7 



timothy meadows and even in blue grass pastures, breeding as 

 rapidly there, to all appearance, as if these fields had been in 

 wheat. The oats especially were suffering everywhere, bugs of 

 all ages being equally dispersed throughout the fields*; and, later, 

 corn fields were invaded in the usual way, first from the edges, 

 and then by a general flight. In short, it was difficult to believe, 

 after a careful examination of this neighborhood, that the chinch 

 bugs would have been any more abundant if every other 

 field had been in wheat; while it seemed probable that if a mode- 

 rate amount of wheat had been sown, this would have received 

 the weight of the attack and the other crops would have been 

 correspondingly relieved. f 



KELATIONS OF THE AEEA OF WHEAT AND OTHER 

 CROPS TO CHINCH-BUG INJURY. 



The fact (now to be clearly seen in Illinois) that chinch bugs 

 will breed in winter wheat as well as in the spring varieties, and, 

 under certain circumstances, in oats and timothy scarcely, if at 

 all, less freely than in wheat, tends greatly to unsettle the ideas 

 of the entomologist and to confuse the practice of the farmer, 

 especially as we lack authentic detailed evidence on the relation 

 of w^heat and other crops to chinch-bug increase, drawn from a 

 territory large enough to warrant positive generalization. I have 

 consequently thought it highly important that an extended and 

 thorough-going study should be made of the relations of the cul- 

 ture of wheat (and indeed of oats, corn, and grass likewise) to 

 chinch-bug injury to the various crops. 



Conditions in Illinois during 1887 were as favorable to the in- 

 vestigation of this subject as it would have been possible to 

 arrange, since we had coincident every variation in chinch-bug 

 damage, from none whatever to the complete destruction of every 

 crop liable to attack, and also every variation in wheat culture. 



*The marked preference for wheat where both wheat and oate are accessible to the chinch bug 

 •waa very clearly demonstrated by an observation which I made in Washington county in 1886. In 

 a field sown partly to each crop, with no fence between, chinch bug's were thickly clustered on the 

 Btems of wheat, especiallv on the nodes, up to the very boundary line, but not one could be found 

 on the other grain. Even where the two were intermingled, the stalks of wheat among the oats 

 had been carefully sought out, while the oats plants among the wheat were as generally avoided. 



tOf espscial interest in this connection is the following letter written May 14, 1887, by Hon. J, 

 W. Robi9on, Towanda, Kansas, a former resident and large farmer of Illinois and an ex-senator of 

 this State : 



"The old chinch bui^s,— those of last year's crop that have wintered over,— are now extremely 

 numerous and destructive here; as numerous as I ever saw them in August and September in the 

 mature form. They have already entirely destroyed the wheat on thin soil and half of that on our 

 best lands. They have also destroyed at least half the oats crop, and, strange as it may appear, have 

 killed a few patches of corn and are distributed over all our corn, from a few to fifty on a hill, the 

 com being from one inch to six inches in height. They are laying a very large crop of eggs on all 

 these plants, but none have yet hatched. Our wheat is just heading out, and some heads are in blos- 

 som. This is the first time' I have known old, last year's bugs to lay very many eggs on young 

 com. Timothy and orchard grass are very dry and email, but not harmed by the bugs.'^' 



