Comparison of susceptibility to deltamethrin in female adult Anopheles gambiae s.l. from Dogbo district with their F1 progeny susceptibility in South-Western Benin, West Africa

The current study was aimed to compare the susceptibility to deltamethrin in female adult Anopheles gambiae s.l. from Dogbo district with their F1 progeny susceptibility in South-Western Benin, West Africa. Larvae and pupae of Anopheles gambiae s.l. populations were collected from the breeding sites in Couffo department in 2020 and reared up for obtaining F1 progeny. Female adult An. gambiae s.l. mosquitoes were also collected from window traps put on windows of rooms in Dogbo district surveyed. An. gambiae s.l. mosquitoes were collected from March to July and August to November 2020 during the rainy season in the locations of Ayomi, Dévé, Honton, Lokogohoué, Madjrè and Totchangni. Female adult An. gambiae species collected from window traps were morphologically identified using morphological keys and then transferred into mosquito cages for WHO bioassays performed with impregnated papers of deltamethrin (0.05%). WHO bioassays were also performed with F1 progeny. The physiological age of female adult An. gambiae s.l. collected from window traps was determined through dissection using Detinova method. The results showed that the mortality rates recorded with female adult An. gambiae s.l. mosquitoes collected from window traps were higher than those obtained with their F1 progeny An. gambiae s.l. mosquitoes obtained after reproduction of parent mosquitoes. The current study clearly shows that changes in mosquito physiology occur with senescence.