Effect of sub-lethal doses of beauveria bassiana and nitenpyram on the development of red palm weevil, rhynchophorus ferrugineus (olivier)

Abstract

Red palm weevil Rhynchophorus ferrugineus (RPW) is a very serious pest of oil palms, coconut palms and date palms in many parts of the world. The present study was carried out to study RPW biology and development under laboratory conditions and survival against sub-lethal doses of B. bassiana and biorational insecticide (Nitenpyram). Sugarcane sets as alternate to date palm stem were successfully used as diet for rearing RPW. Combination of entomopathogenic fungus (Bb) and Nitenpyram (Nit) were found more lethal to survival of RPW. A reduction in pupation and adult emergence was recorded in the combined treatments. Moreover, decrease in weight gain, frass production and cumulative gain in size was found when larvae were treated with integrated effect of Bb and Nit. Depending on the lethal of treatment, development duration of RPW was disturbed. Integration of Bb and Nit delays the development and diet uptake in RPW which can be used for agent of control for this cryptic insect.