RESIDUAL TOXICITY OF PESTICIDES USED FOR LEPIDOPTERAN INSECT CONTROL ON CITRUS TO APHYTIS MELINUS DEBACH (HYMENOPTERA: APHELINIDAE)

Fifteen compounds used for suppression of lepidopteran pests of citrus were applied in a commercial manner to lemon trees. Amounts of dislodgable residues, together with mortality of Aphytis melinus DeBach confined on treated foliage, were monitored for 36 days following treatment. Most materials caused high mortalities on the 1st day following treatment. Several materials had little effect on A. melinus after 7 days post-treatment. These included a formulation of Bacillus thuringiensis Berliner endotoxin, a formulation of B. thuringiensis exotoxin, cryolite, methomyl, mevinphos, naled, parathion, and trichlorfon. Carbosulfan, chlorpyrifos, esfenvalerate, fluvalinate, methomyl, and two formulations of carbaryl caused mortality for up to 30 days post-application. Mortality in the thiodicarb treatment was above 60% for the 36 days of the study. Mortality was correlated with amounts of dislodgable residue for each material tested.