Abstract: 【Aim】 This study aims to determine the effects of three low doses of fluvalinate on the quality of reared queens of the western honey bee, Apis mellifera. 【Methods】 Queens were caged to lay eggs for 8 h. The larvae hatched from those eggs were transplanted into queen cells for queen rearing, and fed with 2 μL syrup containing different concentrations of fluvalinate (0, 0.05, 0.5 and 5 mg/kg) since the 2nd day of larval stage using a micro sampling syringe injector. The numbers of capped queen cells after feeding for three days and emerged queens in the four groups were recorded, and the birth weight and thorax width of newly emerged queens were also measured. The expression levels of three genes (Vg, hex110 and hex70b) in queen ovaries were also assayed by quantitative real-time PCR (qPCR). 【Results】 The results showed that the proportion of capped queen cells with larvae in the 5 mg/kg fluvalinate group was significantly lower than those in the 0.05 mg/kg fluvalinate group, 0.5 mg/kg fluvalinate group and the control group (0 mg/kg fluvalinate), while there was no significant difference among the latter three groups. The emergence rates of reared queens in the 0.5 mg/kg fluvalinate group and 5 mg/kg fluvalinate group were significantly lower than those in the 0.05 mg/kg fluvalinate group and the control group. There was no significant difference in the birth weight and thorax width of reared queens among the four experimental groups. The results of qPCR analysis indicated that the relative expression level of Vg and hex110 in the ovary of queens reared in the 5 mg/kg fluvalinate group were significantly lower than those reared in the 0.05 mg/kg fluvalinate group, 0.5 mg/kg fluvalinate group and the control group, while there was no significant difference among the latter three groups. The relative expression levels of hex70b gene in the ovary of queens reared in the 5 mg/kg fluvalinate group and 0.5 mg/kg fluvalinate group were significantly lower than that reared in the control group, while the relative expression level of hex70b in the ovary of queens reared in the 0.05 mg/kg fluvalinate group was not significantly different from those in the other three groups. 【Conclusion】 The results indicate that the quality of reared queens of A. mellifera will be affected when the residue of fluvalinate in their food exceeds 0.5 mg/kg.

Key words: Apis mellifera, queen rearing, fluvalinate, ovary, gene expression