Susceptibility Status of Bemisia tabaci Biotypes to Pyrethroid Insecticides in North-Eastern Nigeria

A study was conducted to assess the effect of treatments with the recommended application rate of α-Cypermethrin, Permethrin, Allethrin, Tetramethrin, Cyhalothrin and Deltamethrin pesticides on Bemisia tabaci biotypes. Two localities each were selected from three States of North-eastern Nigeria for sample collections and determination of susceptibility to the insecticides. The localities include Toro and Wuro wasse in Bauchi State, College of Agric farm center (COAG) and Tudun wada in Borno State, Dadin kowa and Kwadon in Gombe State. The insecticides were applied against adult B. tabaci using a leaf-dip bioassay. Insect population that survived any of the insecticides after 24 hours post exposures were considered resistance to the insecticide and their biotypes were determined using Polymerase Chain Reaction (PCR). Overall mean mortality response was 88.89%, 91.27%, 88.09%, 96.83%, 93.65%, and 96.05 for α-Cypermethrin, Permethrin, Allethrin, Tetramethrin, Cyhallothrin and Deltamethrin respectively and all were significantly different from control (P<0.05). Populations from Kwadon showed high resistant factor to α-Cypermethrin, Tetramethrin and Cyahallothrin (RF = 221.99, 128.05 and 98.8-folds respectively). All populations displayed significant resistance to Allethrin (RF ranging from7.01-fold in Tudun wada to 78.93-fold in Kwadon. Tetramethrin resistant was followed by Dadin kowa and Tudun wada (RF = 13.43 and 13.33) respectively and Cyahallothrin resistant was followed by population from Dadin kowa (RF = 82.94-folds) while Deltamethrin resistant was found to be insignificant between almost all locations. Biotype B exhibited higher resistance for all the evaluated insecticides compared to Q in all locations