Fig. 3

Deprivation and supplementation of Sphingomonas in the gut of the IMI-S and IMI-R strains and detection of Sphingomonas in nine field populations of Aphis gossypii collected in 2019. A Experimental design: apterous adult aphids of the IMI-S and IMI-R strains were treated with ampicillin for 7 days to deprive Sphingomonas or treated with Sphingomonas for 7 days for Sphingomonas supplementation. Afterward, the guts of apterous aphids from the IMI-S strain or IMI-R strain were dissected for DNA extraction and then for 16S rDNA sequencing. In addition, after treatment with ampicillin or Sphingomonas for 7 days, the changes in the susceptibility of the IMI-S and IMI-R strains to imidacloprid were determined by the leaf-dipping method. B Histogram showing the relative abundance of the 10 most dominant bacterial genera of the gut symbiont in the IMI-R and IMI-S strains. The abundance of Sphingomonas in the gut of the IMI-R and IMI-S strains (C, D). The different lowercase letters (a, b, c) on the bars indicate significant differences according to one-way ANOVA (n = 5, P < 0.05, Tukey’s test). The analysis of alpha diversity indices of species for the gut symbiont in the IMI-S and IMI-R strains, Chao 1 index (E, F) and Shannon index (G, H) based on the Wilcoxon test, n = 5