Evaluation of residual effects of lambdacyhalothrin WP10 in different surfaces against Anopheles stephensi, in a malarious area, southern Iran

Malaria is major vector-borne diseases in southern Iran. The main activity of vector control is indoor residual spraying using pyrethrpids. The study was conducted to evaluate the biological assays of lambdacyhalothrin WP10 at different surfaces of wall.  The persistency of lambdacyhalothrin WP10 at 25 mg/m2 was studied on different local surfaces of rooms such as  plaster and mud surfaces (sorbent) as well as wooden and thatch roofs (as non-sorbent). Contact bioassays were carried out using world health organization (WHO) standard cones and lab-bred sugar-fed, 48-72 h old females of Anopheles stephensi  (Iranshahr strain). In contact bioassays was carried out on sprayed surfaces for 150 days. Contact bioassay on surfaces treated with lambdacyhalothrin WP10 on sorbent surfaces caused 34 to 100% mortality and 76.32 to 100% on non-sorbent surfaces during 120 days evaluation period and the persistency of lambdacyhalothrin WP10 at 25 mg/m2 was estimated about 2.5 months. Fumigant tests of lambdacyhalothrin WP10 revealed 50 to 93.83% mortality with one month persistency.   Key words: Lambdacyhalothrin, residual effects, fumigant efficacy, Anopheles stephensi, malaria, Iran.