Flowering Crab, Control of Fall Webworm, Wooster, Ohio, 1990

Abstract

Abstract Flowering crabapple trees, 2-4 m tall, growing in a research plot at the OSU/OARDC campus, were used to evaluate efficacy of selected insecticides against fall webworm larvae. Twigs having small tents were removed, 4 Sep, from Mortis in Allen Co., OH, placed in plastic bags and transported to Wooster in coolers. Tents were attached to Malus trees with a Twistee at the OARDC research plot. A KWH backpack mistblower, operating at half-throttle on aperature setting # 3 for 30 sec, was used to deliver about 600 ml of finished spray to each tree. Sprays were directed toward the web and surrounding foliage on each of 3, single-tree replicates per treatment. Sprays were applied 8 Sep when conditions were cloudy, 21°C, with 0-8 km/h winds. There were 2.5 cm of rainfall in the experimental area during the test period. Treatment effectiveness was evaluated 5 DAT by dismantling each web and assessing larval condition.