OCCURRENCE, DEVELOPMENT, AND DISTRIBUTION OF CEREAL APHIDS ON EARLY AND LATE CULTIVARS OF WHEAT, BARLEY, AND OATS IN SOUTHWESTERN QUEBEC

Abstract

In southwestern Quebec, cereal aphids started to infest cereals in the first week of June, and reached their peak on the second and third weeks of July. There was a significant correlation between the number of alate aphids produced and total number of aphids per colony for R. padi and M. avenae but not for R. maidis. The percentage of alate aphids in colonies of all three species increased as cereals matured. The index of aggregation (b) showed M. avenae was distributed randomly in the field while R. padi and R. maidis were distinctly aggregated.