Birch, Evaluation of Insecticides for Control of Birch Aphid, Wayne Co., Oh, 1984

Abstract

Abstract B. pendula (4.5 m tall) and B. pubescens (3.5 m tall) growing in an experimental birch planting at The Ohio State University, Ohio Agricultural Research and Development Center near Wooster were chosen for evaluating efficacy of selected insecticides against birch aphid. A KWH backpack mistblower operating at 0.5 throttle and aperature setting 2 was used to deliver 960 ml of finished spray to each of 2 ‘pendula’ and 640 ml to 1 ‘pubescens’ for each treatment. Application was made 4 Sept under clear, evening skies at 18°C with no breeze. Treatment effectiveness was evaluated 1, 3, 7, and 14 DAT (days after treatment) by holding a collection tray beneath 2 branches per tree and striking each branch twice. Collections were placed in glass vials; aphids were counted in the laboratory with the aid of a binocular dissecting microscope. The same procedure was followed to make pre-counts on the day of application, prior to treatment, to provide baseline information on aphid population density.