The Development of Neodiprion swainei Middleton (Hymenoptera: Diprionidae) in the Province of Quebec

Abstract

AbstractThe seasonal development of N. swainei was recorded in northwestern Quebec for six consecutive years from 1956 to 1961. Larvae normally spun cocoons during September when temperatures were usually below the optimum for survival. An earlier and more favourable spinning period depended principally upon an early adult emergence which, in turn, was governed by prevailing temperatures, the degree of shading of the humus, the presence of encapsulated tachinid parasites, the prior period spent in prolonged diapause, and the geographic origin of the specimens. It was concluded that early emergence of adults followed by rapid development of the immature stages for successive years are prerequisites for epidemics of N. swainei in northwestern Quebec, and are unlikely in very dense jackpine stands.