Larval feeding habits of the Hepialidae (Lepidoptera)

The host-plant relationships of the Hepialidae are discussed in relation to host range and larval tunnelling behaviour. Larvae are mostly phytophagous on live angiosperms, gymnosperms, pteridophytes and mosses. Generally they specialize as feeders of leaf, stem/branch or root tissue, but dietary transitions from leaf to stem and root to stem occur in some species. An early period of mycophagy where larvae feed on fungi or dead decaying plant tissue is recorded in a wide range of species that feed on live embryophytes in later instars. Feeding patterns of the Hepialidae are compared with those of other major lepidopteran taxa and the evolutionary implications of hepialid feeding habits for the origin and derivation of larval host-plant relationships in Lepidoptera are discussed. It is suggested that the developmental transition from mycophagy to phytophagy in the Hepialidae is the result of partial ‘suppression’ of mycophagy in the generalist feeding ancestor of Lepidoptera.