Document Type : Original Article
Authors
Department of Plant Protection, College of Food Science and Agriculture, King Saud University, P. O. Box 2460 Riyadh 1 1451, Saudi Arabia
10.21608/jpces.2005.459540
Abstract
Three formulated pyrethroid-based insecticides, Scidco-alpha, Scidcodelta and Restagaurd and their five technical components cypermethrin, deltamethrin, tetramethrin, s-bioallethrin and d-phenothrin were evaluated for their effect against the 4ff instar larvae of a laboratory and two field strains of Culex pipiens, collected from two Ications in Riyadh, Irqa (location A) and El nafl (location B). In addition, two formulated organophosphorus-pyrethroid mixed insecticides (Fenitrothion 55/5 and Combi 25/10) and their technical components (fenitrothion, tetramethrin and fenvalerate) were tested against the above-mentioned strains. The results showed the appearance of tolerance or resistance of field strains to most of these insecticides. In location A the resistance ratios were 7.44, 0.92, 57.7, 2.75, 10, 4.68, 2.3, >29.9, 1.45, 1.19, 2 and 4.01 for Scidco-alpha, Scidco-delta, Rßtagaurd, a- cypermethrin, deltamethrin, tetramethrin, s-bioallethrin, d-phenothrin, Fenitrothion 55/5, Combi 25/10, fenitrothion and fenvalerate, respectively, while in location B the resistance ratios were 7.67, 1.75, 67.8, 4.5, 8.46, 3.14, 2.55, > 24.9, 2.18, 13.9, 4.1 and 4.5 for the above mentioned insecticides, respectively.
Keywords
)
