The objective of this study was to evaluate the susceptibility of malaria vectors to pyrethroids and to detect the presence of kdr mutations in two peripheral agricultural sites in the city of Mouila. The study was conducted during the rainy season in 2017. Anopheles were collected at the larval stage by the "dipping" method and reared in the laboratory until the adult stage. Susceptibility tests were performed on the F0 generations according to the protocol recommended by WHO. The insecticides used were alphacypermethrin (0.05%, 0.25%, 0.50%), cyfluthrin (0.15%, 0.75%), etofenprox (0.5%, 5%) and bifenthrin 0.20%. The individuals of Anopheles gambiae s.l. from the tests were identified by the PCR technique. The survivor and dead mosquitoes were used to detect kdr mutations via PCR. The members of the An. gambiae complex of the study sites were composed of two species, An. gambiae s.s and An. coluzzii, with a predominance of An. gambiae s.s. The test results showed a resistance to alphacypermethrin (0.05%, 0.25% and 0.50%), cyfluthrin 0.15%, etofenprox 0.5% and bifenthrin 0.20% in both study sites and a suspicion of resistance to etofenprox 2.5% in the Moutassou site. Populations of An. gambiae s.l were susceptible to cyfluthrin 0.75% in these study sites (≤ 98%) and etofenprox 2.5% in the Mboukou site (100%). These two insecticides could be used for vector control after resistance has been observed to permethrin and deltamethrin (at low doses).
Coconut fiber is the substrate of choice for the production of plants in vegetable nursery above ground Gabon. However, procurement and production costs of the material remain high. This study conducted in the experimental area of the company Horta Gabon, located in the town of Akanda north of Libreville in Gabon, with the aims to test the possibility of substituting coconut fiber imported by coffee husks produced locally. Thus, through monitoring of the germination and vegetative behavior of Tomato seedlings (Lycopersicon esculentum) subject to various disinfection treatments, which have focused on the nature of disinfectant and the volumes applied, have showed that plants of tomato products on coffee husks disinfected 1.5 L of Metam Sodium (MS) and washed have better returns in terms of germination and development of tomato seedlings. These results indicate that the coffee husk could be an alternative substrate of coconut fiber without causing major imbalances.