Pubblicazioni

Combining host plant resistance and natural enemies is a promising approach to replace chemical insecticides for the control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), an invasive pest threatening tomato production worldwide. However, morphological resistance traits, secondary metabolites, and plant volatiles of tomato can also affect natural enemies and thus the overall level of pest control. In this study, we aim at characterizing the interaction between T. absoluta – tomato varieties – and natural enemies. Therefore, we performed a resistance assessment of 19 tomato varieties including 16 domesticated ones, one wild-domesticated and two wild tomatos against T. absoluta. Tomato varieties affected the oviposition potency, larval mining time, larval development time, leaf area damaged, pupal weight and the emergence of adult T. absoluta. Notably, the wild tomatoes Solanum arcanum and S. neorickii and the domesticated tomato Corona F1 caused detrimental effects on T. absoluta. Trichome density did not influence female oviposition but extended larval establishment time on leaflets. Subsequently, six varieties (four domesticated ones and the wild tomatoes S. arcanum and S. neorickii) that strongly differ in their level of resistance were selected to assess the performance of the egg parasitoid Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) and the larval parasitoid Necremnus tutae (Reuter) (Hymenoptera: Eulophidae). Domesticated plants and the wild tomato S. neorickii showing lower densities of glandular trichomes had no effect on parasitoid efficacy, in contrast to the wild tomato S. arcanum exhibiting the highest density of glandular trichomes and negatively impacted the performance of both parasitoid species. Our findings demonstrate the complex interaction between host plants differing in resistant traits and natural enemies. The impact of plant resistance on these natural enemies as well as implications for the sustainable management of T. absoluta are discussed.