Effect of Taxus Foliage and Extract on the Toxicity of Some Pyrethroid Insecticides to Adult Black Vine Weevil (Coleoptera: Curculionidae)

The pyrethroid insecticides fenvalerate, permethrin, and fluvalinate were more toxic to adult black vine weevil, Otiorhynchus sulcatus (F.), on yew, Taxus media Rehder, foliage rather than on leaves of strawberry, Fragaria × ananassa Duchesne, or cranberry, Vaccinium macrocarpon Ait. Feeding weevils untreated yew foliage or an ethanolic extract of yew needles for 24 h before placing them on fenvalerate-treated strawberry leaves greatly increased knockdown. Host plant species must be considered when pyrethroids are used for control of adult black vine weevil.