Effectiveness of cartap hydrochloride against rice stem borer and leaffolder and its safety to natural enemies

Four field experiments conducted to evaluate the efficacy of cartap hydrochloride @ 1 kg a.i./ha in comparison with check insecticide carbofuran during 1999 (I crop season), 2000 (I crop season) and 2001 (I and II crop seasons) showed that cartap hydrochloride treatment in nursery five days before pulling rice seedlings had reduced incidence of dead hearts (35.6 %) and white ear (28.4 %) caused by yellow steniborer, Scirpophaga incertulas Walker and reduced leaf damage by leaf folder, Cnaphalocrocis medinalis Guenee by 47.7 per cent with increased grain yield in comparison with check insecticide (carbofuran) drenched seedlings. The cartap hydrochloride drenched seedlings supported higher population of natural enemies like spiders (Tetraguatha sp.) while other natural enemies like damselflies (Agriocnemis sp.), green mirid bugs (Cyrtorhinus lividipennis) and larval parasitoids (Stenobracon sp.) were on par with the untreated plots.