Elucidating the Fitness of a Dead-End Trap Crop Strategy against the Tomato Fruitworm, Helicoverpa armigera

Solanum viarum has been proposed as a potential dead-end trap crop for the management of Helicoverpa armigera because of its unsuitability for larval growth and survival despite being overwhelmingly preferred for oviposition. This study delved into the different S. viarum accessions for ovipositional preference and non-suitability for larval growth and survival of H. armigera. Besides, foliage trichomes, acylsugars, and phenolic content of S. viarum plants were assessed and compared with tomato. Since there is no significant variation in the ovipositional preference and larval performance of H. armigera, our result revealed that all those evaluated accessions of S. viarum have the potential to be used as a dead-end trap crop for the management of H. armigera. However, significant variation among the S. viarum accessions in terms of H. armigera oviposition was also evident in a no-choice experiment. Because of high-density glandular trichomes, acylsugars, and phenolic content, S. viarum significantly impaired H. armigera larval growth and survival compared to the tomato. Hence, our study elucidated that the S. viarum plant fits with the criteria for dead-end trap crop, and has the potential as a dead-end trap crop for the H. armigera, which needs to be tested under large, open-field conditions.