Residual toxicity of six reduced-risk insecticides to codling moth eggs and neonate larvae

Abstract: New classes of insecticides with novel modes of action have become available for codling moth control. To help growers better use these reduce-risk insecticides in theirmanagement programs, residual activities of six insecticides to codling moth eggs and larvae were evaluated with field-aged residue bioassays on apple leaves and fruit. Novaluron exhibited the highest and the longest residual activity on eggs laid on treated fruit or leaves. Methoxyfenoxide also demonstrated high levels of ovicidal activity but only for residue on fruit. For all insecticides evaluated, except novaluron, residues produced high levels of mortality of Cydia pomonella neonates for at least 14 days. Spinetoram was the most toxic followed by methoxyfenozide and chlorantraniliprole. Better knowledge of the relative toxicity of these new insecticides to various life stages will help determining optimal timing for application of these compounds.