Keywords: 
• ethiprole /
• Apis mellifera L. /
• acute toxicity /
• chronic toxicity /
• oxidative stress

Abstract: As an alternative pesticide of fipronil, ethiprole has been registered and widely used in China. Ethiprole 10% suspension concentrate (SC) is the main commercialized product introduced by Bayer and shares a certain part of pesticide market. Up to now, toxicity evaluation of 10% ethiprole SC on non-target organisms was scarce. In the present study, the toxicities of 10% ethiprole SC to newly-emerged honey bees (Apis mellifera L.) were investigated by artificial feeding method under both acute (48 h) and chronic (14 d) exposure. Results showed that the 48 h-LC₅₀ of 10% ethiprole SC to honey bees was 0.21 (95% CI: 0.16~0.26) mg·L^-1 and relative LD₅₀was 5.0×10^-3 µg a.i.·bee^-1 (95% CI: 1.0×10^-3~1.0×10^-2 μg a.i.·bee^-1). The number of dead bees increased along with the prolongation of exposure when exposed to the sub-lethal concentrations of 10% ethiprole SC. In addition, during the chronic test, ethiprole induced significant changes in enzyme activities of SOD, CAT, GST and the content of MDA and GSH, which suggested the obvious oxidative stresses in bees. All these findings showed that ethiprole is highly toxic to bees and its application should be avoided during the flowering period, with the prevention of its drifting pollution in the field. Otherwise, newly-emerged bees have high sensitivity to chemicals and future research could explore the possibility of their applicaition as risk assessment indicator.