Observation of population density of mosquito vectors in Yao Noi Island, PhangNga Province between 2012-2013

Abstract

Yao Noi Island locates in Koh Yeo Noi Sub-district, Koh Yeo District, PhangNga Province, Thailand. The geography of the island consist of mountains, brooks, marshes, ponds, rice fields, rubber plantations, mangoes, coconuts, and cashew nut orchards. Different ecological niches may affected on mosquito diversity. However, the mosquito researches in Koh Yao Noi Island had never been reported. Therefore, the effect of ecosystem diversity on any mosquitoes, especially the vector borne diseases in Yoo Noi Island were investigated. Three study sites, Ban Num Jeud village (village no. 3) where closed with rice fields. Ban Tha Khoo village (village no. 4) where closed with rubber plantation areas, and Ban An Poo village (village no. 7) where surrounded with rubber plantation areas were selected in this study. The distributions of several mosquito vectors in different sites were studied for 16 months during March 2012 to July 2013. The results indicated that the ecosystem diversity of Ban Tha Khao and Ban An Pao that closed with and located in rubber plantation areas were appropriate for malaria mosquito vectors to breed and disperse including Anopheles dirus complex, Anopheles minimus complex and Anopheles maculatus group. Culex spp., the vectors of Japanese encephalitis were observed in all three study sites, but Ban Num Jeud had the highest density, due to the rice fled ecosystem was the appropriate breeding site for them. In addition, Aedes spp., the dengue/chikungunya vectors and Mansonia spp. the filariasis vectors were observed in all three study sites. Armigeres app. were also found, but they were not the vector in these areas. Therefore, the ecosystem diversity in each three places significantly affected on mosquito vectors' growth and their dispersal behaviors to transmit the vector borne diseases.