3 



Alexander and Gallatin, and was occasionally reported in June 

 to have made a visible impression npon the crop of corn. In 

 1886, however, no reports of injuries by this pest were received, 

 although an extremely dry season throughout this region would 

 seem to have favored its multiplication. None of the "armies" of the 

 previous year came then under our observation, and the precise 

 reason for the scarcity of the species this year is unknown. 



Various apple leaf insects have interposed a serious obstacle to 

 successful nursery culture, almost completely obstructing, in some 

 localities, the business of growing young apple-trees for the mar- 

 ket. At Normal, especially, in the grounds of the Home Nursery 

 Company, the mischief worked on the susceptible varieties has 

 l^een of a very discouraging character, and has even disposed the 

 Ijroprietors to transfer their apple business to a western state. 



As a result of a short series of experiments made with kerosene 

 emulsion and with lime, I learned that no liquid or powdery ap- 

 plication could reach a sufficient number of the larvae, secluded in 

 the rolled and webbed leaves, to make it at all worth using for 

 its immediate effects; but a series of field and laboratory experi- 

 ments made in 1886 has given us the means of controlling these 

 nursery pests at slight expense, — as detailed in an article on nur- 

 sery insects in another part of this report. 



The Hessian fly (Cecidomyia destructor) was locally injurious 

 in 1885 in the counties of Fayette, Effingham, Clay, Lawrence, and 

 Alexander, a few fields being left unharvested because of it in 

 the three first mentioned. A careful canvas of the southern part 

 of the State made in May and again late in June, failed to dis- 

 cover any damage except to one field each in Effingham and Law- 

 rence counties. Its isolated occurrence in these localities gave an 

 excellent opportunity to determine by experiment and observation 

 some points of interest in its midsummer life history. The re- 

 sults of our investigations, with suggestions of preventive and 

 remedial procedure based upon them, are deemed of sufficient im- 

 portance for especial discussion in a separate article. 



The CLOVER SEED MIDGE {Cecidowyici leguminicola), first de- 

 scribed by Lintner as Cecidomyia trifolii, in 1879, (the present 

 name being afterwards substituted for the above,) was first re- 

 ported in Illinois, as far as I can learn, by W. F. Carpenter, of 

 Steward, Lee county, in 1882, in a note to the "Prairie Farmer," 

 the date of which I have not at hand; but in a recent letter Mr. 

 Carpenter informs me that he first observed the pest in Illinois in 

 1878 or 187'./. As it was first observed by Lintner in New York 

 in 1877, it is difficult to say whether this was originally an east- 

 ern or w^estern species, or whether it may not have secretly pur- 

 .'.ued a less offensive course for some years in various parts of the 

 country. In Northern Illinois it was especially injurious in 1886, 

 notice of its ravages coming to the office from the Farmers' Club 

 of Marengo, in October. 



