1916] Entomology in the British Empire 21 



he commenced an investigation of the aphids affecting apple: 

 Aphis sorbi, A. pomi and A. avence, which are very injurious. 

 Greenhouse and mill-infesting insects are also studied at this 

 laboratory. At a laboratory at Strathroy, Ont., in the western 

 part of the province, Mr. H. F. Hudson, who is at present on 

 leave in Flanders, has investigated the chinch bug {Blissus 

 leucopterus) and commenced a study of the white grubs 

 {Lachnosterna spp.) which investigation is being continued in 

 his absence by Mr. J. R. Gareau. 



Our next Field Laboratory is situated at Treesbank in 

 southern Manitoba and here Mr. Norman Griddle, whose work 

 on locust control is well known, is investigating the bionomics 

 and control of white grubs {Lachnosterna spp.) and in this 

 connection I should mention that this investigation is comple- 

 mentary to that now being conducted by the United States 

 Bureau of Entomology, the intention being to study these 

 insects over the whole range of their distribution in North 

 America. The value of such co-operative inquiry is obvious to 

 all. In addition Mr. Griddle is investigating the insects affecting 

 cereals and the results of his studies of the Hessian fly and the 

 wheat-stem sawfiy have been recently published. 



The prairie region is also served by a laboratory at Leth- 

 bridge in southern Alberta where Mr. E. H. Strickland has been 

 devoting particular attention to a study of the various species 

 of cutworms which are seriously injurious to grain and other 

 crops periodically. For example, in 1912 Porosagrotis ortho- 

 gonia destroyed about 35,000 acres of wheat. Last year the 

 Army Gutworm {Chorizagrotis auxiliaris) was studied and con- 

 trol measures were demonstrated in the field with valuable 

 results. Mr. Strickland has also been investigating the 

 abundant nematode fauna associated with growing grain. 



The headquarters for our work in British Golumbia are at 

 Agassiz in the lower valley of the Frazer River. Mr. R. G. 

 Treherne, the officer in charge, has been investigating both 

 fruit insects and insects affecting vegetable crops. The results 

 of his study of the strawberry root weevil (Otiorynchus ovatus) 

 were published some time ago and his investigations on the 

 cabbage root maggots are now completed. In addition he 

 has made valuable observations as a base for further study, on 

 the wheat midge (Diplosis ? tritici) and the budmoth of apple 

 and other apple insects. 



