Mosquito vector diversity across habitats in central Thailand endemic for dengue and other arthropod-borne diseases - PubMed (original) (raw)
Mosquito vector diversity across habitats in central Thailand endemic for dengue and other arthropod-borne diseases
Panpim Thongsripong et al. PLoS Negl Trop Dis. 2013.
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.
Conflict of interest statement
The authors have declared that no competing interests exist.
Figures
Figure 1. Habitat degradation gradient.
Habitats found in central Thailand (top; photos by PT) represent landscape types with increasing degrees of anthropogenic modification (bottom, from left to right; drawings by Nancy Hulbirt, SOEST Illustrations) and biodiversity loss of flora and fauna, as seen by remote imaging (middle; images from NASA's Earth Observatory). Left to right: forest habitats with high biodiversity; agricultural habitats with mixed farming and forest patches to monocultures; rural habitats with some human dwellings, family farming and forest patches; suburban habitats with more human dwellings, some commercial activity, and fewer forest patches; urban habitats with dense residential and commercial activities and little to no forest patches.
Figure 2. Map of study area in Nakhon Nayok Province, Thailand.
Mosquitoes were collected in 24 sites representing six habitat types: Forest (F1 to F4), Fragmented Forest (FFR1 to FFR4), Rice Field (RF1 to RF4), Rural (RU1 to RU4), Suburban (SU1 to SU4), and Urban habitats (UR1 to UR2). Satellite imagery courtesy of the U.S. Geological Survey Land Remote Sensing Program (Landsat 8).
Figure 3. Mean abundance and 95% confidence intervals of female and male mosquitoes.
Mosquitoes were caught in the forest (F), fragmented forest (FFR), rice field (RF), rural, (RU) suburban (SU), and urban (UR) habitats in Nakhon Nayok Province, Central Thailand, during the rainy season of 2008. Each habitat type is represented by four replicate sites, except for the rice field habitat where only three sites were included in the analysis.
Figure 4. Average number of mosquitoes caught indoors and outdoors per trap and 95% confidence intervals.
Mosquitoes were caught in the forest (F), fragmented forest (FFR), rice field (RF), rural (RU), suburban (SU), and urban (UR) habitats in Nakhon Nayok Province, Central Thailand, during the rainy season of 2008. Each habitat type is represented by four replicate sites, except for the rice field habitat where only three sites were included in the analysis. Wilcoxon-Mann-Whitney rank sum test was used in the analysis. Stars indicates P = 0.029. P-value for the suburban and urban habitat were 0.057 and 0.686, respectively.
Figure 5. Rarefaction curves.
Calculated number of mosquito taxa as a function of number of sample collected from 24 sites representing six habitat types (solid lines) and 95% confidence intervals (shaded area) were plotted. The curves are used to determine whether the number of mosquitoes collected has reached an asymptote such that 100% of possible species were sampled. The technique also allows the calculation of species richness for a rarefied number of mosquitoes (species density or SD).
References
- Soule ME, Wilcox BA (1980) Conservation biology: an evolutionary-ecological perspective. Sunderland: Sinauer Associates. 395 p.
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical
Miscellaneous