Efficacy of the Microbial Larvicide VectoMax<sup>®</sup>G against <i>Anopheles gambiae</i> s.l. and <i>Culex</i> spp. Larvae under Laboratory and Open Field Trial Experiments in the City of Yaoundé, Cameroon

Background: With the rapid expansion of insecticide resistance limiting effectiveness insecticide-based vector control interventions, integrated strategies associating larviciding could be appropriate to improve current efforts. The present experimental study assesses laboratory and field efficacy larvicide VectoMax®G on Anopheline Culicine larval stages in Yaoundé. Methods: effect VectoMax®G, a combination Bacillus thuringiensis var. israelensis (Bti) sphaericus (Bs), development was assessed during both open trial experiments. Laboratory experiments permitted evaluation five different concentrations with four replicates/experiments. were conducted Anopheles coluzzii “Ngousso” Culex quinquefasciatus strains. Open trials using sixteen plastic containers diameter 0.31 m buried an array rows 4 each. Distance between row 1 meter. This experiment test microbial under operational application conditions mosquito populations. Results: time induce 100% mortality after exposure serial varied according dose from - 12 hours for An. 6 9 Cx. Measurements residual activity indicated that all still active 35 days killed 86% larvae. Lethal killing 50% larvae estimated at 5.24 × 10-8 mg/m2 1.25 quinquefasciatus. lethal concentration inducing 95% 3.13 10-7 2.5 tests sub-lethal successfully gambiae s.l. within 24 hours, while spp. larvae, recorded 48 post-treatment. Natural recolonization water by 3 respectively treatment sublethal doses. Late instar 5 treatment. When jars treated reference dosage or supra doses observed six treatments. No pupae species found 7 Conclusions: high against Microbial larvicides such as controlling population particularly areas experiencing outdoor biting mosquitoes.