Seasonal variation of Japanese encephalitis vector mosquito’s populations in vulnerable areas of Northern parts of West Bengal, India

Abstract

Vector control is one of the major aspects for prevention and control of Japanese encephalitis (JE). Information on population dynamics and impact of environmental factors on it are important for formulation of vector control measures. Present study was designed to study species abundance, population dynamics and impact of environmental factors on JE vectors in northern part of West Bengal. Immature and mature stages were collected on monthly basis and identified morphologically. Per dip density and man hour density were calculated and analyzed using SPSS software to determine the impact of environmental factors on JE vector. A total of 43960 mosquitoes were collected and Culex were predominant genus. Four JE vectors species were identified - Cx. tritaeniorhynchus, Cx. gelidus, Cx. pseudovishnui, and Cx. vishnui. Pronounced monthly variation was observed with low density in winter and high in monsoon. Abundance of JE vectors were positively correlated with temperature, relative humidity and rainfall in study areas. This study findings may serve as baseline data on population dynamics of JE vector and impact of environmental factors on it which may be useful for formulation of effective vector control strategies. Abundance of Culex vectors clearly indicate possible threat of JE incidence in the study areas.