Deterrence of Diamondback Moth (Lepidoptera: Plutellidae) Oviposition by Plant Compounds

Diamondback moth, Plutella xylostella (L.), oviposition was deterred by spraying the plant secondary compounds coumarin and rutin on cabbage plants in laboratory choice tests. Deterrent effects of the compounds were not reduced when females were exposed to treated plants for 48 h. Coumarin was a more potent deterrent in darkness (4.1-fold) than in light (2.3-fold), but rutin's effect was stronger in light (3.2-fold) than in darkness (1.9-fold). Results support the view that diamondback moth oviposition is mediated by several sensory modalities including vision, chemoreception, and mechanoreception.