countrymen who have not the advantage of reading it in Enghsh, not absolutely 

 because they do not, some of them, know that language, but because they have 

 no occasion to read the English bulletins. 



I shall take these cecidomyiids in the order they occuuy in my mind, accord- 

 ing to the dates of our acquaintance with them. The first, the Hessian fly, I 

 have known for forty years. This insect is so well known in Quebec that 

 1 am not going to speak of it at length, nor even describe it as it is found in the 

 two Canadian works which were written about it as early as in 1856. I mean the 

 essays by Hind and Provancher under the pseudonym of Dupont. I purpose here 

 giving a summary of the control measures to be taken against this terrible foe of 

 our wheat crops. These measures, after Criddle. are the following: 



( 1 ) Plowing all infested stubble land between August 15th and the middle 

 of May of the following season, plowing to be not less than five inches deep ; 

 (2) burn all stubble and straw piles between the dates mentioned above; (3) 

 carefully gather up all screenings and use the same as feed, or destroy them 

 before May 15th ; (4 ) infested land unable to be treated by plowing or burning at 

 the proper time should be disked or cultivated as soon as possible and plowed 

 June 20th ; (5) sowing strips of grain about 20 feet wide between infested stubble 

 and newly planted grain to attract flies may be resorted to on occasions of severe 

 outbreak ( The strips should be planted early and plowed down about the middle 

 of June) ; (6) prepare a good seed bed and use the best of seed. \'igorous plants 

 will be more able to resist attack ; weak ones are easily killed out. 



The second ceeidomyiid with which I came into contact was Cccidoniyia 

 llrginioisis or Contarinia Virginiana Felt. In the Summer of 1915. I saw in a 

 Choke-Cherry tree an abnormal agglomeration of ill-shapen fruit in many of the 

 ordinary clusters. Lx)oking attentively at them, I thought that they resembled the 

 plum pockets found sometimes in plum trees subject to the invasion of the 

 Exoascus. They were of course smaller, being on an average twice the size of an 

 ordinary Choke-Cherry. Upon examination, I found them filled with a swarm 

 of very small red larvae. After having sent the specimens of these galls and 

 larvae, first to Dr. C. Gordon Hewitt. Dominion Entomologist, Ottawa, I learned 

 that the galls were due to the fact that the Choke-Cherry fruit had been punctured 

 and filled with eggs of the Cecidomyia Virginiensis. and later I received from 

 Dr. E. P. Felt, New York State entomologist, of Albany, the best American 

 authority on Cecidomyiidae. a letter revealing quite a host of insects inhabiting 

 those galls, such as: Arthrocnodax sf^iphila, Contarinia Virginiensis (Felt), Ceci- 

 domyia Virginiensis, Itonida Canadensis (Felt), Parallelodiplosis acernea (Felt). 

 Lestodiplosis, Dasyneura legitminicola. This second Ceeidomyiid may not be very 

 noxious, especially if we compare them with the damage caused by the Cecidomyia 

 destructor, previously mentioned, and the next one that we are going to submit 

 to our investigations, the Clover-flower midge, Dasyneura legnminicola. 



This Dasyneura was the third ceeidomyiid with which I became acquainted, 

 in 1918, in a clover-seeded orchard of Saint-Remi de Napierville. This is, as in- 



