Larvicidal and oviposition-deterrence activities of four local plant extracts from Burkina Faso against Anopheles gambiae S. l. (Diptera: Culicidae)

摘要

Mosquitoes have developed resistance to various synthetic insecticides, making their control increasinglydifficult. As part of the search for natural biocides, an alternative to synthetic insecticides, larvicidal andoviposition-deterrence activities of ethanol, acetone and hexane extracts of Lantana camara L., Hyptissuaveolens Poit., Ocimum canum Sims. and Hyptis spicigera Lam. on sensitive and local strains of An.gambiae s. l. were evaluated.Larvicidal activity was assessed according to the WHO standard protocol. Oviposition deterrence activitywas evaluated using gravid Anopheles gambiae s. l. Phytochemical screening of these plant extractsrevealed the presence of terpenes, tannins, saponins, alkaloids, flavonoids, steroids and phenols. The LC50and LC90 values determined for these extracts varied according to plants and solvents. The hexane extractsof L. camara were the most toxic to An. gambiae local strain larvae with LC50 value of 20.19 ppm (95%CL=14.35-26.67) and LC90 value of 49.29ppm (95% CL=37.13-65.40). Extracts also showed highoviposition- deterrence of An. gambiae. For L. camara acetone extract, The average number of eggs was0 ± 0, 10 ± 1 and 128 ± 16 eggs in treated plastic cups while in control plastic cups it was 258 ± 36, 224 ±55 and 256 ± 31 eggs at 100 ppm, 500 ppm, 1000 ppm respectively. Our results indicated that these extracts,mainly extracts of Lantana camara, could be used for An. gambiae control as ecofriendly natural products.