Economic Entomology 



GEORGE C. DECKER 



"\X7'HEN settlers iiioxed into the Illi- 

 ' nois country, established homesites, 

 and be^an to till the virgin soil, they 

 found that hundreds of species of insects 

 native to the area readil\' transferred 

 their affections from wild plants to culti- 

 vated crops, at times in hordes sufficient 

 to destro\- the crops completely. It was 

 inevitable that the Illinois settlers, like 

 the eastern colonists, had brought certain 

 pests along with them. The hitch-hiking 

 pests included the codling moth in apple 

 barrels, the hessian fly in straw used as 

 packing material, bedbugs in bedding, and 

 lice on the bodies of the settlers. As if 

 these were not enough, other migrants, 

 such as the Colorado potato beetle, the 

 imported cabbage butterfly, the cotton 

 leafworm, the San Jose scale, the Nor- 

 way rat, and the fleas thereon, invaded 

 the area. They were followed in later 

 years by such notorious insect pests as the 

 oriental fruit moth, the European corn 

 borer, the sweet clover weevil, the Mexi- 

 can bean beetle, and the Japanese bee- 

 tie. 



The early Illinois settlers were a hardy, 

 self-sufficient, and determined lot, gener- 

 ally not rich but for the most part thrifty 

 and aggressive. They took pride in the 

 fact that they were skilled in the agricul- 

 tural arts of their da\-. At the same time, 

 they admitted that the problem of coping 

 with the many insect pests that damaged 

 their crops, annoyed their livestock, and in- 

 vaded their homes was beyond their com- 

 prehension. They sought the aid of neigh- 

 bors, school teachers, doctors, and local 

 amateur naturalists, who in turn sought 

 the counsel and advice of Fitch, Harris, 

 and other entomologists located in the 

 far-ofif New England and Atlantic coastal 

 states. When these sources of informa- 

 tion proved inadequate, the settlers ap- 

 pealed to the state legislature to appro- 

 priate funds and to appoint a state ento- 

 mologist to study what appeared to be 

 the most perplexing of all their problems. 

 On Februarv 27, 1867, the Illinois Gen- 



eral Assembly created the office of State 

 Entomologist. 



EARLY HISTORY 



Pleasant surprises await the curious 

 who attempt to assay the extent and use- 

 fulness of man's knowledge of insects, 

 their habits, and control measures in the 

 1850's and 1860's. It is gratifying to note 

 that local, self-trained entomologists such 

 as Walsh, Le Baron, Thomas, Shimer, 

 and Riley had collected and identified 

 hundreds of species and that they possessed 

 a remarkable knowledge of the life cycle 

 and ecology of perhaps three-fourths of 

 the economic species ordinarily included in 

 any current list of noxious insects in the 

 Midwest. Le Baron (1871:5-6) sum- 

 marized the situation as he saw it at that 

 time: 



The history of many of our noxious insects, 

 and especially the most notorious of them, has 

 been pretty thoroughly traced, not only by the 

 entomologists expressly employed by several of 

 the States for this purpose, but also by many 

 other active gleaners in this field. Still, any 

 one wh© enters upon the study of this extensive 

 subject, soon finds work enough upon his 

 hands. It cannot be said that the history of any 

 insect is perfectly and absolutely known, and 

 it is a notorious fact that some of the insects 

 which have been longest known and studied, 

 such as the Plum Curculio and the Apple 

 Worm, are the very ones which are causing 

 the most damage to the horticulturist at the 

 present day; and if we take into account the 

 multitude of insects which are preying upon 

 our shade and ornamental trees and shrubs, 

 which, in the estimation of many, are scarcely 

 inferior in value to the fruit bearing trees, we 

 may safely conclude that the prospect is very 

 remote when the work of the practical ento- 

 mologist will cease or materially diminish. 

 And the force of this view is greatly enhanced 

 by the [occurrence], every year, to a greater 

 or less extent, of new species of noxious in- 

 sects, or rather of insects which, having ex- 

 isted here or elsewhere in moderate numbers, 

 from time immemorial, have suddenly sprung J 

 into destructive profusion in consequence of an I 

 abundant supply of congenial food, or the ab- 

 setic'j of their natural enemies, or other condi- 

 tions favorable to life, some of which are 

 known, and some of which are obscure or in- 



[104] 



