Emamectin benzoate-induced stress significantly affects the gut microbiome of adult Zeugodacus cucurbitae

The detoxification mechanisms in insects, which are triggered by insecticides, alter the diversity of their intestinal microorganisms. Emamectin benzoate is an insecticide used to control Zeugodacus cucurbitae (Coquillett), a globally significant pest. In this study, high-throughput sequencing, traditional isolation and culture methods, and single bacterial 16S rDNA sequencing were used to analyze the diversity and functional predictions of intestinal microbial communities in Z. cucurbitae adults exposed to emamectin benzoate. The results showed that the intestinal microorganisms of Z. cucurbitae on Cucumis sativus and Benincasa hispida var. chieh-qua were primarily composed of the phyla Proteobacteria and Bacteroidetes and genera Providencia, Enterobacter, Citrobacter, and Klebsiella. The relative abundances of Citrobacter, Enterobacter, Klebsiella, and Raoultella decreased with the induced stress, whereas those of Providencia and Pectobacterium increased. Diversity analysis revealed significant differences in the midgut flora of Z. cucurbitae before and after stress induction with emamectin benzoate.