title: Optimizing Western Flower Thrips Management on French Beans by Combined Use of Beneficials and Imidacloprid.
abstract: Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an important pest of vegetable crops worldwide and has developed resistance to many insecticides. The predatory mites Neoseiulus (=Amblyseius) cucumeris (Oudemans), the entomopathogenic fungus Metarhizium anisopliae (Metsch.), and an insecticide (imidacloprid) were tested for their efficacy to reduce WFT population density and damage to French bean (Phaseolus vulgaris L.) pods under field conditions in two planting periods. Metarhizium anisopliae was applied as a foliar spray weekly at a rate of one litre spray volume per plot while imidacloprid was applied as a soil drench every two weeks at a rate of two litres of a mixture of water and imidacloprid per m². Neoseiulus cucumeris was released every two weeks on plant foliage at a rate of three mites per plant. Single and combined treatment applications reduced WFT population density by at least three times and WFT damage to French bean pods by at least 1.7 times compared with untreated plots. The benefit-cost ratios in management of WFT were profitable with highest returns realized on imidacloprid treated plots. The results indicate that M. anisopliae, N. cucumeris, and imidacloprid have the potential for use in developing an integrated pest management program against WFT on French beans.
authors.affiliation: Kenya Agricultural and Livestock Research Organization, Embu Research Centre, P O Box 27-60100 Embu, Kenya. jnyasani@icipe.org.|Institute of Horticultural Production Systems, Section Phytomedicine, Leibniz Universität Hannover, Germany, Herrenhäuser Strasse 2, Hannover, 30419, Germany. jnyasani@icipe.org.|International Centre of Insect Physiology and Ecology, P O Box 30772-00100 Nairobi, Kenya. jnyasani@icipe.org.
authors.forename: Johnson O
authors.initials: JO
authors.lastname: Nyasani
authors.affiliation: International Centre of Insect Physiology and Ecology, P O Box 30772-00100 Nairobi, Kenya. ssubramania@icipe.org.
authors.forename: Sevgan
authors.initials: S
authors.lastname: Subramanian
authors.affiliation: Institute of Horticultural Production Systems, Section Phytomedicine, Leibniz Universität Hannover, Germany, Herrenhäuser Strasse 2, Hannover, 30419, Germany. poehling@ipp.uni-hannover.de.
authors.forename: Hans-Michael
authors.initials: HM
authors.lastname: Poehling
authors.affiliation: International Centre of Insect Physiology and Ecology, P O Box 30772-00100 Nairobi, Kenya. nmaniania@icipe.org.
authors.forename: Nguya K
authors.initials: NK
authors.lastname: Maniania
authors.affiliation: International Centre of Insect Physiology and Ecology, P O Box 30772-00100 Nairobi, Kenya. sekesi@icipe.org.
authors.forename: Sunday
authors.initials: S
authors.lastname: Ekesi
authors.affiliation: Institute of Horticultural Production Systems, Section Phytomedicine, Leibniz Universität Hannover, Germany, Herrenhäuser Strasse 2, Hannover, 30419, Germany. meyhoefer@ipp.uni-hannover.de.
authors.forename: Rainer
authors.initials: R
authors.lastname: Meyhöfer
keywords: Amblyseius; Frankliniella occidentalis; Phaseolus vulgaris; benefit-cost ratio; entomopathogenic fungus; neonicotinoid; predatory mite