2001 Volume 36 Issue 1 Pages 137-141
Three populations of the western flower thrips, Flankliniella occidentalis (Pergande), were collected from commercial greenhouses (strawberry, rose and gerbera) in Wakayama Prefecture, Japan. Four females were transferred onto a kidney bean leaf, Phaseorus vulgaris L., floated on 0.5% agar gel in a plastic petri dish. The petri dish, which contained 40–80 larvae 2 to 3 days after hatching, was sprayed with 6 ml of insecticides through a spraying tower. Of the organophosphates, dichlorvos, sulprofos, profenofos, prothiofos, malathion, chlorpyrifos-methyl, chlorfenvinphos, fenthion and phenthoate were toxic with more than 90% of corrected mortality. Most carbamates except for methomyl and pyrethroids were less toxic. Of the IGRs, lufenuron, chlorfluazuron and flufenoxuron were effective. Chlorphenapir and spinosad achieved 100% mortality. There was no remarkable difference in sensitivity to the insecticides among the populations except for acrinathrin. The Kishigawa and the Inami populations collected from rose and gerbera, respectively, were more tolerant to acrinathrin than the Iwade population collected from strawberry.