Methods of Evaluating Insecticides for Control of Plum Curculio, 1975

Three methods were used to evaluate 23 insecticides against adults of the Georgia strain of laboratory-reared plum curculios. All tests were conducted in a screened insectary during May and June under constant flourescent light with unsexed beetles 1-3 weeks old. Method I involved dipping thinning apples into aqueous preparations of insecticides that contained 0.03% Tween 20. After drying, apples were divided equally among three 16-oz cups. After 0 or 4 days, 20 beetles/cup were confined with water wicks in the cups which were covered with cheesecloth. Percentage mortalities after exposure to each residue (3 reps) were averaged for each dose of each insecticide. Method II involved immersion of adult beetles (20/cup) in aqueous preparations of insecticides containing 0.03% Tween 20. After drying, beetles were placed with several clean thinning apples in cups and covered as previously described. Percentage mortalities (3 reps) were averaged after 4 days. Method II was designed to determine effectiveness of residues of foliar sprays in the field. Individual peach trees were sprayed (3 reps); then after 0 or 4 days, branches were brought to the insectary and placed in screen cages with the stem of each branch inserted into a florist’s water vial to keep foliage fresh.