Toxicity of three plant leaf extracts against larvae and pupae of melon fruit fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae)

Abstract

Methanol extractives of leaves of three selected plants Azadirachta indica A. Juss., Persicaria hydropiper (Linn.) Spach and Vitex negundo Linn. were subjected to larvicidal and pupicidal test against the melon fruit fly, Bactrocera cucurbitae (Coq.) (Diptera: Tephritidae). In larvicidal test, offered the highest and lowest mortality has been calculated as 1.161 and 0.758mg cm-2 for A. indica; 0.853 and 0.275mg cm-2 for P. hydropiper; 2.213 and 0.732mg cm-2 for V. negundo after 6 hours and 24 hours of exposure respectively. In case of pupicidal test against melon fly, the highest and lowest activity has been observed for the extract of A. indica by LD50 0.26mg cm-2 and the extracts of P. hydropiper by LD50 8.70mg cm-2 respectively. Against B. cucurbitae, the pupicidal potentiality of leaf extractives of these three plants can be sequenced in a descending order as A. indica > V. negundo > P. hydropiper.