Folivory on Ipomoea murucoides Roem & Schult exerts metabolic changes related to insecticidal activity against Fall armyworm, Spodoptera frugiperda (Walker)

We studied the effects of 4-levels of leaves herbivory (without herbivory, herbivory < 20 %, herbivory > 20 %) and mechanically damaged leaves of Ipomoea murucoides Roem. & Schult. We prepared the Hexane, Dichloromethane and Methanol extracts from leaves of these 4-groups and added to meridic diet given to Fall armyworm, [Spodoptera frugiperda Walker (Lepidoptera: Noctuidae)] larvae. These extracts chemical composition was analyzed using liquid chromatography coupled to mass spectrometry. The extracts were grouped according to the solvent polarity, however, within each solvent, herbivory treatments were different. The diet containing hexane extract of leaves with herbivory > 20 % and herbivory < 20 % caused maximum mortality (84 % and 68 %, respectively) of S. frugiperda larvae. This study showed that mortality of S. frugiperda larvae depended on the metabolic chemical compounds variations in the extracts of I. murucoides.