DirrSIOX OF entomology 863. 



SESSIONAL PAPER No. 16 



In Manitoba, wherever applications of the Griddle Mixture were made, littla^ 

 damage was caused by the locusts. 



White Grubs (Lachnosterna spp.). 



An extended investigation into life-history, control, etc of these insect* is now- 

 being undertaken by the Division in co-operation with the United States Bureau of 

 Entomology. 



At several of the field stations, important studies have been made of the various 

 species of White Grubs destructive to field and garden crops. Large collections of the - 

 adults have been made from various plants in Ontario and Manitoba, and the life- 

 histories of the different species are being investigated. Mr. Norman Griddle,- off 

 Aweme, Man., was appointed a Field Officer of the Division to study particularly the- 

 Manitoba species of White Grubs. Six species were under observation at this sta- 

 tion, and much data were obtained as to their habits, food plants, etc. Mr. H. F. 

 Hudson, Field Officer at Strathroy, Ont., has found three species of common occur- 

 rence and at Vineland, Ont., Mr. W. A. Eoss has noted two species. 



As these insects require from two to four years to complete their life-cycle, the 

 investigations now under way will not be completed until 1917 or 1918. 



During 1913 many reports were received of injury by White Grubs. These were 

 chiefly from British Columbia, Manitoba, Ontario, Quebec, and in mostly all instances 

 the destruction was to potatoes. 



Miscellaneous. 



WiREwoRMs. — Those insects were reported as injurious from various part^ of 

 the Domanion. At Ottawa, in the comparative tests of Indian Corn on the Central 

 Experimental Farm, the injuries of the larva? of the Elaterid, Cryptohypnus aihrevi- 

 atus Say, were discovered. 



The Hessiax Fly {Mayetiola destructor Say.). — A few complaints of damage 

 by this insect were received from Manitoba, and a thorough study was begun of the 

 life-history in that province. It was found to be plentiful at Reston, Man. 



The Lesser Wheat-stem Maggot (Oscinis carlonaria Loew.). — This insect, which-, 

 in Manitoba ranks in importance next to the Hessian Fly in injury to spring wheat,, 

 was also fairly abundant in some districts. At Treesbank, ^fan., Mr. Griddle esti- 

 mated that the injury to spring wheat in June by this insect and the Hessian Fly. 

 averaged 5 per cent. ; in some fields the damage was as high as 15 pel" cent. 



The Pea Weevil (Brnclnis pisorum L.). — From reports received, this insect is- 

 undoubtedly on the increase again. Samples of infested seed peas have been forwarded 

 to the Division from localities in Ontario. Xo such infested seed, of course, should 

 be used, either -for food or planting, unless the same is fumigated with bisulphide 

 of carbon to kill the beetles, many of which remain in the seed during the winter. 

 If peas which have been injured by the Pea Weevil are used in spring for seed pur- 

 poses, a very much larger amount per acre will be required. It is, of course, inad- 

 visable to use injured peas for seed; such should be fed to stock. 



The Clover-seed Ghalcid (Bruchophagus fanchris Howard). — During the winter 

 of 1912-13 and that of 1913-14, seeds of Bed Clover (Trifolium pratense L.) and" 

 strains from this and Mammoth Bed, were found to be heavily infested with the- 

 larvae and pupae of the Clover-seed Chalcid. Fourteen samples of seed, each sample 

 containing 500 see<ls, were counted at random and it was found that the highest per- 

 centage of infestation was 21 per cent., and the lowest 9 per cent ;: the average peiv- 



IG— 5Gi VTTAWA. 



