Harpellales in Newfoundland aquatic insect larvae

Among nine Harpellales (Trichomycetes) reported from aquatic insect larvae collected in Newfoundland, Canada, four new species are described: Harpello myces abruptus [living in Thaumalea verralli (Diptera: Thaumaleidae)], Orph ella avalonensis [in Letactra ferruginea (Plecoptera: Leuctridae)], Stachyl ina litoralis [in Telmatogeton japonicus (Diptera: Chironomidae)], and an u nnamed species of Smittium (in Chironomidae) from which an axenic culture w as obtained. Other Harpellales were from Simuliidae (Harpella melusinae, Pe nnella simulii, Simuliomyces microsporus), Chironomidae (Stachylina robusta ), and an unnamed new genus in caddis fly larvae (Trichoptera). Low vagilit y of Plecoptera and the occurrence of different species of Orphella in the USA and Europe suggest that the genus existed before the North Atlantic fun ned a barrier as the continents separated. It is hypothesized that vicarian t speciation may have occurred in Orphella as well as in Harpellomyces from Thaumaleidae larvae.