Insecticidal activity from leaves and sesquiterpene lactones of Tithonia diversifolia (Helms.) A. Gray (Asteraceae) on Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract Plant extracts can be used as an alternative to synthetic insecticides for the control of insect pests. This work aimed to evaluate the insecticidal effect of the ethyl acetate fractions and sesquiterpene lactones from Tithonia diversifolia (Asteraceae) leaf extract against the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). As a result, we found that the fraction A (20% methanol (MeOH)) at 100 ppm reduced pupal weight by 12.2% compared to the control. Fractions B (40% MeOH) and C (60% MeOH) at 100 ppm increased the duration of the larval period by 1.87 and 2.03 days, respectively. The sesquiterpene lactones tagitinin A (1), tagitinin C (2) and 1β-methoxydiversifolin (3) at 100, 50 and 10 ppm affected the larval development with reduction of the larval period and pupal weight. Neither the fractions nor the pure compounds interfered with the duration of the pupal phase, nor did they cause larval or pupal mortality.