Comparative toxicity and application efficacy of imidacloprid, chlorantraniliprole, and cypermethrin, against Brevicoryne brassicae (Hemiptera: Aphididae) infesting cruciferous crops

This study investigates the comparative toxicity of 3 insecticides, imidacloprid, chlorantraniliprole, and cypermethrin against the cabbage aphid, Brevicoryne brassicae (Linnaeus) (Hemiptera: Aphididae). Toxicity was evaluated using 2 field-relevant application methods, leaf spray and particle film, while a separate insect dip bioassay was conducted independently as a comparative direct-contact exposure test. All insecticides exhibited concentration and time-dependent mortality, with differences observed among application methods. The residual exposure assays (leaf spray and particle film) showed that efficacy increased with exposure duration, while the insect-dip method produced higher apparent mortality owing to full-body contact. Among the tested compounds, imidacloprid demonstrated the highest overall toxicity, followed by chlorantraniliprole and cypermethrin. These results emphasize that application method and formulation characteristics strongly influence apparent toxicity and should be considered when comparing insecticide performance. The findings provide baseline information useful for refining contact-bioassay protocols and guiding insecticide selection in integrated pest-management programs targeting B. brassicae.