Various routes of formulated insecticide mixture whole-body acute contact toxicity to honey bees (Apis mellifera)

• DOI: 10.1016/j.envc.2021.100408
• Publication Date: 2021-12-01T04:24:06Z
• Authors: Joseph Belsky; David J. Biddinger; Nicholas Seiter; Neelendra K. Joshi
• Keywords: Fipronil; Cyhalothrin

Honey bees, Apis mellifera (Linnaeus) are crucial pollinators, however large overwinter losses of managed hives and declines in feral colonies have occurred since 2006. Increased insecticide use the introduction new classes been proposed as factors contributing to these declines. Previous studies demonstrated contact toxicity single active ingredient insecticides honey bees. However, field realistic formulated (pre-mix) mixtures containing multiple ingredients (each with a different mode action) bees has not thoroughly assessed. Here, we simulate whole body spray applications made at low label recommended rates thiamethoxam + lambda-cyhalothrin, imidacloprid beta-cyfluthrin, chlorantraniliprole lambda-cyhalothrin methoxyfenozide spinetoram under three scenarios crops: (1) continuous exposure, (2) spray-only (3) residual exposure. A customized tower laboratory setting was used apply lowest dose Environmental Protection Agency regulated each insecticide. Acute determined by screening resulting mortality up 96-hours post treatment. Mortality varied significantly between treatments all evaluation periods for experiments except For beta-cyfluthrin resulted 80–90% 48-hours, while observed close complete treatments. This difference onset highlights importance extended observation beyond 48-hours USDA-EPA. Our finding overall high demonstrates comparing both combined individual determining risk