Insights on solanaceous resistance against tomato leafminer (Tuta absoluta), with emphasis on chemical compounds useful in integrated pest management

For integrated pest management (IPM) and organic farming, breeding resistant varieties is one of the most eco-friendly approaches, that goes along botanicals and other different cultural practices, as the use of companion plants. Among the many pest species that invaded the whole world in the last decades, one of the most frightening is the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a devastating pest of cultivated tomato worldwide. Tomato is one of the most important agricultural commodities, including the main mean of subsistence in many countries from Africa and middle East. As chemical pesticides failed to control de pest spread and led to many reports of resistant populations, alternative methods for tomato leafminer management must be quickly developed. Many of such alternatives count on a wide range of chemical compounds. The chemical compounds most often responsible for “constitutive resistance”, synthetized by tomato are methyl-ketones (2-tridecanone), sesquiterpenes (zingiberene), and acyl sugars (acylglucose and acylsucrose) while the chemical compounds produced by other plants, used as isolated substances or mixtures, which have antifeedant, growth inhibiting, repellent, and insecticide effects, are azadirachtin, carvacrol, cinnamaldehyde, citronellal, eugenol, linalool, nicotine, pyrethrin, rotenone, thujone, thymol, α-terpineol, 1.8-cineol, etc. Many of them are already commercially available but their efficacy and use differ widely. Therefore, a deeper understanding of the resistance mechanism of solanaceous species related to chemical compounds and substances important for IPM plans developed against T. absoluta is required by the breeding programs.