Cultivar-specific responses of tomato essential oils to tomato red spider mite (Tetranychus evansi): Implications for pest management

Background: The tomato (Solanum lycopersicum L.) is a widely cultivated and nutritionally valuable plant species, known for its culinary and health benefits. However, tomato crops are susceptible to various pests, including the tomato red spider mite (Tetranychus evansi), which can cause substantial yield losses. Essential oils from plants have shown potential as natural alternatives for pest management. Methods: This study investigated the interaction between essential oils from seven different tomato accessions namely; 1 (money maker), 13 (marglobe), 51 (PI 134417), 162 (JKUAT 22/202183), 182 (JKUAT 19), 428 (LA 2185) and 460 (LO 3279) and T. evansi. The aim was to understand the role of essential oils in shaping mite behavior. Essential oils were extracted from these diverse tomato accessions using steam distillation. The response of spider mites to these essential oils was assessed using Y-tube olfactometer and glass slide bioassays. Gas chromatography/mass spectrometry was used to analyze the composition of volatile compounds released by the essential oils. Results: Spider mite responses to different concentrations of essential oils were not significantly different among accessions. However, specific accessions, such as 51 and 428, elicited negative responses across concentrations. Analysis of volatile compounds revealed qualitative and quantitative variations in essential oil composition among accessions. Compounds like 2-tridecanone, 2-undecanone, β-caryophyllene, and α-humulene exhibited distinct abundance patterns across accessions. Conclusions: The study provides insights into the complex interaction between tomato essential oils and spider mite behavior. While concentrations of essential oils did not strongly influence mite responses, the unique composition of essential oils in different accessions played a crucial role. These findings suggest the potential for selective breeding of tomato varieties with specific essential oil profiles to enhance resistance to spider mites. The research contributes to our understanding of natural pest management strategies and underscores the importance of phytochemical diversity in shaping arthropod behavior.