EVALUATIONS OF Moringa oleifera LAM. AS ACARICIDE AGAINST Tetranychus urticae KOCH (Acari: Tetranychidae)

Abstract

The acaricidal, ovicidal, repellent and oviposition deterrence activity of ethanolic leaf extract from Moringa oleifera Lam.were assessed against Tetranychus urticae. The study wasconducted in the laboratory of the Department of Entomology, Hajee Mohammad Danesh Science and Technology University (HSTU),Dinajpur, at 25 ± 1°C, 65 ± 5% RH and 16:8 (L:D) hours. The effects of ethanolic leaf extract from M. oleiferawere assessed at 0.5, 1.0, 2.0, 3.0 and 4.0% concentrations. The findings revealed that all concentrations had acaricidal, ovicidal, repellent, and oviposition deterrent effects on T. urticae. Adult and nymph mortality rates were increased with increasing doses and time (after 24, 48, and 72 hours). The extracts at 4.0% concentration showed the highest mortality of adults (90.0%) and nymphs (94.0%) after 72 h exposure. Mortality was greater in nymphal stage (56.0-94.0%) than in adult females (7.0-90.0%) when treated with different concentrations. Ovicidal activity (after 7 days) results showed that the lowest egg hatchability was (58.0%) at 4.0% concentration with the highest reduction of viable eggs (-41.00). The LD50 values of ethanolic extract for adult females were 3.368, 2.357 and 1.042 at 24, 48 and 72 h, respectively and for nymphs were 0.477, 0.295 and 0.171 at 24, 48 and 72 h, respectively and for eggs it was 8.435 after 7 days. In the repellency test, all concentrations showed repellent effects against T. urticae and the highest repellency (92%) was observed at highest concentration (4.0%). Ovipositional deterrence ranged between 9to30%.The result suggested that ethanolic extract from M. oleifera leaves can be used as a powerful bio-acaricide for the control of T. urticae.