COMPARATIVE SUSCEPTIBILITY TO LAMBDACYHALOTHRIN OF TWO AEDES AEGYPTI POPULATIONS FROM COUFFO DEPARTMENT AND ITS IMPLICATIONS FOR DENGUE VECTOR CONTROL IN SOUTH-WESTERN BENIN

Nazaire Aïzoun*, Géorcelin Alowanou, Habib Tamègnon, Alda Yémadjè, Daniel Chougourou

Aedes aegypti is a vector of viruses that negatively impact human health. The understanding of the factors which influence vector susceptibility to insecticide is important. The current study aimed to compare susceptibility to lambdacyhalothrin of two Aedes aegypti populations from Couffo department in South-western Benin, regarding mosquito sex, physiological status, and mosquito age. Larvae and pupae of Aedes aegypti mosquitoes were collected from April to July 2024 during the great rainy season in the breeding sites in Couffo department. The WHO susceptibility tests were conducted on unfed male and female mosquitoes aged 2-5 days old. WHO susceptibility tests were also conducted on unfed, blood fed and gravid female mosquitoes aged 2-5 days old. These susceptibility tests were also conducted on unfed, blood fed and gravid female mosquitoes aged 20 days old. The results showed that Aedes aegypti male adult were not more susceptible than the females. There was no increasing in vector susceptibility to lambdacyhalothrin after females had taken their blood meals. There also was no increasing in vector susceptibility to lambdacyhalothrin after females possess eggs in their abdomen. The results also showed that more mosquitoes were old more they were susceptible to lambdacyhalothrin. Many factors influence vector susceptibility to insecticide. Among these factors, there are mosquito sex, physiological status and mosquito age. Therefore, it is useful to respect the WHO criteria in the assessment of insecticide susceptibility tests in human disease vectors including the dengue vectors.