Effects of the Mint Monoterpene Pulegone on Spodoptera eridania (Lepidoptera: Noctuidae)

Last-instar southern armyworm, Spodoptera eridania (Cramer), larvae fed on diets containing up to 0.1% of pulegone developed into reproducing adults. A 0.2% pulegone-containing diet retarded development and inhibited reproduction. Last-instar larvae accepted a single small meal loaded with up to 4% pulegone, which was acutely toxic to them only at concentrations far exceeding those occurring naturally and those rejected in feeding tests. Pulegone is an effective defensive chemical due, to its interference with feeding behavior, development, and reproduction, not because of its acute toxicity.