Chemical composition and bioactivity of Lantana camara L. essential oils from diverse climatic zones of Kenya against leaf miner (Tuta absoluta Meyrick)

In recent years, essential oils (EOs) as alternatives to synthetic pesticides in managing pests have been assessed. The use of bioinsecticide in pest management is encouraged in agroecology for a sustainable agricultural system. Essential oils of Lantana camara L. leaves from different climatic zones of Kenya were extracted by steam distillation and analyzed through GC-MS to identify the compounds. The contact toxicity and repellent activity of EOs against the invasive tomato pest, Tuta absoluta, were tested. The toxicological assays were performed following the leaf-dip bioassay protocol, while the repellency activity was performed using the repellent response method for phytophagous pests and the data analyzed using the ANOVA test. It was found that L. camara EO has a good insecticidal activity with higher mortality (89%) on the 2nd instar larvae with a higher dosage (0.01 µl/µl). The repellence test also showed a higher average repellence (93.44%) effect with a higher dosage (0.01 µl/µl) of the EOs. According to these results, the EO of L. camara may well be a sustainable, eco-friendly alternative for synthetic insecticide in the T. absoluta management program. Key words: Bioinsecticide; essential oil, integrated pest management, invasive species, secondary metabolites.