The larvae of the three common species of Ephestia, E. kühniella, Zell., E. elutella, Hb., and E. cautella, Wik. , are serious pests of stored food products, particularly cereals, dried fruits, nuts, and cacao. These species often occur together on stored foods, e.g., E. elutella and E. cautellaon dried fruit, or E. kühniella and E. elutellaon grain. Sometimes all three are found together on the same product. To know what species are present is of considerable importance, since they differ in the amount of damage they are likely to do, in their resistance to fumigants, in the frequency with which they are recorded as pests of Other products, etc. It has not hitherto been possible to identify the larvae with certainty except by breeding them out, which is unsatisfactory, both because of the time it takes and because it frequently happens that many of the larvae confined in breeding cages die of “wilt.”