Orphella intropus (Kickxellomycotina), a new insect endosymbiont with an unusual perforating holdfast system and other trichomycetes from Italy

New data about trichomycetes (arthropod gut endosymbionts) from northern Italy (Piedmont [Piemonte] region) are reported, including the description of two new species of Harpellales: Glotzia distorta from mayfly nymphs and Orphella intropus from stonefly nymphs. The latter species is characterized by a cellular bulbous holdfast that perforates the gut lining of its host. Sixteen additional geographical records for Italy are provided, including from the Harpellales, Harpellomyces eccentricus, Graminella bulbosa, Orphella catalaunica, Pennella grassei, Smittium perforatum, Sm. elongatum, Stachylina nana, St. jujuyensis, St penetralis and Tectimyces leptophlebiidarum, and from the Amoebidiales, Paramoebidium chattoni, P. corpulentum, P. curvum, P. ecdyonuridae, P. hamatum and P. inflexum. We provide an emendation of Pennella grassei, a rare, incompletely described and poorly illustrated species that was recovered from Italy nearly 50 y after its last citation from France. © 2014 by The Mycological Society of America.