Screening of Some Medicinal and Aromatic Plant Extracts for Their Insecticidal Efficacies

Abstract

Increasing concerns about persistence and environmental impact of synthetic pesticide residues require development of biodegradable and environmentally safe alternatives. The potential of using extracts of some medicinal and aromatic plants as alternative to synthetic insecticides for controlling the sunn pest, Eurygaster maura L. (Heteroptera: Scutellaridae), were explored in this study. Methanol extracts of Melissa officinalis L. (Lamiaceae), Rosmarinus officinalis L. (Lamiaceae), Syzygium aromaticum (L.) (Myrtaceae) ve Origanum vulgare L. (Lamiaceae) were tested against adults of the sunn pest, E. maura under laboratory conditions using topical application method. The effects of five concentrations of plant extracts 5, 10, 20,30 and 40% were studied. The results showed that extracts from O. vulgare and S. aromaticum exhibited the best insecticidal activities (LC₅₀ 13.43% and LC₅₀ %15.94%, respectively), followed by M. officinalis extract (LC₅₀ 19.28%). Toxicity of R. officinalis extract were low. There were no phytotoxicity on plants of plant extract treatment on two different wheat cultivars. These results suggest the presence of actives toxic substances acting topical application (except R. officinalis). The methanol extracts were used as the tested materials in this study, however further study is warranted to isolate and purify the most active compounds.