Efficacy of Plinazolin and Selected Conventional Insecticides for Control of Pepper Weevil ( Anthonomus eugenii ) Adults: A Laboratory Bioassay

Abstract Pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is one of the most economically troublesome pests of pepper production in the southern and south eastern USA. Management of this pest is challenging due to the internal larvae feeding habitat and development, limiting exposure to synthetic insecticides and reducing control efficacy. The effectiveness of available insecticides is further constrained by their non-target effects and the potential for resistance development. Here, we investigated the efficacy of the novel insecticide plinazolin (ISM-555) and selected conventional insecticides against adult pepper weevil under laboratory conditions. Adult mortality and incapacitation were assessed following insecticide exposure. Plinazolin and oxamyl (Vydate® C-LV) caused the highest adult mortality, while thiamethoxam (Actara®) also exhibited significant mortality compared with the untreated control. The results demonstrate the potential of plinazolin as an effective tool for pepper weevil management and provide baseline susceptibility data to facilitate monitoring of pepper weevil populations. Incorporating insecticides with different modes of action into rotation programs may improve control efficacy, and reduce the risk of resistance via integrated pest management (IPM) strategies for pepper weevil. Information © The Authors 2026