The Study of Abundance and Geographic Distribution of Mansonia Vectors in Urban Fringe and Forest Fringe Areas in Bo Rai District, Trat Province

Abstract

Land use such as several constructed pools available for water supply and agricultural practices can influence changes in vector ecology. This study aimed to assess abundance and geographic distribution of Mansonia vectors in urban fringe and forest fringe areas of Borai District, Trat Province by using two study sites that were selected based on larval habitat assessment, land survey, and land use map. Study site A had a constructed pool in urban fringe as highly potent as breeding site with high density of water hyacinths. Study site B had a constructed pool in forest fringe as moderately potent as breeding site with moderate density of water lettuces. The periodic assessments of abundance (species and number) and man landing rate (MLR) for adult female populations of Mansonia vectors and larval abundance were done in May, August and November 2015. Findings revealed that both study sites A and B had more abundant Ma. uniformis as predominant species (p_i= 0.753 and 0.638, respectively). Its counterparts had lesser extent by Ma. indiana, Ma. annulata, Ma. annulifera, Ma. dives, and Ma. bonneae. There was a significant difference in MLRs (mean±SD mosquito per night per person) for Ma. uniformis observed between study sites A (12.04±6.15) and B (1.25±0.98) (P=0.040). Meanwhile there was no significant difference in larval abundances between study sites A (8.13±8.66 larvae per one kilogram of water hyacinths) and B (1.0±1.06 larvae per one kilogram of water lettuces). Such findings suggest that Ma. unifomis was adapted well to local environments of urban fringe and forest fringe areas. Based on 2015-2018 land use data, the significance was that more constructed pools available for water supply and agricultural practices, more increased Mansonia vector productivity and risk for human-vector exposure in Borai District, Trat Province.