Spatial and temporal variations on the coexistence of Aedes and Culex larvae in Southern Thailand

ABSTRACT

This study investigated spatial and temporal variations on the coexistence of Aedes aegypti, Aedes albopictus, and Culex larvae in five subdistricts in Nakhon Si Thammarat, Thailand. We tested two main hypotheses on the spatial and temporal coexistence of mosquito larvae (1) condition-specific competition and (2) spatial variation among the five subdistricts. We compared the number of positive houses, positive containers, mosquito coexistence during both the wet and dry seasons. The results showed that from a total of 1,072 positive containers collected in both seasons, Ae. albopictus larvae were found in the highest number of containers (745 containers), followed by containers with Ae. aegypti larvae (283 containers) and containers with Culex larvae (254 containers). During the wet season, there were higher numbers of positive houses, positive containers, and containers with only Ae. albopictus larvae than during the dry season. On the other hand, during the dry season when the water containers were very scarce, there were higher numbers of containers with Culex larvae, and containers held more than one type of mosquito larvae. This indicates that both temporal and spatial variations may contribute to the local coexistence of Aedes and Culex mosquito larvae species in Lansaka District areas in Thailand.(AU)