Soil application of systemic insecticides for control of woolly apple aphid (Eriosoma lanigerum (Hsm.)) in Rhodesia

Abstract

Previous attempts to control Woolly Apple Aphid (Eriosoma lanigerum (Hsm.)) in Rhodesia are briefly reviewed. By the application of dimethoate at a rate of more than 5.0 grams a.i. or of vamidothion at more than 6.0 grams a.i. to the soil in the drip area of the tree, it was found that good control of both the foliar and root populations of the insect could be obtained on three-year-old apple trees 10 feet high. and the treatment appeared to remain effective for three seasons. It is considered that the timing of the application, the soil temperature, and the amount of wead cover are all important factors in affecting the amount of insecticide taken up by the apple trees.