Larvicidal activity of Pseudocalymma alliaceum and Allium sativum against Culex quinquefasciatus (Say)

The larvicidal activity of the plant extracts Pseudocalymma alliaceum and Allium sativum were determined against Culex quinquefasciatus. The hexane extract of P. alliaceum and the petroleum ether extract of A. sativum exhibited larvicidal efficacy against Cx. quinquefasciatus larvae. Extracts of P. alliaceum resulted in concentrations that produced 50% mortality LC₅₀ and LC₉₀ values of 2.49 and 15.06 ppm, respectively, after 24 h and 1.16 and 8.45 ppm after 48 h. Extracts of A. sativum resulted in LC₅₀ and LC₉₀ values of 8.38 and 29.15 ppm after 24 h and 7.28 and 44.19 ppm after 48 h of exposure, respectively. The results indicate that the plant extract component(s) present in the hexane extract of P. alliaceum leaves demonstrated greater potential as an efficient larvicide than A. sativum against Cx. quinquefasciatus.     

Larvicidal efficacy of Aloe barbadensis and Cannabis sativa against the malaria vector Anopheles stephensi (Diptera: Culicidae)

Anopheles stephensi is the primary vector of malaria, an endemic disease in India. An effort to control An. stephensi larvae by leaf extracts of Aloe barbadensis (Liliaceae) and Cannabis sativa (Moraceae) was made under laboratory conditions. A carbon tetrachloride extract of A. barbadensis was the most effective of all the extracts tested for larvicidal activity against the anopheline larvae, with LC₅₀ 15.58 and 8.04 p.p.m. after 24 and 48 h of exposure, respectively. Thus, the leaf extract of A. barbadensis has active components that could be useful as a larvicide of ecocongenial nature against malaria vectors.