Lygus Bug and Alfalfa Weevil Insecticide Resistance in the Pacific Northwest

Abstract In Washington State, east of the Cascade Mountains, alfalfa is grown for seed and forage. Alfalfa weevils are the primary defoliators of alfalfa grown for forage and seed, and Lygus bugs are the key direct pest in alfalfa seed production in the Pacific Northwest. Both alfalfa weevil and Lygus bugs are controlled by insecticide applications. Some levels of insecticide resistance have been observed in recent years. This article reports on a series of experiments that were conducted to quantify the resistance status of Lygus bugs and alfalfa weevils to several insecticides in Washington State. Earn 1.5 CEUs in Integrated Pest Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning‐Center/Courses .