Caragata, E. P. | bioRxiv Science

bioRxiv2025

The role of container periphyton as an oviposition attractant for female Aedes aegypti

BackgroundAedes aegypti mosquitoes use diverse chemosensory cues to select an oviposition site. These cues are thought to provide information on factors such as food availability, predators, pathogens, and competitors. Most research on the stimuli attracting female Ae. aegypti to oviposit in natural or artificial containers has focused on the properties of the vessel and water, such as size, color, water quality, concentration of dissolved organic matter, and microorganisms. One understudied aspect of oviposition containers is periphyton, the complex community of microorganisms that can grow on the inner walls of containers where gravid Ae. aegypti females lay their eggs. Periphyton can potentially act as an indicator of the containers suitability for females looking for an oviposition site, and as a source of food for future mosquito larvae. We were interested in understanding if container periphyton attracts gravid Ae. aegypti females for oviposition and to assess the microbial composition of the periphyton community. MethodsTo answer these questions, we conducted a series of attraction and oviposition assays and collected samples from the periphyton used in these assays for 16s rRNA fingerprinting. ResultsWe demonstrated that periphyton promotes oviposition by Ae. aegypti. Results from 16s rRNA fingerprinting of periphyton specimens revealed that these communities exhibit high complexity and contain microbial taxa from several classes, including Cyanobacteria, Proteobacteria, Anaerolineae, and Cytophagia. ConclusionsUnderstanding the chemosensory interactions between mosquitoes and periphyton involved in egg laying could prompt the development and formulation of novel attractants useful in mosquito control.

ecology↗

bioRxiv2023

Establishment and comparative genomics of a high-quality collection of mosquito-associated bacterial isolates -- MosAIC (Mosquito-Associated Isolate Collection)

Mosquitoes transmit medically important human pathogens, including viruses like dengue virus and parasites such as Plasmodium spp., the causative agent of malaria. Mosquito microbiomes are critically important for the ability of mosquitoes to transmit disease-causing agents. However, while large collections of bacterial isolates and genomic data exist for vertebrate microbiomes, the vast majority of work in mosquitoes to date is based on 16S rRNA gene amplicon data that provides limited taxonomic resolution and no functional information. To address this gap and facilitate future studies using experimental microbiome manipulations, we generated a bacterial Mosquito-Associated Isolate Collection (MosAIC) consisting of 392 bacterial isolates with extensive metadata and high-quality draft genome assemblies that are publicly available for use by the scientific community. MosAIC encompasses 142 species spanning 29 bacterial families, with members of the Enterobacteriaceae comprising 40% of the collection. Phylogenomic analysis of three genera, Enterobacter, Serratia, and Elizabethkingia, reveal lineages of mosquito-associated bacteria isolated from different mosquito species in multiple laboratories. Investigation into species pangenomes further reveals clusters of genes specific to these lineages, which are of interest for future work to identify functions underlying mosquito host association. Altogether, we describe the generation of a physical collection of mosquito-associated bacterial isolates, their genomic data, and analyses of selected groups in context of genome data from closely related isolates, providing a unique, highly valuable resource to investigate factors for bacterial colonisation and adaptation within mosquito hosts. Future efforts will expand the collection to include broader geographic and host species representation, especially from individuals collected from field populations, as well as other mosquito-associated microbes, including fungi, archaea, and protozoa.

microbiology↗