Corticioid basidiomycetes associated with bark beetles, including seven new Entomocorticium species from North America and Cylindrobasidium ipidophilum, comb. nov.

Seven new Entomocorticium species (Peniophoraceae) are described based on morphology and phylogenetic analyses. Along with the type species (E. dendroctoni), Entomocorticium comprises eight species of nutritional symbionts of pine bark beetles in North America. Entomocorticium cobbii is the mycangial associate of the southern pine beetle, Dendroctonus frontalis, and E. parmeteri is the mycangial associate of the western pine beetle, D. brevicomis. Entomocorticium whitneyi, E. portiae, E. kirisitsii, E. oberwinkleri and the previously described E. dendroctoni have been isolated from galleries of D. ponderosae and D. jeffreyi in western North America. Entomocorticium sullivanii forms an ambrosia-like layer of basidia and basidiospores in the pupal chambers of Ips avulsus in the southeastern USA. Entomocorticium is phylogenetically placed within Peniophora, a corticioid genus of wood decay fungi with wind-dispersed basidiospores. At least four species of Entomocorticium produce basidiospores on basidia with reduced sterigmata that apparently do not forcibly discharge basidiospores. Another basidiomycete, Gloeocystidium ipidophilum, was described from Ips typographus galleries in Europe, but it is phylogenetically and taxonomically placed in another genus of wood decay fungi as Cylindrobasidium ipidophilum (Physalacriaceae). The free-living wood-decay fungus Phlebiopsis gigantea (Phanerochaetaceae) has been occasionally associated with bark beetles but is unrelated to C. ipidophilum or Entomocorticium.