Diversity Loss and Restructuring of the Microbiota in a Globally Invasive Lady Beetle  

Abstract The invasion success of Harmonia axyridis in North America and Europe has aroused a growing interest among students of invasion biology. This study was focused on the microbial community of H. axyridis with the aim of gaining insights into their potential roles in the invasion. We hypothesized that microbial communities of H. axyridis in the non-native range may decrease in diversity but restructured in composition as compared to those in the native regions. We collected lady beetle samples from eleven geographical areas across the native range mainland China and from seven areas in the non-native range USA. We applied next-generation amplicon sequencing to the samples to estimate microbial communities and examined differences in their composition and diversity between the host’s native and non-native ranges. We found that H. axyridis in the non-native range had lower microbial community richness and evenness than it had in the native range, but its microbiota composition of the amplicon sequence variants and genera differed markedly between the non-native and native ranges. The findings support our hypotheses concerning microbial community in H. axyridis across the native and non-native range. This study provides new information for our understanding of potential roles of the microbiota in the invasion success of H. axyridis.