Fig. 2

Factors that influence symbiotic bacterial communities. Insect samples collected in the same province of China or belonging to the same superfamily are grouped. The sample locations are divided into southeast and northwest of China according to the Heihe-Tengchong Line. The superfamilies are classified into Cimicomorpha and Pentatomomorpha according to their phylogenetic relationship. The alpha diversity results of symbiotic bacterial communities are shown by the Shannon index (a, b) and are tested the differences by the Kruskal–Wallis test. The beta diversity results are calculated by the weighted Unifrac distance and displayed using the PCoA plot, the confidence ellipsoids (confidence level = 0.95) of different locations are provided by dotted lines (c). The sample groups are marked according to insect superfamilies (colors) or sample locations (geometrical shape). The Mantel test (d, e) and the Procrustes test (f, g) are displayed at the bottom half. If p < 0.05, it could be regarded that the symbiotic bacterial communities are related to the host genetic distance or the sample geographical distance