Taxus, Control of Black Vine Weevil (BVW) Adults, Wooster, Ohio, 1989

Abstract

Abstract Taxus, 2.5-3.0 m tall, growing in a hedge row at OSU-OARDC campus were used to evaluate efficacy of selected insecticides against BVW adults. The row was divided into sections consisting of 3 individual plants. Each treatment was applied to a randomly selected section and separated by an unsprayed buffer area. Sprays were applied 19 Sep under sunny skies, with 16—25 kph winds. The treatment area received 10.8 cm rainfall during the test period. A CO2 compression sprayer operating at 40 psi with a single SS8004 flat-fan Teejet nozzle was used to apply treatments. Two, 10-15 cm twigs were removed, at specified intervals, from each of the three replicate plants and placed in 1-liter fonda containers fitted with nylon organdy mesh tops along with 3 ovipositing weevils per replicate. Weevils had been collected from a taxus nursery in Lake County, Ohio, and maintained on fresh taxus foliage in the rearing facility at 21-23°C, 80% + RH, and a 16 h photoperiod. Efficacy was evaluated 3, 7, 14, 21, and 42 DAT by allowing the weevils to feed on treated foliage for 72 h. After 72 h, moribund weevils were placed on fresh, unsprayed foliage, and percent mortality was assessed 48 h later.