To establish a simple method for rearing Propylea japonica (Thunberg), we investigated its larval and pupal development and reproduction when offered Ephestia kuehniella Zeller eggs as an alternative diet. Larvae raised on E. kuehniella eggs matured as well as those raised on Acyrthosiphon pisum (Harris), and could be reared at high densities without cannibalism when a sufficient diet was supplied. Although the mean fertility of the adults reared on E. kuehniella eggs was about one-third of that of the adults reared on A. pisum, 63.7–66.5% of the eggs hatched and the larvae matured normally. These results suggest that E. kuehniella eggs are an available alternative diet for the larval and pupal development and reproduction of P. japonica, and should make it possible to rear successive generations. However, to obtain large amounts of larvae at the same developmental stage and to collect eggs efficiently, the larvae should be reared on E. kuehniella eggs and the adults should be reared on aphids such as A. pisum.