4 
X 
ment Station m February, 1892,* accompanied by a brief pro¬ 
gram of general defence. In the northern part of the State, the 
presence of insect diseases, especially of the one known as the 
‘‘white fungus’' of the chinch bug, was repeatedly noticed by us 
in the fall of 1891 and the spring of 1892, but only where local 
rains gave it an opportunity for development. In Southern Illi¬ 
nois, however, nothing of the kind was found. Singularlv in 
accord with these observations, the chinch bug in Northern Illi¬ 
nois multiplied less rapidly in 1892 than in the southern parti 
of the State, but from both sections numerous calls came to 
the office for assistance and advice, usually in the form of re¬ 
quests for infected material with which to start “the chinch bug 
disease.” Although convinced by my previous observations of 
these diseases and by laboratory and field experiments, con¬ 
ducted by us but not yet reported, that there was under the 
circumstances existing, very little probability of a valuable out¬ 
come to these experiments, I did what I could to supplv the 
spontaneous demand by making artificial cultures and sending 
out both spores and infected insects. Every such sending was, 
however, accompanied with a warning intended to prevent the 
recipient from taking the experiment too seriously, believing, as 
I did, that harm was likely to result from a dependence upon 
this still problematical method to the neglect of older and more 
laborious and costly precautions. 
Another extraordinary occurrence in a minor field was the 
appearance in extreme Northern Illinois of two forest cater¬ 
pillars almost unknown to the economic entomology of the 
State, which occurred in the summer and fall of 1892 upon the 
oak and hickory in such numbers as to completely defoliate 
these trees over large areas. Mv attention was especially called 
to them by correspondents in Freeport, Rockford, and Argyle, 
and an assistant was sent from the office to investigate the out¬ 
break. The caterpillars responsible for the injury were Edema 
albifrons and Halesidota caryse. The same injury, due to the 
same insects, spread widely northward into Wisconsin, but was 
not heard of by us south of the latitude of Chicago. 
An interesting investigation of injuries to books and papers 
by white ants was made in the winter and spring of 1892, in 
response to a request from the State Department at Springfield. 
Several rooms in the basement of the State House were found 
infested; cases in w ich books and documents were stored were 
hollowed out by these ants; and in many instances considerable 
injurv had been done to the contents of the cases. 
Matters of minor interest and importance were the appearance 
of small outbreaks of the army worm in Central Illinois; the 
occurrence of the meal moth (Pyralis farinalis) in potatoes; 
the extraordinary abundance in Cook county, for two or three 
years, of the cecropia moth, the larva of which does some 
damage in nurseries by defoliating young apple trees; the ex- 
The Chinch Bug in Illinois, 1831-1892. Bull. Agr. Exper. Station No. 19 (Feb., 1892), p. 4t 
