BIONOMICS OF STRAWBERRY ROOT WEEVIL ADULTS, OTIORHYNCHUS OVATUS (L.)(COLEOPTERA: CURCULIONIDAE), ON YOUNG ORNAMENTAL CONIFER TREES IN SOUTHERN ONTARIO

Abstract

AbstractField and laboratory studies were undertaken in southern Ontario to gain bionomical information on the adult strawberry root weevil (Otiorhynchus ovatus), a pest of ornamental conifer trees in nurseries. Emergence of overwintering adults began on 3 June 1991 and lasted 56 days, with 50% emerging within 18 days. Adults dispersed less than 5 m in 48 days from a single release point. About 50% of females were fecund. The laboratory temperatures at which adults were reared (15, 20, and 25°C) had no significant effect on fecundity (62.3 eggs per female) but influenced longevity; adults at 15°C lived longer than at 20 or 25°C. The mean preovipositional and ovipositional periods were 31.5 and 49.0 days, respectively. Less than 1% of adult weevils released in the field survived the winter; overwintering adults lived 10 months. Egg eclosion occurred 16 days after oviposition with 78% of the eggs viable. The significance of these biological observations in the development of management strategies for this pest is discussed.