Tomato plants selected to high levels of zingiberene influence herbivory and fecundity of Diabrotica speciosa

Zingiberene is an allelochemical found in wild Solanum species and plants resulting from crosses between these and S. lycopersicum. This sesquiterpene is known to reduce the performance of pest herbivores. Diabrotica speciosa has been identified as a potential tomato pest in important producing regions in Brazil, causing damage to leaves and fruits. Therefore, in this study, we investigated how zingiberene, found in advanced tomato genotypes, can affect the food preference, oviposition and longevity of South American corn rootworm, D. speciosa. The feeding behavior of adults was evaluated in bioassays with and without choice. Additionally, a damage scale for tomato plants was constructed to estimate consumption levels in each genotype. Longevity data and the number of eggs deposited on leaflets were obtained from females kept in cages and fed with tomato leaves from each genotype individually. High levels of zingiberene affected the host selection behavior for feeding and the number of eggs deposited by D. speciosa, so that high levels of the compound increased mortality and reduced adult oviposition, which implies the first record of the action of this compound on this insect. These results can guide breeding programs to obtain genotypes that express high levels of zingiberene, which will present greater resistance to the insect, reducing insecticide applications.

Summary of the effects of high levels of zingiberene in tomato plants (Solanum spp.) on the biological and behavioral aspects of Diabrotica speciosa (Coleoptera: Chrysomelidae).Ali et., 2019; Rakha et al. 2017; Zeist et al. 2019a, b; Oliveira et al. 2020.