Insecticidal activities of five plant derived chemicals on Thrips tabaci Lindeman

Abstract

Background: Natural compds. originating from plants might be potential alternative pesticide that are not persistent in the environment and are safe to non-target organisms and for use in sustainable agriculture. Methods: Ethanolic exts. (30μl/mL) of Melia azedarach L. (Fruits), Peganum harmala L. (seeds), Calendula officinalis L. (seeds), Ferula assafoetida L. (resin) and Cercis siliquastrum L. (seeds) were applied against 1-2 and 5-6 days of Thrips tabaci Lindeman. All the expts. were conducted by spray test bioassay. Ethanol (95%) was used as a control treatment. Results: All the plant derived chems. were highly toxic against the pre-imago thrips. The mortality percentages of the pest (1-2 day old) after 72 h were more than 66.0% in each of the plant exts. The highest insecticidal activity against the above-mentioned pre-imago thrips was recorded for the F. assafoetida treatment (96.7%). Insecticidal activity was more than 85% in the ethanolic ext. M. azedarach and P. harmala treatments. Moreover, the mortality percentage of the thrips (5-6-day old) after 72 h was more than 80.6% in the ethanolic ext. of F. assafoetida treatment. Conclusions: The plant derived chems. tested in this study may be useful as a insecticide in T. tabaci management programs, although their safety towards humans needs verification. [on SciFinder(R)]