A key to the fully grown larvae of 11 species of Phycitinae is given. Of these, the following eight are known in Britain either as stored-products pests or associated with imported food:— Ephestia elutella (Hb.), Anagasta kuehniella (Zell.), Cadra cautella (Wlk.), C. calidella (Gn.), C. figulilella (Gregson), Plodia interpunctella (Hb.), Mussidia nigrivenella Rag. and Ectomyelois ceratoniae (Zell.). The key is preceded by a brief account of the economic importance of these species in Britain.
The other three species are Ectomyelois decolor (Zell.), E. muriscis (Dyar) and Paramyelois transitella (Wlk.). Although these are native to the Americas and are unknown in Britain, they comprise, together with E. ceratoniae, the economically important species formerly of the genus Myelois Huebner.
The larvae of Mussidia nigrivenella, P. transitella and of the three species of Ectomyelois are described.