Journal of Entomological Research

The study examined the acute toxicity of lambda-cyhalothrin, a commonly used pesticide, on Asian honeybee (Apis cerana) adult workers and larvae. The research assessed mortality rates following exposure to various doses of lambda-cyhalothrin over a 24 h period. For adult worker bees, doses between 0.054 - 0.072 μg/bee and 0.090 -0.100 μg/bee led to mortality rates exceeding 50%, with a maximum mortality of 96.54% at 0.100 μg/bee. Probit analysis estimated an LD₅₀ of 0.04 μg. In oral exposure tests on adult bees, doses between 0.065 -1.050 μg/bee caused more than 50% mortality, with a maximum of 85.70% at 1.05 μg/bee. The LD₅₀ for oral exposure was 0.501 μg. For A. cerana larvae, doses between 0.75 -1.50 μg/bee resulted in over 50% mortality, with a maximum of 96.21% at 1.50 μg/larvae. Probit analysis estimated an LD₅₀ of 0.63 μg. While limited previous research exists on the oral dose mortality of A. cerana larvae, this study highlighted the elevated susceptibility of larvae to lambda-cyhalothrin, affecting their development into pupae.