Anti-feedant activity of the polyacetylene,phenylheptatriyne (PHT), from the Asteraceae toEuxoa messoria (Lepidoptera: Noctuidae)

Summary Phenylheptatriyne (PHT), a polyacetylene from various species of Asteraceae reduced feeding and weight gain of larvae of the polyphagous insectEuxoa messoria when incorporated into an artificial diet at concentrations of 10–300 ppm. These results suggest a role as insect antifeedants for the widely distributed polyacetylenes of the Asteraceae.Acknowledgment. This work was supported by NSERC and Agriculture Canada (E.M.R.) We thank Dr R. J. Byers (Agriculture Canada) for eggs ofEuxoa. To whom reprint requests should be addressed.