The tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), first reported in Saudi Arabia in 2010, is one of the most destructive tomato pests worldwide and has developed resistance to many conventional synthetic insecticides. This study evaluated the larvicidal activity of crude extracts from fifteen wild plant species native to Saudi Arabia as sustainable alternatives within integrated pest management (IPM) programs. Fifteen plant extracts were tested at concentrations of 2–8 g L−1 over a five-day exposure period. All extracts showed significant, dose- and time-dependent larval mortality. Prosopis juliflora exhibited the highest efficacy, causing 100% mortality at 8 g L−1, followed by Echinops spinosissimus, Anvillea garcinii, Teucrium baccatus, and Artemisia monosperma, each resulting in more than 80% mortality. Probit analysis indicated comparatively low LC50 and LC90 values for P. juliflora, E. spinosissimus, and A. garcinii. Residual bioassays confirmed the prolonged activity of P. juliflora, while solvent fractionation revealed higher toxicity in non-polar fractions. These findings highlight the potential of selected wild plant species as promising botanical insecticide sources. Further studies on formulation development, non-target organism safety, and field validation are recommended before their integration into IPM programs targeting T. absoluta.
Alhewairini et al. (Wed,) studied this question.