Larvicidal potential of some Cassia species against Aedes aegypti and Anopheles stephensi

The larvicidal potential of petroleum ether, chloroform, ethyl acetate and methanol extracts of leaves and seeds of four traditionally important Cassia species viz., Senna alata, Senna auriculata, Senna tora and Cassia fistula was studied against the early fourthinstar larvae of two important mosquito vectors, Anopheles stephensi and Aedes aegypti. The leaf and seed extracts of four selected plants at 1000, 500, 250 and 125 ppm caused a considerable mortality in the selected mosquito larvae and the seed extracts were more potent than leaf extracts. Among the tested extracts, the petroleum ether seed extract of C. fistula showed the highest larvicidal activity at LC₅₀ value of 715.11 ppm (12 h), 320.71 ppm (24 h) and at LC₉₀ of 1780.12 ppm (12 h), 954.25 ppm (24 h) against A. aegypti. Similarly, in A. stephensi, highest larvicidal activity was observed on treatment with petroleum ether seed extract of C. fistula at LC₅₀ concentration of 834.74 ppm (12 h), 408.48 ppm (24 h) and at LC₉₀ value of 2079.88 ppm (12 h), 1430.45 ppm (24 h). However, in the case of leaf extracts, the methanol extract of S. tora demonstrated highest activity at LC₅₀ of 973.09 ppm, 659.13 ppm and LC₉₀ of 1870.34 ppm, 1336.39 ppm against A. stephensi after 12 h and 24 h, respectively. The results suggested that the petroleum ether seed extract of Cassia fistula can be used efficiently for controlling the tested mosquito vector species in an eco-friendly manner