TY - JOUR

T1 - Optimizing western flower thrips management on French beans by combined use of beneficials and imidacloprid

AU - Nyasani, Johnson O.

AU - Subramanian, Sevgan

AU - Poehling, Hans Michael

AU - Maniania, Nguya K.

AU - Ekesi, Sunday

AU - Meyhöfer, Rainer

N1 - Funding information: This study was funded by the BMZ (Federal Ministry for Economic Cooperation and Development, Germany) through GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit) (Project No.07.7860.5-001.00). We thank the Centre Director, KALRO-Embu, Kenya for allowing us to carry out the studies at the Centre. We thank the icipe, Nairobi, Kenya for providing the laboratory facilities and facilitating transport to the study site during the data collection phase. We are grateful to the Thrips IPM staff for their technical assistance. This study was funded by the BMZ(Bundesministerium f?r Wirtschaftliche Zusammenarbeit und Entwicklung) (Federal Ministry for Economic Cooperation and Development, Germany) through GIZ (Deutsche Gesellschaft f?r Internationale Zusammenarbeit) (Project No.07.7860.5-001.00). We thank the Centre Director, KALRO-Embu, Kenya for allowing us to carry out the studies at the Centre. We thank the icipe, Nairobi, Kenya for providing the laboratory facilities and facilitating transport to the study site during the data collection phase. We are grateful to the Thrips IPM staff for their technical assistance.

PY - 2015/3

Y1 - 2015/3

N2 - 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.

AB - 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.

KW - Amblyseius

KW - Benefit-cost ratio

KW - Entomopathogenic fungus

KW - Frankliniella occidentalis

KW - Neonicotinoid

KW - Phaseolus vulgaris

KW - Predatory mite

UR - http://www.scopus.com/inward/record.url?scp=84982671676&partnerID=8YFLogxK

U2 - 10.3390/insects6010279

DO - 10.3390/insects6010279

M3 - Article

AN - SCOPUS:84982671676

VL - 6

SP - 279

EP - 296

JO - Insects

JF - Insects

IS - 1

ER -