The mosquito microbiome alters the physiological traits of medically important mosquitoes, which can scale to impact how mosquito populations sustain disease transmission. The mosquito microbiome varies significantly within individual mosquitoes and among populations, however the ecological and environmental factors that contribute to this variation are poorly understood. To further understand the factors that influence variation and diversity of the mosquito microbiome, we conducted a survey of the bacterial microbiome in the medically important mosquito, Aedes albopictus, on the high Pacific island of Maui, Hawai'i. We detected three bacterial Phyla and twelve bacterial families: Proteobacteria, Acitinobacteria, and Firmicutes; and Anaplasmataceae, Acetobacteraceae, Enterobacteriaceae, Burkholderiaceae, Xanthobacteraceae, Pseudomonadaceae, Streptomycetaceae, Staphylococcaceae, Xanthomonadaceae, Beijerinckiaceae, Rhizobiaceae, and Sphingomonadaceae. The Ae. albopictus bacterial microbiota varied among geographic locations, but temperature and rainfall were uncorrelated with this spatial variation. Infection status with an ampicomplexan pathosymbiont Ascogregarina taiwanensis was significantly associated with the composition of the Ae. albopictus bacteriome. The bacteriomes of mosquitoes with an A. taiwanensis infection were more likely to include several bacterial symbionts, including the most abundant lineage of Wolbachia sp. Other symbionts like Asaia sp. and several Enterobacteriaceae lineages were less prevalent in A. taiwanensis-infected mosquitoes. This highlights the possibility that inter-and intra-domain interactions may structure the Ae. albopictus microbiome.

Microorganisms live in close association with metazoan hosts and form symbiotic microbiotas that modulate host biology. Although the function of host-associated microbiomes may change with composition, hosts within a population can exhibit high turnover in microbiome composition among individuals. However, environmental drivers of this variation are inadequately described. Here, we test the hypothesis that this diversity among the microbiomes of Aedes albopictus (a mosquito disease vector) is associated with the local climate and land-use patterns on the high Pacific island of O 'ahu, Hawai 'i. Our principal finding demonstrates that the relative abundance of several bacterial symbionts in the Ae. albopictus microbiome varies in response to a landscape-scale moisture gradient, resulting in the turnover of the mosquito microbiome composition across the landscape. However, we find no evidence that mosquito microbiome diversity is tied to an index of urbanization. This result has implications toward understanding the assembly of host-associated microbiomes, especially during an era of rampant global climate change.