Biology of the Diamondback Moth, Plutella maculipennis (Curt.) (Lepidoptera: Plutellidae), in Eastern Ontario. II. Life-History, Behaviour, and Host Relationships

The diamondback moth, Plutella maculipennis (Curt.), is one of three species of Lepidoptera that annually cause serious commercial damage to cabbage and related crops in Ontario. It has long been underrated as a pest of cruciferous crops, possibly because of its small size; in eastern Ontario, it is much more numerous than the other two species and ranks second in importance to the imported cabbageworm, Pieris rapae (L.) (Harcourt et al. , 1955). Its biology in eastern Ontario was investigated from 1951 to 1956. The history, distribution, and synonomy of the insect and general descriptions of the stages were given earlier (Harcourt, 1956). This article presents the life-history, behaviour, and host relationships.