Culex pipiens and Culex restuans larval interactions shape the bacterial communities in container aquatic habitats

Authors: NJOROGE, TERESIA - Indiana University School Of Medicine; BERENBAUM, MAY - University Of Illinois; STONE, CHRISTOPHER - University Of Illinois; KIM, CHANG-HYUN - University Of Illinois; Dunlap, Christopher; Muturi, Ephantus

Submitted to: FEMS Microbes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2024
Publication Date: 2/12/2024
Citation: Njoroge, T.M., Berenbaum, M.R., Stone, C.A., Kim, C., Dunlap, C.A., Muturi, E.J. 2024. Culex pipiens and Culex restuans larval interactions shape the bacterial communities in container aquatic habitats. FEMS Microbes. https://doi.org/10.1093/femsmc/xtae002.
DOI: https://doi.org/10.1093/femsmc/xtae002

Interpretive Summary: Water-filled natural and artificial containers serve as important larval habitats for diverse mosquito species including vectors of West Nile virus (WNV). Mosquito larvae in these habitats feed on microorganisms associated with decaying organic matter. Some of the ingested microorganisms colonize the mosquito gut and provide many essential benefits to the host. Understanding how larvae of different mosquito species interact with these microorganisms could provide novel insights into how these microbes could be harnessed for mosquito control. We investigated how larvae of two mosquito species that vector WNV affect the composition and diversity of microorganisms in water-filled artificial container habitats. We also investigated how interactions among larvae of the two mosquito species influence the composition and diversity of microorganisms that colonize their bodies. The microorganisms present in the water samples with mosquito larvae were different from those present in water samples without mosquitoes. Mosquito larvae enhanced the abundance of some microorganisms and suppressed the abundance of others. Additionally, larvae of the two mosquito species had similar microorganisms when reared together and different microorganisms when reared separately. These findings demonstrate that mosquito larvae may alter the composition of microorganisms present in the larval habitats, which may in turn influence the type of microbes that colonize their bodies. Differences in microbial communities resulting from interactions among larvae of the two mosquito species may be one of the key factors responsible for individual and population variation in the ability of the two mosquito species to transmit WNV.

Technical Abstract: Container aquatic habitats host a community of aquatic insects, primarily mosquito larvae that browse on container surface microbial biofilm and filter-feed on microorganisms in the water column. We examined how the bacterial communities in these habitats respond to feeding by larvae of two container-dwelling mosquito species, Culex pipiens and Cx. restuans. We also investigated how the microbiota of these larvae is impacted by intra- and interspecific interactions. Microbial diversity and richness were significantly higher in water samples when mosquito larvae were present, and in Cx. restuans compared to Cx. pipiens larvae. Microbial communities of water samples clustered based on the presence or absence of mosquito larvae and were distinct from those of mosquito larvae. Culex pipiens and Cx. restuans larvae harbored distinct microbial communities when reared under intraspecific conditions and similar microbial communities when reared under interspecific conditions. These findings demonstrate that mosquito larvae play a major role in structuring the microbial communities in container habitats and that intra- and interspecific interactions in mosquito larvae may shape their microbiota. This has important ecological and public health implications since larvae of the two mosquito species are major occupants of container habitats while the adults are vectors of West Nile virus.