Harpellales in Newfoundland aquatic insect larvae

Abstract

Among nine Harpellales (Trichomycetes) reported from aquatic insect larvae collected in Newfoundland, Canada, four new species are described: Harpellomyces abruptus [living in Thaumalea verralli (Diptera: Thaumaleidae)], Orphella avalonensis [in Leuctra ferruginea (Plecoptera: Leuctridae)], Stachylina litoralis [in Telmatogeton japonicus (Diptera: Chironomidae)], and an unnamed species of Smittium (in Chironomidae) from which an axenic culture was obtained. Other Harpellales were from Simuliidae (Harpella melusinae, Pennella simulii, Simuliomyces microsporus), Chironomidae (Stachylina robusta), and an unnamed new genus in caddis fly larvae (Trichoptera). Low vagility of Plecoptera and the occurrence of different species of Orphella in the USA and Europe suggest that the genus existed before the North Atlantic formed a barrier as the continents separated. It is hypothesized that vicariant speciation may have occurred in Orphella as well as in Harpellomyces from Thaumaleidae larvae.

Key Words:

• biogeography
• Chironomidae
• gut fungi
• Leuctridae
• Simuliidae
• symbiosis
• Thaumaleidae
• Trichomycetes
• Trichoptera