THE WHEAT MIDGE. 95 



season have a marked effect upon the increase of the wheat midge. 

 The year, perhaps, of its greatest ravages, on this continent, 1854, 

 was one of unparalleled drought, and it has been observed that 

 numerous species of insects appear in incredible numbers during 

 dry and hot summers. d) The palmer worm which committed 

 such ravages in the orchards during the summer of 1853, was 

 preceded by remarkably dry and hot weather. The chinch bug 

 in 1839 became excessively numerous in Virginia and the Caro- 

 linas, and was preceded by a very dry spring. In 1850 this in- 

 sect was abundant in Illinois, but during the two following years 

 it was little noticed, " but the three dry summers which have 

 now occurred have increased it prodigiously." (2) Numerous other 

 examples might be quoted to show that hot and dry weather 

 favours in a remarkable degree the excessive multiplication of 

 insects. The green plant louse was excessively common in gar- 

 dens near Toronto in 1856, during the dry early summer months 

 (129.) 



On the Remedial Measures which have been adopted 



and suggested with a view to lessen the 



Ravages of the Wheat Midge. 



161, The remarks under this heading made in the chapter on 

 the Hessian fly may be here repeated ; we can employ remedial 

 measures to check the destructive increase and devastations of 

 this insect, but we cannot provide a remedy against its general 

 appearance from time to time, under favourable conditions. 



The following plans have been adopted in the United States, 

 and also recommended frequently in Canada. The general re- 

 sult is, as before, attached in a few brief words : — 



1 . Smoking the flies lohen in the act of depositing their eggs 



(1) Por various instances of the concurrence of hot and dry weather with the 

 sudden appearance of insects of different kinds, see Dr. Fitch's Reports. 



(2) Ibid. 



