Birch, Evaluation of Soil-Applied Systemic Insecticides for Control of Fall Webworm Caterpillars and Japanese Beetle Adults, Wayne Co., Oh, 1984

Abstract

Abstract Trees (6.4-8.9 cm dbh) growing in an experimental birch planting and infested with at least 1 webworm nest were chosen for evaluating soil-applied Standak and Di-Syston for control of fall webworm and Japanese beetles. Soil from the base of each tree to its dripline was cultivated prior to and following application of insecticides. Standak treatments were applied with a sprinkling can at the rate of ca. 545 ml of water/m2 of soil surface. Di-Syston granules were applied in salt shaker fashion to the treatment area, raked-in, and then watered as above. All treatments were applied to 4 single-tree replicates on 31 Jul, 5 days after a 3 cm rainfall, so soil moisture was adequate for movement and uptake of systemic insecticides. During the first and second weeks after application, 4.75 and 3.4 cm of rain fell, respectively, on the experimental area. There was no rain during the third week. Treatment effects were evaluated weekly by observing webs for presence of living fall webworm larvae and for evidence of web expansion. A terminal lateral twig was removed from each treated tree and placed in a 1 liter fonda cup with 5 Japanese beetle adults in the laboratory at weekly intervals for 3 wk after application. Living and dead beetles were counted 48 h after caging.