Evaluation of residual effect of deltamethrin 5% against Anopheles stephensi in Iranshahr District of Southeastern Iran

Abstract:
An attempt was made to evaluate the residual effect of deltamethrin 5% WP at recommended dosage of 25 a.i.mg/m2 on different local surfaces such as mud, plaster, cement, tile and brick walls as well as wooden and thatch roofs in a malarious area, Sistan & Baluchistan provinces, in southeastern Iran. Contact bioassay tests were carried out using WHO standard method against 2-3 day sugar fed, a lab-bred strain of Anopheles stephensi (Iranshahr strain). The result of bioassay tests showed 79.1%-94.0% mortality on sorbent surfaces and 64.8% 81.3% on non-sorbent surfaces respectively. Due to irritation of deltamethrin, particularly during the first week of bio-assay test, mortality did not reach 100%. Based on the result of this study, it could be concluded that deltamethrin WP 5% is an insecticide with a residual effect activity of about 2-3 months.