Abstract

This study assessed the dynamics of mosquito larval populations and species diversity in paddy fields in Alappuzha district, Kerala, and investigated the pesticide resistance of Culex tritaeniorhynchus and Culex sitiens to malathion and deltamethrin. Mosquito larvae were gathered biweekly over the three-month study duration. The density and diversity of research were evaluated independently for each category using the traditional diversity index. The World Health Organization (WHO) tube test was utilized to evaluate the pesticide susceptibility of adult Culex sitiens and Culex tritaeniorhynchus mosquitoes to malathion and deltamethrin. A total of 2,426 immature mosquitoes were captured. Two genera and ten species were gathered and identified as follows: Anopheles barbirostris, Anopheles peditaeniatus, Anopheles subpictus, Anopheles vagus, and five species of Culex: Cx. bitaeniorhynchus, Cx. gelidus, Cx. quinquefasciatus, Cx. sitiens, Cx. tritaeniorhynchus, and Cx. vishnui. Cx. tritaeniorhynchus exhibited intermediate tolerance to both malathion and deltamethrin, but Cx. sitiens shown great sensitivity to both pesticides under identical exposure settings. The increasing population of Culex tritaeniorhynchus mosquitoes in rice farming regions may present considerable threats to human health. An improved understanding of mosquito variety and pesticide resistance would facilitate the formulation of successful, regionally tailored vector control methods.

Key words: Paddy field, Cx. tritaeniorhynchus, Cx. sitiens, pesticides, resistance