title: Behavioural responses ofFrankliniella occidentalisPergande larvae to methyl jasmonate andcis-jasmone.
abstract: The larval stages ofFrankliniella occidentalisPergande (Thysanoptera: Thripidae) cause more direct feeding damage to plants than the adults. We, therefore, investigated the behaviour-modifying effects on second instar larvae of two jasmonic acid derivatives. The artificial application of methyl jasmonate andcis-jasmone, both at 1 % concentration, deterred the larvae from settling in a dual choice bean leaf disc assay. We observed a dose-dependent feeding deterrence of both jasmonates and calculated the concentration required to reduce the feeding damage by 50 % relative to the control treatment (FDC50) for each jasmonate. The feeding damage was reduced by the application ofcis-jasmone at 1 % concentration, but not by the jasmonates at the respective FDC50in no-choice leaf disc bioassays. However, significantly more larvae left jasmonate-treated whole potted bean plants by migrating to the soil compared with control plants. Our results may be exploited extending behavioural manipulation by using plant compounds in thrips control programmes to the full lifecycle of the pest. Plant compounds could be used in integrated and biological pest management strategies againstF. occidentalisin combination with the application of various above and below ground control measures.
authors.affiliation: Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Egger
authors.affiliation: Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Koschier
keywords: Feeding deterrent; Jasmonates; Leaving behaviour; Second instar; Secondary plant compounds; Thrips