LC50s of some Insecticides on Convergent Lady Beetles (Hippodamia convergens), are they compatible?

Research Poster
Rachel Bienemann
Luis Canas
Department of Entomology

Biological control is an important tactic of integrated pest management (IPM). One common commercially available biological control agent, the convergent lady beetle (Hippodamia convergens), provides effective control through predation on insect pests in both fields and greenhouses. Insecticides applied in these settings may also include synergists like piperonyl butoxide (PBO), and may be harmful to the lady beetles, but their effects are unknown. To test this, we used serial dilutions of insecticides with and without PBO. These were applied with a microapplicator as topical abdominal applications. Mortality was evaluated 72 hours, and we used SAS to make probit curves in which the LC50s were calculated. The LC50s of these insecticides produce a gradient, with some insecticides being more compatible with lady beetles. Convergent lady beetles are tolerant to thiamethoxam and are susceptible to chlorantraniliprole and lambda-cyhalothrin. Adding PBO resulted in higher toxicity. In the future, a broader range of insecticides will be tested.