author(s)
Bidisha Paul, Snigdha Samanta, Koushik Sen, Arpana Manger and Arunava Samanta

abstract
Field experiments were conducted on two rice varieties, IET 4786 and Satabdhi to study the bioefficacy of the formulations of fipronil 5% SC and acetamiprid 20% SP at three different doses (20, 50 and 100 gm a.i./ha; and 10, 20 and 40 gm a.i./ha, respectively) against different insect pest complex during 2014 and 2015. Results of the experiment revealed that, highest reduction in dead hearts/ white ears was recorded in fipronil 5% SC @ 75 gm a.i./ha. Similarly, highest reduction in population of leaf hoppers, plant hoppers, gall midge and whorl maggot and highest yields were recorded in plots treated with fipronil 5% SC @ 75 gm a.i./ha. For Acetamiprid 20% SP, highest reduction in brown plant hopper population and highest yields were recorded in the plots with doses 10 and 20 gm a.i./ha. No phytotoxic symptoms were recorded due to any of the insecticides even at higher than field recommended doses. Both the insecticides did not have any severe depressing effect on the natural enemies in the field when applied at recommended doses.