Control of Black Vine Weevil Larvae (BVW) with Soil Insecticides in Connecticut, 1984

Abstract

Abstract Two methods of application were used to test the efficacy of soil insecticides in 2 growing media common to local nurseries. The tests were carried out on a Merrimac fine, sandy loam field at the Valley Laboratory (pH 5.4) and a 1:1:1 peat, composted hardwood bark, and sand “shrub mix” (pH 5.6) in 2-gaI plastic containers. The 2 test media were planted to Taxus in 1982. Both areas were maintained using standard cultural practices with the containers being kept under overhead irrigation. From 6 Jun, when the insecticides were applied, through 6 Aug container grown plants received 1-2 h of water per day while the sandy loam plots which were not irrigated received a total of 13.5 cm of rain occurring on 14 different days. In the “shrub mix” test each treatment was a single container and in the sandy loam each treatment was a single container, and in the sandy loam each treatment consisted of 4 plants in a 0.6-m by 1.35-m plot. Both tests were randomized and replicated 4 times. Insecticides were applied 2 ways: spread over the soil surface or incorporated into the upper 2 cm of soil by hand cultivation. Liquids were poured into containers in 100 ml of water and to field plots in 312 ml (400 gal/acre), with a small watering can. Granules were mixed with 230 g of sand and were applied with a shaker bottle to each field plot, and in the container test the granules were spread undiluted on the soil. Both tests areas received 1.5 cm of irrigation 1 h after treatment. Approximately 400 ml of soil was collected on 7 Jun and 6 Aug from each container and field plot and immediately placed in plastic bags and frozen.