Residual toxicity of selected insecticides sprayed against Asian citrus psyllid to its parasitoid Tamarixia radiata from a citrus orchard

Tamarixia radiata is the primary parasitoid of the Asian citrus psyllid (ACP), Diaphorina citri, an important citrus pest worldwide. We evaluated the lethal and sublethal effects of the residues from sprays of imidacloprid, fenpropathrin, horticultural mineral oil (HMO), pyrethrins, and spirotetramat on T. radiata at one, three, and seven days after application (DAA) to citrus trees in Southwest Florida. The effects of the residues from imidacloprid and fenpropathrin sprays were more detrimental than other insecticides. Parasitoid mortality from one to three-day-old residues averaged 90-96% for imidacloprid, 83-94% for fenpropathrin, 38-77% for pyrethrins, 43-44% for HMO, and 17-33% for spirotetramat. Parasitism by females that survived exposure was reduced by 71-88% from fenpropathrin, 28-59% from pyrethrins, 31-55% from imidacloprid, 44-4% from spirotetramat, and 39-11% from HMO compared to untreated females. The lethal and sublethal effects of all insecticides on T. radiata were significantly reduced at seven DAA, suggesting less impact on the establishment and performance of the parasitoid if releases are made after a week from spray application.