Control of Black Vine Weevil Larvae on Container-Grown Taxus, 1982

Abstract

Abstract In late May, one-year-old Taxus plants were planted in 6-inch plastic pots in a commercial “shrub mix” consisting of equal parts of peat, sand and composted hardwood bark. The pH of the mix was 5.8. The potted plants, which were 1-year-old liners, were kept at a container area at the Valley Laboratory and were fertilized, watered, and hand weeded as necessary. The overhead irrigation system was used about 4-5 days every week through Jul and Aug to thoroughly soak the containers each time it was used. On 28 Jun, BVW eggs in the brown stage, were scattered onto the container surface and gently scratched into the upper 0.5 inch of soil of each pot. Ten plants were used for each treatment (1 plant equalling a replication) and the test was arranged in a randomized design. On 29 Jul, when larvae were in the first and second growth stages, insecticides were applied to the soil surface of the containers. Liquid formulations were mixed with 8 oz of water (pH 6.8) and washed into each pot and granular formulations were scattered into the soil and washed in with 8 oz of water. In early Nov, 5 plants from each treatment were randomly selected for making counts of surviving larvae. All soil from each container was screened to retrieve surviving larvae.