INTRODUCTORY. 
For the past ten years the economic entomology of the corn 
plant has been made a leading subject of investigation in this 
State by the official entomologist, and in the course of these 
original studies a large mass of published matter has been scanned 
and summarized. The present report has been prepared in the 
hope (1) of finally bringing to bear on the practice of the corn 
farmer in Illinois all the entomological matter that ought to 
affect his procedure, and (2) of so massing and condensing the 
data from which practical and theoretical conclusions are to be 
drawn as to make it unnecessary for the investigating entomol¬ 
ogist to cover the same ground again. 
To the first end I have prepared descriptions and classifica¬ 
tions of insect injuries to corn which I venture to hope will be 
found intelligible and practically useful to the actual tiller of the 
soil as well as to the economic entomologist; and secondly, I 
have incorporated with this, for the especial benefit of the ento¬ 
mologist, more detailed and thoroughgoing discussions of the 
insects themselves and of their life histories, habits, and injuries, 
together with descriptions of the species in all stages as yet 
recognized. This report is thus written from both the agricul¬ 
tural and the entomological standpoints. 
The corn insects now recognized as in some way and to some 
extent injurious to some part of the plant number 214 species, 
of which 18 are known to infest the seed, 27 the root and the 
subterranean part of the stalk, 76 the stalk above ground, 118 
the leaf, 19 the blossom,—that is the tassel and the silk,—42 the 
ear in the field, 2 the stacked fodder, and 24 the corn in store, 
either whole or ground. The greater part of this long list, which 
is doubtless by no means really complete, is composed of those 
whose injuries are now so slight or rare as to constitute a pos¬ 
sible menace rather than to cause a serious loss; but the history 
of economic entomology, and even of the entomology of this one 
plant, teaches us that we can rarely tell in advance what to ex¬ 
pect of any possibly injurious species. In fact, some of the in¬ 
sect enemies of corn now most destructive were not many years 
ago almost unknown even to the entomologist—the northern 
corn root worm and the corn root aphis, for example. 
The principal insect species infesting this plant are the seed- 
corn maggot and the wireworms, attacking the seed ; these latter 
