REPORT OF THE SOCIETY 101 



INSECT PESTS OF CEREAL CROPS OF QUEBEC 

 W. Lochhead, Macdonald College. 



The Province of Quebec does not suffer to the same extent as some 

 of the other provinces from the attacks of cereal insect pests. The reason 

 is possibly the practical absence of fall wheat and the relatively small 

 acreage of spring wheat in Quebec, for it is well known that wheat crops are 

 the chief sufferers from attacks of Hessian Fly, Wheat Midge, Wheat-stem 

 Maggot, Joint Worm and Frit Fly. 



From records we learn that the Hessian Fly was destructive in 1805, 

 1816, 1846-1857, 1877-1884, 1899-1902, and 1913-1915; and that the Wheat 

 Midge was destructive in West Vermont and presumably also in Quebec, 

 in 1820, 1828-1836, 1852-1855-56. It was probably the destructive agent 

 about 1878, but it should be borne in mind that as a rule farmers are not 

 good reporters in cases of minute insects like the Wheat Midge, Hessian 

 Fly and others of a similar nature. They are liable to guess at the cause of 

 the injury. 



Dr. Fitch, Entomologist of New York State, called attention about 

 1854 to the relation existing between weather conditions and insect pests. 

 He pointed out that insect scourges occurred during hot dry seasons. Later 

 observations go to show that sometimes this correlation does occur, but the 

 principle does not seem to apply to all kinds of pests. Army Worm visita- 

 tion is generally preceded by one or two dry seasons; chinch bugs in the 

 Central States appear in destructive numbers after dry hot seasons; and, 

 as Dr. Fitch observes, the worst year of the Wheat Midge, 1854, was one 

 of unparalleled drought. 



Dr. Forbes, of Illinois, says that "a wet season — if not too wet — is 

 a favorable one, and a dry season an unfavorable one," inasmuch as the con- 

 dition tends to the increase in growth and food-supply to the plant. Most 

 serious insect injuries to growing crops diminish with wet weather and in- 

 crease with dry. In very wet weather "the sap of the plant may become 

 so dilute, through excessive absorption of water by the roots that it loses 

 its nutritive value, and insects dependent on it are not so well nourished as 

 by the denser sap of a plant growing in a drier soil. They consequently 

 grow less thrifty and multiply less abundantly, and may even diminish 

 rapidly in numbers during a wet season, while if the weather were dry 

 and their food nourishing they would increase steadily at a geometrical 

 ratio. After a year or two or three of drouth the intelligent farmer will be 



