REPORT OF THE STATE ENTOMOLOGIST I918 53 



the maggots and such atmospheric conditions are also favorable to 

 activity by the midges. On the other hand, dry, warm weather 

 would tend to restrict the time when the midges can deposit eggs 

 successfully by hastening the developm.ent of the grain and par- 

 ticularly its hardening, the latter probably vitally afl'ccting the suc- 

 cessful development of the miaggots. There is a very close relation 

 between the development of the related Hessian fly and the condition 

 of the grain. Soft-stemmed varieties are frequently very seriously 

 injured while nearby stiffer-stemmed varieties are almost immiune 

 from attack. Striking variations may also be seen in different parts 

 of a field, the more succulent-stem.med grain growing on moist land 

 suffering more than the harder stalks of the same variety on gravelly 

 knolls. The spring and early summer of both 1917 and 1918 were 

 unusually cool and m.oist and the midge appears to have been excep- 

 tionalJy numerous. This at least suggests an intimate connection 

 between the welfare of the insect and climatic conditions at the time 

 the grain is develop: ng. Weather conditions can not be changed. 

 If the above is true, however, the probabilities favor decidedly less 

 injury than during the last two seasons. 



Control measures. The prolonged period during which wheat 

 midges may be in flight and the general distribution of the insect 

 throughout the grain-producing areas renders it extremely improbable 

 that practical modifications in time of sowing, in rotation of crops 

 or method of preparation, would have any very material influence 

 upon this pest. We are strongly of the opinion, however, that the 

 best possible preparation of the soil so as to promote a vigorous 

 growth is of importance in the production of a medium to fair crop 

 in spite of midge infestation. 



We therefore advise following previous methods and using the 

 same varieties, varying only in giving if possible better preparation. 

 Otherwise changes may result in even more serious losses, specially 

 if this be in the date of sowing, since an earlier seeding, as many 

 growers have learned to their cost, may result in great injury by 

 Hessian fly. 



Bibliography 



The following are some of the more important references to this 

 insect, though no attempt has been made to compile the ong list 

 of general notices regarding wheat inidge, since these can easily 

 be obtained by reference to well-known bibliographical works . 



1857 Gehin, J. B. Notes Pour Servir a L'Histoire des Insectes Nuisibles a 

 L'Agriculture dans le Department de la Moselle, no. 2, Insectes qui 

 attaquent les bles, p. 19-38 (Cecidomyia) 



