Abstract

Insects are associated with diverse microbial communities that can have substantial effects on hosts. Here, we characterized the bacterial communities in the Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae), a major vector of the devastating pathogen “Candidatus Liberibacter asiaticus,” which causes citrus Huanglongbing (HLB). In total, 256 ACP individuals across 15 field sites and one laboratory population in China were sequenced. The results showed that the bacterial community diversity was the highest in the Guilin population (average Shannon index, 1.27), and the highest value for richness was found in the Chenzhou population (average Chao1 index, 298). The bacterial community structures of the field-collected populations were significantly different, and all of them harbored Wolbachia, which was assigned to strain ST-173. Structural equation models revealed that the dominant Wolbachia strain had a significantly negative correlation with the annual mean temperature. In addition, the results obtained with populations infected with “Ca. Liberibacter asiaticus” indicated that in total, 140 bacteria could be involved in interactions with this bacterium. The ACP field populations harbored a more diverse bacterial community than the laboratory population, and the relative occurrences of some symbionts differed significantly. However, the bacterial community of the ACP laboratory colony was connected in a more complex network structure (average degree, 54.83) than that of the field populations (average degree, 10.62). Our results provide evidence that environmental factors can influence the bacterial community structure and bacterial relative abundance in ACP populations. This is likely due to the adaptation of ACPs to local environments.IMPORTANCE The Asian citrus psyllid (ACP) is an important vector of the HLB pathogen, which is a major threat to citrus production around the world. Bacterial communities harbored by insects could be affected by dif