This is a large and ubiquitous family, with species adapted to diverse terrestrial habitats. Many are pests of cultivated plants and stored products. Several subfamilies are recognized including the Galleriinae, Chrysauginae, Pyralinae and Phycitinae. The remainder of the subfamilies traditionally included in the Pyralidae are now included in the Crambidae which has been elevated to family rank based on the form of the tympanal organs.
Tympanal organs with tympanal case almost closed; conjunctiva and tympanum in the same plane; praecinctorium (a ventrally expanded, medial flap anterior to the tympanal organs) absent. Small to large moths;head smooth scaled, sometimes with anterior tuft, ocelli and chaetosema present or absent, antennae filiform and ciliated rarely uni- or bipectinate; proboscis densely scaled near base, sometimes reduced or vestigial; maxillary palps scaled, usually 4 segmented, sometimes 2 or 3 segmented, rarely vestigial, sometimes highly modified; labial palps porrect, beak-like or ascending, especially in male, rarely reduced; epiphysis present, spurs 0-2-4, rarely 0-2-2; fore wing without chorda and without M stem in cell, with R 3 and R 4 stalked or coincident, M 2 approximated to M 3 at base, CuP rarely present, 1A + 2A usually with a large fork; hindwing of female with 1-3 fenular bristles (1 in Phycitinae), Sc + R1 approximated to, or shortly fused with, Rs beyond discal cell, M 2 approximated to M 3 at base, CuA sometimes with basal pectin, CuP rarely absent, anal area large, with two anal veins, abdomen with coremata often present. Eggs of flat type, usually oval. Larva usually without secondary setae, prothorax with 2 L setae, crotchets usually bi- or triordinal, in a circle or mesal penelipse, rarely uni- or biordinal in two transverse bands; in shelters of webbed leaves or shoots, or tunnels in shoots, stems, seed heads, fruits, galls, or in silken galleries in herbaceous plants or fallen leaves or in stored products or in nests of Hymenoptera, rarely predaceous on Coccidae(HEMI). Pupa with pilifers defined, maxillary palps present (except Epipaschiinae), antennae long, abdomen without dorsal spines, cremaster present or absent; in silken cocoon or in larval shelter, not protruded at ecdysis.