Bioefficacy of organophosphates, pyrethroids and new chemistry insecticides against a field population of dusky cotton bug, Oxycarenus spp. (Hemiptera: Oxycarenidae) in Bt cotton ecosystem

The dusky cotton bug is a widespread polyphagus pest of economic importance. Both nymphs and adults feed on immature seeds and cause quantitative and qualitative loss in cotton. As information on its susceptibility to insecticides under field conditions was scarce; susceptibility of dusky cotton bug to different pyrethroid, organophosphate and new chemistry insecticides was tested under field conditions at Government Agricultural Farm, Vehari, Pakistan in the year 2012. The experiment was conducted under Randomized Complete Block Design with three replications of each treatment. All the insecticides tested, except deltamethrin 2.5EC proved effective against both adults and nymphs of dusky cotton bug. Triazophos 40EC, Nurelle-D 505EC, Curacron 500EC, Fiprox 5SC, Adder Plus 360EC and mixture of Lancer 2.5EC & triazophos 40EC were significantly effective in reducing dusky cotton bug population 72 hours (23.75-55.85%) and even 168 hours (27.49-54.02%) post treatment under field conditions in Bt cotton ecosystem. These chemical insecticides may be considered to be appropriate for field use against this pest.