<b>Effects of tefluthrin and guadipyr on midgut bacteria of adult </b><i><b>Apis mellifera</b></i>

This study aims to analyze whether heptafluthrin and pentylpyrazine affect the gut microbes’ structure and metabolism of adult Apis mellifera ligustica, enrich the mechanism of insecticide action, and have practical significance for bee protection. [Methods] In this study, Apis mellifera were fed with 1) control sugar water, 2) tefluthrin sugar water or 3) guadipyr sugar water. After 10 days, the genomic DNA of gut bacteria were extracted. We use high-throughput sequencing to determine whether tefluthrin and guadipyr treated would influence the diversity and abundance of gut bacteria. 【Results】There were 20 species of gut bacteria in A. mellifera, which belonged to 5 phyla, 6 classes, 11 orders, 11 families and 15 genera. The dominant phyla of the gut bacteria are Proteobacteria and Bacteroides. Compared with the control group, the structure of the bacteria flora in the deltamethrin-treated group and tefluthrin-treated group changed. At the phylum level, the relative abundance of Cyanobacteria decreased significantly (P < 0.05). At the genus level, the relative abundance of the Bartonella and Serratia in the tefluthrin group increased significantly (P < 0.05). The relative abundance of Gilliamella and Frischella increased significantly (P < 0.05) in the guadipyr-treated group, and the relative abundance of norank_o_Chloroplast and Enterobacteria decreased significantly (P < 0.05). The prediction of COG function showed that the metabolism of gut microbes changed after tefluthrin treatment, but there was no change after guadipyr treatment.【Conclusion】Exposure of bees to tefluthrin and guadipyr can change the structure and function of gut bacteria of A. mellifera. The effect of tefluthrin on gut bacteria of A. mellifera is greater than that of guadipyr.