Six new species of Acomoptera from North America (Diptera, Mycetophilidae)

Six new species are described, raising the number of North American Acomoptera species to seven and the genus total to ten, and nearly doubling the number of species within the putative clade containing Acomoptera, Drepanocercus, and Paratinia. These novel species forms have implications for the concept of Acomoptera that in turn, may impact our understanding of its generic relationships and the evolution and composition of Gnoristinae and Sciophilinae. The new species, A. crispa, A. digitata, A. echinosa, A. forculata, A. nelsoni, and A. vockerothi, are compared with the type species of the genus, A. plexipus (Garrett), whose diagnostic features are imaged and illustrated for the first time. The European species, A. difficilis (Dziedzicki) is also illustrated and compared. Acomoptera spinistyla (Soli) comb. n. is transferred from Drepanocercus. A key to species is provided. Future work will seek to incorporate this knowledge into a systematic phylogenetic study of relationships between these species and their sister taxa.