INTRODUCTORY NOTE, 
The writings of the pioneers in the economic entomology of 
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this region have a various interest, both to entomologists and 
to farmers, at the present time. Familiarity with their published 
work is important to the young entomologist especially, both 
for what it contains and for what it does not contain. A knowl¬ 
edge of the former will often prevent a waste of time on prob¬ 
lems already correctly solved; and an acquaintance with the 
deficiencies of this earlier work will show the beginner where 
further investigation may be made most immediately productive 
and profitable. The circumstances of the time made it inevitable 
that much interesting and even permanently important matter 
should be published (not to say buried) in the columns of ephem¬ 
eral and now inaccessible journals, agricultural and other, often 
the only means of publication then open to the economic ento¬ 
mologist. Even the earlier official reports have been long out 
of print, and are not now to be had by all who need them. 
To recover this scattered literature, even for a single state, 
and to make it generally available at the present time, involves 
a great amount of tedious and largely mechanical labor, which 
the investigating entomologist cannot profitably undertake him¬ 
self, but which, in Illinois, I have been able to provide for as a 
part of the clerical work of the Illinois State Laboratory of 
i Natural History; and it is to the assistants in this Laboratory, 
: especially to Prof. C. M. Weed, now of Dartmouth College, to 
Mr. John Marten, to Miss Mary J. Snyder, and to Mr. C. A. 
Hart, that the synopsis of the writings of Dr. LeBaron here pre¬ 
sented is due. 
I have to beg the indulgence of the entomological reader for 
including in this analysis much general and popular, and some 
seemingly trivial matter. A State Entomologist serves a very 
heterogeneous public, and must bear in mind a wide variety of 
