Abstract
Oviposition byPieris rapae butterflies was deterred by spraying the plant secondary compounds coumarin and rutin on cabbage plants in greenhouse choice tests. In no-choice tests ranging from 5 min to 24 hr, acceptance of rutin-treated plants for oviposition increased with trial duration. Both coumarin and rutin deterred oviposition primarily by affecting prealighting rather than postalighting behavior, indicating that deterrence was mediated by noncontact cues.