have any means of averting it. Bugs killed by this disease turn dark in color, become more or less shriveled in appearance, and when dead are not usually covered with mould.
Gillette, C. P.
"Chinch bug diseases,"
Bulletin: Vol. 1
, Article 3.
Available at: https://lib.dr.iastate.edu/bulletin/vol1/iss3/3