Development of resistance in red palm weevil to three insecticides and phosphine (PH3)

Abstract: In this study insecticide resistance in field populations of red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) from two different areas across Punjab Province (Pakistan) were determined. Among the tested insecticides, elevated levels of resistance were recorded for cypermethrin, deltamethrin and PH3 in RPW. Highest resistance ratios (RRs) were documented for PH3 63.09 and 68.76-fold for cypermethrin 39.41 and 69.49-fold and for deltamethrin 34.52 and 53.81-fold. All populations exhibited high levels of resistance to tested chemicals. This study suggests that lambda-cyhalothrin can be effectively used against this voracious insect pest.