As regulatory pressure increases against neonicotinoid insecticides, New York growers are seeking alternative tools to manage the Colorado potato beetle (CPB), Leptinotarsa decemlineata. In 2024, we evaluated six non-neonicotinoid insecticides including abamectin, spinetoram, spinosad, cyantraniliprole, chlorantraniliprole, and lambda-cyhalothrin alongside the neonicotinoid acetamiprid as a performance reference. Using leaf-dip bioassays, we exposed field-collected populations, both 2nd instars and adults, to insecticide-treated foliage at the highest labeled foliar rates and quantified mortality. Additionally, defoliation was visually estimated after exposure to chlorantraniliprole only. Abamectin, cyantraniliprole, and acetamiprid provided 100% control of both larvae and adults across all tested populations. Chlorantraniliprole was highly effective against larvae and substantially suppressed feeding damage, while efficacy against adults was inconsistent, ranging from 5% to 10%, although defoliation remained < 10.5% for all populations, despite slower and reduced mortality among adults. In contrast, lambda-cyhalothrin showed inconsistent efficacy, with adult mortality ranging from 5% to 100%, and larval mortality ranging from 44% to 100%, suggesting localized resistance. Populations from Ulster and Columbia counties exhibited reduced susceptibility to spinetoram and spinosad, which may indicate overuse of Group 5 insecticides. The Ulster population exhibited 20% adult mortality to both spinetoram and spinosad, and reduced larval mortality (78% to spinetoram, 62% to spinosad). The Columbia population showed slightly reduced adult mortality to spinetoram (84%), while larvae were unaffected; for spinosad, larval mortality was slightly reduced (95%), and adults were fully susceptible. This ongoing study will help inform local and regional insecticide resistance management programs and guide future recommendations as regulatory policies evolve.
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