Lambda-cyhalothrin spray as an insectproofing agent for woollen fabrics

Abstract

The effectiveness of synthetic pyrethroid lambda-cyhalothrin at 0.01, 0.025 and 0.05% concentrations as solvent-based sprays was evaluated against the larvae of the tropical case making clothes moth,<i>Tinea translucens </i>Meyrick and the furniture carpet beetle, <i>Anthrenus falvipes </i>LeConte. Lambda-cyhalothrin spray at 0.025 % concentration provided high degree of protection to the wool fabric even after 30 months of the ageing of treated fabric from these two serious wool pests.Lambda-cyhalothrin showed ovicidal action as all eggs, laid on the treated fabric by the moths, were killed. The minimum effective concentration of lambda-cyhalothrin for complete protection of woollen fabric was determined to be 0.005% on wool weight against the larvae of <i>A. flavipes. T. translucens </i>was found more susceptible than A. flavipes to lambda-cyhalothrin. Residue of lambda-cyhalothrin was estimated 25-35% lower than its initial deposits on the fabrics after 30months of its application.