Mosquito Vector Diversity across Habitats in Central Thailand Endemic for Dengue and Other Arthropod-Borne Diseases

Abstract

Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand.

Mosquito vector‐associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod‐borne diseases

“…Adult mosquito collection and habitat characterization was described in a previous study (Thongsripong et al., 2013). In short, we collected adult mosquitoes using a combination of trap types (BG sentinel, Mosquito Magnet, CDC light trap, and CDC backpack aspirator) during the rainy season of 2008 from different habitat types ranging from forest to urban in Nakhon Nayok, a small province situated in central Thailand approximately 60 km northeast of Bangkok.…”

“…In short, we collected adult mosquitoes using a combination of trap types (BG sentinel, Mosquito Magnet, CDC light trap, and CDC backpack aspirator) during the rainy season of 2008 from different habitat types ranging from forest to urban in Nakhon Nayok, a small province situated in central Thailand approximately 60 km northeast of Bangkok. Over 83,000 adults mosquitoes were collected as described in the previous study (Thongsripong et al., 2013). Trap collections from each site were transported on dry ice to a local field station.…”

“…Upon arrival, mosquitoes were sorted immediately and then stored at −20°C for less than one month before they were transported on dry ice to Mahidol University in Bangkok. The female mosquitoes were identified to species using available morphological keys (Rattanarithikul, Harbach, Harrison, Panthusiri, & Coleman, 2007; Rattanarithikul, Harrison, Panthusiri, & Coleman, 2005; Rattanarithikul, Harrison, Panthusiri, Peyton, & Coleman, 2006; Rattanarithikul et al., 2010; Rattanarithikul, Harbach, et al., 2005; Rattanarithikul, Harrison, Harbach, et al., 2006; Thongsripong et al., 2013). Adult females used in this study were not visibly blood‐engorged.…”

“…Of the over 100 mosquito taxa collected, whose mosquito community composition varied significantly across habitat (Thongsripong et al., 2013), we subsampled ten mosquito pools of the species Ae. aegypti, Ae.…”

“…quinquefasciatus , amongst other Culex spp., locally transmits Japanese encephalitis, an important cause of encephalitis in Thailand (Olsen et al., 2015). In characterizing mosquito species and their diversity across habitats, we have observed that mosquito overall diversity decreased with increasing relative abundance of several medically important invasive mosquito vector species and degree of human habitat modification (Thongsripong et al., 2013). In this study, we describe the microbial communities of these disease vectors in the subset of habitats where they were found in our previous study, that is, in rural, suburban, and urban habitats.…”