x 
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 appear- 
ance in extreme Northern Illinois of two roREST CATERPILLARS 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, My attention 
was especially called to them by correspondents in Freeport, Rockford, 
and Argyle, and an assistant was sent from the office to investigate the 
outbreak. The caterpillars responsible for the injury were Hdema albi- 
frons and Halesidota carya. 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 im 
the basement of the State House were found infested; cases in which 
books and documents were stored were hollowed out by these ants; and 
in many instances considerable injury 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 mEar, Morn (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 excessive abundance during both years covered by this 
report of an injurious Grass TNsEcT, Crambus camurellus, which did 
noticeable damage to lawns; aud the first report of the arrival in the 
State of the notorious HORN-FLY, which since its advent from Europe 
had been confined to eastern localities. 
The CLOVER SEED MIDGE (Cecidomyia leqguminicola), was found 
abundant in 1891 and 1892 throughout the northern half of the State, 
from Ogle county to Champaign, and it is very probably still more 
widely distributed. 
Specimens of a large FLEA-BEETLE, Disonycha pennsylvanica, sent 
me from Griggsville, in Pike county, with the information that they 
were injurious to apples, were confined under a bell jar with cut pieces 
of apple. upon which they fed very freely. They were, however, proven 
by experiment to be entirely unable to bite through the skin of unin- 
jured fruit. In the numbers in which they were found at Griggsville, 
hibernating in the apple orchard under bark, and especially under bands 
used as traps for the codling moth, they might easily do considerable 
injury by gnawing and hollowing out specked apples upon the trees. 
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