Investigation were conducted to test the insecticidal property of sweet flag rhizome (Acorus calamus L.) formulations with cow dung ash as a carrier against Callasubruchus chinensis L. on pigeonpea in storage during 2006-07 at the Department of Agricultural Entomology, College of Agriculture, Raichur, Karnataka state. The results revealed that the tablet form of sweet flag rhizome powder with cow dung ash as a carrier at 15 and 20 per cent concentration reduced the egg laying with 18.44 eggs/ 10 seeds.  The sweet flag rhizome powder at four per cent concentration reduced the seed damage with 16.33 per cent as against 41.11 per cent in untreated check after 120 days after storage (DAS).  The seed weight loss was also minimum in seeds treated with sweet flag rhizome powder in tablet form at 15 per cent concentration as it recorded 0.98 per cent seed weight loss after 120 days after storage.  The number of adults emerged per 100 g of seeds after 120 days after storage was minimum in seeds treated with sweet flag rhizome powder in tablet form at 15 per cent concentration with 21.88 adults/ 100 g of seeds.