Three stored-product phycitid moths were exposed 2 hours daily for 6 days to atmospheres containing about 96% CO2, Egg hatch was completely eliminated in the Mediterranean flour moth,Anagasta kuehniella(Zeller), and was less than 2% in the almond moth,Cadra cautella(Walker). Carbon dioxide was slightly less effective in preventing egg hatch in the Indian meal moth,Plodia interpunctella(Hübner). A large reduction in oviposition occurred in all 3 species.