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

Abstract

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 ofcompanion plants. Among the many pest species that invaded the whole world in the last decades, one of themost frightening is the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a devastatingpest of cultivated tomato worldwide. Tomato is one of the most important agricultural commodities, includingthe main mean of subsistence in many countries from Africa and middle East. As chemical pesticides failed tocontrol de pest spread and led to many reports of resistant populations, alternative methods for tomatoleafminer management must be quickly developed. Many of such alternatives count on a wide range of chemicalcompounds. The chemical compounds most often responsible for “constitutive resistance”, synthetized bytomato are methyl-ketones (2-tridecanone), sesquiterpenes (zingiberene), and acyl sugars (acylglucose andacylsucrose) 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 andsubstances important for IPM plans developed against T. absoluta is required by the breeding programs