Abstract

Background: Flavonoids, a class of plant phenolic compounds, act as plant defense chemicals. Chrysoeriol is a naturally occurring flavonoid produced by Melientha suavis Pierre. The goal of this study was to investigate the insecticidal potential and mode of action of chrysoeriol isolated from M. suavis against Spodoptera litura (Fabricius). Results: The effects of chrysoeriol on second-instar S. litura larvae were determined by topical application. Chrysoeriol was highly toxic to S. litura (24- and 48-h LD<inf>50</inf> values of ~ 6.99 and 6.51 µg/larva, respectively). Moreover, mode-of-action experiments demonstrated that this compound significantly decreased the activities of both detoxification-related enzymes [carboxylesterases (CarE) and glutathione S-transferase (GST)] and neurological enzymes (acetylcholinesterase). Conclusions: These results indicate that chrysoeriol isolated from M. suavis could be used as a potential agent with activity against S. litura. However, it is necessary to determine the potential side effects on nontarget species for the further development of these novel insecticides. Graphical Abstract: [Figure not available: see fulltext.]