Insecticidal susceptibility of Western flower thrips, Frankliniella occidentalis, was investigated under laboratory and greenhouse conditions using commercial insecticides at their recommended concentrations. Neonicotinoid insecticides, especially acetamiprid SP, clothianidin SC, imidacloprid WP and thiacloprid WG were not toxic to F. occidentalis collected from horticultural crops. Excepting the insecticide of spinosin or pyrrole class, there was a little class of insecticides for the effective control of F. occidentalis in horticultural crop areas. Considering all the results in this study, spinosin insecticides including over 4 and 10% of spinetoram and spinosad, and pyrrole insecticide including over 5% of chlorfenapyr should be recommended for the effective control of F. occidentalis

• Young-Su Lee(Department of Agricultural Biology, Gyeonggi-do Agricultural Research and Extension Services)
• Hyun-Ju Lee(Department of Agricultural Biology, Gyeonggi-do Agricultural Research and Extension Services)
• Soon-Sung Hong(Department of Agricultural Biology, Gyeonggi-do Agricultural Research and Extension Services)
• Chang-Sung Kang(Department of Agricultural Biology, Gyeonggi-do Agricultural Research and Extension Services)