Evaluating Foliar Sprays for Controlling Birch Leafminers on Birch, Wayne County, Ohio, 1985

Efficacy of selected insecticides was evaluated against birch leafminer on 4- to 5-m-tall birch trees growing in an experimental plot under standard nursery management conditions at the Ohio State University Agricultural Research and Development Center near Wooster. Sprays were applied to 4 single-tree replicates/treatment using a KWH backpack mistblower operating at 0.5 throttle and aperture setting 4 delivering 950 ml of finished spray to each tree. Trees were sprayed 23 Apr under sunny skies at 18°C with no wind. Treatment effectiveness was evaluated on 8 and 22 May by counting the number of mined leaves for the first 10 leaves from the apex of 4 lateral twigs on each replicate tree.