Toxicity of imidacloprid to developmental stages of Rhynchophorus ferrugineus (Curculionidae: Coleoptera): Laboratory and field tests

The toxicity of imidacloprid was evaluated against various developmental stages of the red palm weevil (RPW), Rhynchophorus ferrugineus Olivier. Based on topical, oral, and contact toxicity bioassays, imidacloprid was very effective in controlling various stages of the RPW. Mortality increased with exposure time and dose. The qualitative chemical analysis, using the TLC technique, detected the imidacloprid residues in leaf base and gomar parts; while the quantitative analysis, using the UV spectroscopy analysis, confirmed and quantified residues in all plant parts. The imidacloprid-formulated compound gave excellent control, in the semi-field and field experiments, when applied with soil-drench-irrigation. The development of treatment strategies for the inclusion of imidacloprid in RPW integrated management programs would be worth considering.