Trema micrantha extract for sustainable spider mite management

Abstract

Given the increasing demand for sustainable alternatives to synthetic acaricides, this study evaluated the acaricidal activity of aqueous leaf extracts of Trema micrantha Blume (Cannabaceae) against adult females of Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) under controlled laboratory conditions. Extracts prepared from dried and powdered leaves were tested at 2.0, 2.7, 3.6, 4.9, 6.6, and 9.0 g/100 mL, using distilled water plus Tween ® 80 as the control treatment. Mortality was recorded over 72 h in BOD-type climate chambers at 25 ± 1 °C and 70 ± 2% relative humidity. The extract caused concentration-dependent mortality, with estimated LC₅₀ and LC₉₀ values of 3.16 and 10.99 g/100 mL, respectively. These results demonstrate that aqueous extracts of T. micrantha have promising acaricidal activity against adult females of T. urticae and may represent a potential botanical tool for integrated mite management. Further studies are needed to evaluate additional developmental stages, sublethal effects, non-target safety, formulation stability, and field performance.