Larvicidal activity of indigenous plant extracts on the rural malarial vector, Anopheles culicifacies Giles. (Diptera: Culicidae)

Vector control is one of the most important components in combating vector-borne diseases throughout the world. Application of insecticides is a widely known and popular vector control strategy. The objective of the present study was to evaluate the larvicidal activity of the hexane, diethyl ether, ethyl acetate and acetone extracts of <em>Abutilon</em> <em>indicum</em>, <em>Hyptis</em> <em>suaveolens</em> and <em>Leucas</em> <em>aspera</em> against third-stage larvae of <em>Anopheles</em> <em>culicifiacies</em>. The results clearly suggest that all three selected plant extracts exhibited moderate larvicidal activity after 24, 48 and 72 h at 250, 500, 750 and 1000 ppm; the lethal concentrations (LC) at 50% and 90% of <em>A</em>. <em>indicum</em>, <em>H</em>. <em>suaveolens</em> against third instar larvae at 24, 48 and 72 h (hexane, diethyl ether, ethyl acetate and acetone) were as follows: <em>A</em>. <em>indicum</em>, LC₅₀=1031.65, 949.18, 833.58 and 673.68 ppm; LC₉₀=2215.87, 2234.39, 2152.97 and 2455.10 ppm; <em>H.</em> <em>suaveolens</em>, LC₅₀=423.00, 347.50, 236.58 and 217.24 ppm; LC₉₀=1431.91, 1292.15, 1138.49 and 1049.27 ppm and <em>L</em>. <em>aspera</em>, LC₅₀=559.77, 401.56, 299.71 and 263.01 ppm; LC₉₀=1400.80, 1549.31, 1157.96 and 1108.72 ppm at 24 h, respectively. Overall, the highest larvicidal activity was observed with <em>H</em>. <em>suaveolens</em> extract followed by <em>L</em>. <em>aspera</em> and <em>A</em>. <em>indicum</em> at various concentrations at 48 and 72 h, respectively. The objective of this investigation was an attempt to search for a user- and eco-friendly vector control agent. The study proved that the selected plant leaf extracts could serve as potent larvicidal agents against <em>A</em>. <em>culicifacies</em> in vector control programs.