M.C.GUPTA, M.K.MAHLA, M.L.OJHA AND V.P.SAINI

In the present investigation, the efficacy of deltamethrin (butox) was assessed for the control of aquatic beetles. For this purpose, bioassay studies were conducted in 28 l. of static water holdings using six concentrations (0,300,400,500,600,700 &800 ml/ha m.) of deltamethrin. The LC50 values of butox ranged from 268.54 to 381.89, whereas, the 100% beetle toll rate was noticed within 24 hrs when exposed to 500 ml /ha concentration. Further, the second order polynomial regression analysis for deltamethrin concentration v/s beetles tool rate showed that a dose of 485 ml/ha m. is most effective for the control of beetles in fish nursery ponds.