Antifeedant and Phagostimulant Activity of Extracts and Pure Compounds from Hymenoxys robusta on Spodoptera exigua (Lepidoptera: Noctuidae) Larvae

In this study, the insecticidal and antifeedant activities of compounds from the leaves of Hymenoxys robusta on Spodoptera exigua, also known as armyworm, are reported. The methanol extract possessed suppressive activity, as well as a high antifeedant activity, suggesting that this extract has toxic effects on larvae. Compounds isolated from the plant show that a derivative of inositol and hymenolides stimulate the feeding, while vermeerin shows a high antifeedant effect. In addition, the methanol extract inhibited oviposition, whereas consumption of the n-hexane extract and hymenolides produced infertile eggs. These findings suggest that compounds extracted from H. robusta have potential for the development of products for pest control.