The potential of mineral oils alone and with reduced rates of insecticides for the control of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), on nursery plants

Abstract

The aim of the research was to identify alternatives to chlorpyrifos for the control of light brown apple moth, Epiphyas postvittana, on nursery and ornamental plants. Viburnum tinus L., a commonly grown nursery plant, were infested with E. postvittana eggs, sprayed to run-off and mortality recorded. Several treatments were identified as equally efficacious as the standard chlorpyrifos spray (500 μg/l). The insecticides that compared most favorably with chlorpyrifos were λ-cyhalothrin and γ-cyhalothrin. Four horticultural mineral oils demonstrated good ovicidal properties when evaluated alone versus when combined with reduced rates of the above insecticides or spinosad, imidacloprid or thiacloprid. The response of some insecticide and horticultural mineral oil combinations varied, suggesting that the oil selected may be important. Chlorpyrifos, λ-cyhalothrin, γ-cyhalothrin and spinosad provided similarly high levels of residual control of neonates for up to 10 d from application. Mixtures of UltraPure, an nC21 horticultural mineral oil, with reduced rates of the above insecticides maintained residual efficacy. Alternative treatments evaluated in this study may provide a high level of E. postvittana control through egg mortality and residual effects on emerging neonates over the hatching period. Field trials are required to verify the potential of these alternatives for commercial application.