Assessing the bioefficacy of botanical pesticides derived from ethanolic leaf extract of eight invasive plant species against the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae)

In this study, eight invasive plant species were processed into botanical pesticides, and their bioefficacy was tested against the two-spotted spider mite, Tetranychus urticae. The evaluated botanical pesticides showed high toxicity against adult females of T. urticae, where the mortality ranged from 39.5-99.5% in the treatment groups, while the mortality was 0.5% in the control. Moreover, the oviposition deterrence activity of the botanical pesticides was reflected by the lower number of eggs laid in the treatment groups (9.1-255.5 eggs) compared to the control (504.8 eggs). The ovicidal activity bioassay revealed that the hatchability of eggs following the application of botanical pesticides was reduced to 63.5-95.5%, while the hatchability was 98.8% in the control. However, the ethanolic leaf extract of Mimosa pudica seemed to be the most efficacious botanical pesticide in all parameters observed since it showed high efficacy even when applied at a concentration of 7.5 g/L instead of 10 g/L. Through gas chromatography-mass spectrometry (GC/MS) analysis, 15 phytoconstituents that might be responsible for the anti-mite features were identified. The botanical pesticides used in this study have the potential to be used as environmentally friendly measures to manage T. urticae particularly in organic farming.