Efficacy of several insecticides alone and with horticultural mineral oils on light brown apple moth (Lepidoptera: Tortricidae) eggs

The aim of the research was to identify efficacious and less environmentally harmful treatments than the standard chlorpyrifos sprays used for the control light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), eggs on nursery stock. A series of dip experiments showed a range of responses when comparing the efficacy of insecticides on egg hatch of E. postvittana. The insecticides that compared most favorably with chlorpyrifos were lamda-cyhalothrin and gamma-cyhalothrin, and thiacloprid. Indoxacarb, novaluron, and spinosad caused significant mortality only when combined with All Seasons mineral oil. All Seasons, showed ovicidal properties when evaluated alone and demonstrated adjuvant properties when combined with the above-mentioned insecticides, except gamma-cyhalothrin and thiacloprid. Several other horticultural mineral oils performed similarly, except the efficacy of spinosad varied with the oil product used, suggesting that the oil type selected is important for some insecticide and oil combinations. Several insecticides evaluated in this study are likely candidates for further work to develop treatments against E. postvittana eggs on nursery plants. Mineral oils are ovicidal and combinations with insecticides are likely to be advantageous.