Chlorantraniliprole: Reduced-risk Insecticide for Controlling Insect Pests of Woody Ornamentals with Low Hazard to Bees

Abstract

Landscape professionals need target-selective insecticides for managing insect pests on flowering woody ornamentals that may be visited by bees and other insect pollinators. Chlorantraniliprole, the first anthranilic diamide insecticide registered for use in urban landscapes, selectively targets the receptors that regulate the flow of calcium to control muscle contraction in caterpillars, plant-feeding beetles, and certain other phytophagous insects. Designated a reduced- risk pesticide by the United States Environmental Protection Agency, it has a favorable toxicological and environmental profile, including very low toxicity to bees and most types of predatory and parasitic insects that contribute to pest suppression. Chlorantraniliprole has become a mainstay for managing turfgrass pests, but little has been published concerning its performance against the pests of woody ornamentals. Researchers evaluated it against pests spanning five different orders: adult Japanese beetles, evergreen bagworm, eastern tent caterpillar, bristly roseslug sawfly, hawthorn lace bug, oleander aphid, boxwood psyllid, oak lecanium scale (crawlers), and boxwood leafminer, using real-world exposure scenarios. Chlorantraniliprole’s efficacy, speed of control, and residual activity as a foliar spray for the leaf-chewing pests was as good, or better, than provided by industry standards, but sprays were ineffective against the sucking pests (lace bugs, aphids, or scales). Basal soil drenches in autumn or spring failed to systemically control boxwood psyllids or leafminers, but autumn drenches did suppress roseslug damage and Japanese beetle feeding the following year. This study indicates that chlorantraniliprole can be an effective component of integrated pest and pollinator management programs on woody ornamentals.