Laboratory induced bifenthrin resistance selection in Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae): Stability, cross-resistance, dominance and effects on biological fitness

Abstract

The dusky cotton bug, Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae) is a serious pest of cotton and damages cotton seed by reducing the oil content. In Pakistan, O. hyalinipennis is managed by using various insecticides and has developed resistance to several insecticides. In this study, O. hyalinipennis was selected with bifenthrin for 12 generations (G1 to G12) and developed a 55.64-fold resistance when compared with an unselected population (Unsel Pop). Bifenthrin resistance declined from 55.64 to 24.93-fold when selected population was removed from bifenthrin selection pressure for four generations (G13 to G16). Bifenthrin selected (Bifen-Sel) population showed a very low cross-resistance to profenofos (2.82-fold), deltamethrin (2.35-fold) and acetamiprid (2.21-fold) when compared with a field population (Field Pop). The bifenthrin resistance was incomplelety dominanat and autosomal. The relative fitness (Rf) of Bifen-Sel population was 0.58 along with significant decreases in average nymphal survival, fecundity, egg hatchability, intrinsic rate of population increase (rm), net reproductive rate (Ro) and biotic potential (Bp). The Rf of Cross1 and Cross2 was 1.07 and 1.22, respectively. The high fitness costs, instable resistance and a very low cross-resistance with other insecticides might be useful in slowing down the evolution of bifenthrin resistance by implementing an insecticide rotation plan.