Adult strawberry root weevil,Otiorhynchus ovatus(L.), emerged from western Oregon soil from late May to mid-June and was present in peppermint until late July. Adult activity on plants was greatest 1–7 h after sunset and adults marked with fluorescent powder dispersed<2 m. Adults collected in the field and reared in the laboratory oviposited for 12 wk, but the percentage of fertile eggs declined significantly after 6 wk. In 1973, 68.2% of the eggs were fertile, 60.7% hatched, and 31.7% were infertile (n=760), and in 1974, 82.0% were fertile, 72.8% hatched, and 18% were infertile (n=239). Eggs hatched in 13.9±1.5 days at constant 20°C and in 12.9±0.9 days at 24°C day and 15°C night temperatures in the laboratory. Larvae were in the soil from early June until May of the following year, and pupation occurred from mid-Apr. until early June.