Re-classification of Lycoriella Frey sensu lato (Diptera, Sciaridae), with description of Trichocoelina gen. n. and twenty new species

On the basis of re-evaluation of morphological characters of the Lycoriella group of genera and subgenera, generic rank is given to the two species groups belonging to Lycoriella (Hemineurina) Frey, 1942 and to Lycoriella (Coelostylina) Tuomikoski, 1960. The Lycoriella (Hemineurina) inflata group, including the type species of the subgenus, Sciara conspicua Winnertz, 1867, is treated as the genus Hemineurina stat. n. and the Lycoriella (Hemineurina) vitticollis group as the genus Trichocoelina gen. n. (type species Sciara vitticollis Holmgren, 1883). Coelostylina Tuomikoski, 1960 (type species Lycoriella (Coelostylina) freyi Tuomikoski, 1960) is a junior homonym of Coelostylina Kittl, 1894, and is renamed Stenacanthella nom. et stat. n. The genera are diagnosed and their phylogeny is discussed. Eight species are excluded from the Lycoriella group. They are transferred to the genera Bradysiopsis Tuomikoski, 1960, Camptochaeta Hippa & Vilkamaa, 1994, Merizomma Sasakawa, 2003 stat. n. and Scatopsciara Edwards, 1927 (five species) or are for the time being regarded as incertae sedis (two species) and as nomen nudum (one name). Numerous nomenclatural corrections are made also in the genera Hemineurina Frey, Stenacanthella Vilkamaa & Menzel and Trichocoelina Vilkamaa & Menzel. Altogether 42 new combinations, three changes in status and one new synonym are presented. A lectotype is designated for Hemineurina algida (Frey, 1948) and two Hemineurina species names are removed from synonymy and given full species status. The following species of Trichocoelina are newly described: Trichocoelina absidata sp. n. (Russia: Krasnodarsk region), T. aemula sp. n. (Finland, Russia: Krasnodarsk region), T. biplex sp. n. (Canada: Newfoundland and Labrador, Yukon), T. dicksoni sp. n. (Russia: Arkhangelsk oblast, Kemerovsk oblast, Krasnodarsk region), T. dispansa sp. n. (Russia: Krasnodarsk region), T. dividua sp. n. (Canada: Northwest Territories), T. hians sp. n. (Canada: Yukon), T. imitator sp. n. (Canada: Yukon), T. incrassata sp. n. (USA: Alaska), T. ithyspina sp. n. (Norway), T. jukkai sp. n. (Finland), T. magnifica sp. n. (Canada: Yukon), T. nefrens sp. n. (Russia: Krasnodarsk region), T. obesula sp. n. (Norway), T. oricillifera sp. n. (Finland, Norway), T. planilobata sp. n. (Finland), T. quintula sp. n. (Finland), T. semisphaera sp. n. (Finland, Norway), T. semusta sp. n. (Italy, USA: Alaska), and T. tecta sp. n. (Canada: Nunavut, Yukon, Russia: Krasnodarsk region, Yamalo-Nenets Autonomous Okrug, USA: Alaska). The Trichocoelina species are keyed, the 20 new species are described and illustrated, and the 9 previously known ones, transferred to the new genus, are briefly diagnosed and the taxonomically relevant literature regarding them is listed. Trichocoelina janetscheki (Lengersdorf, 1953) comb. n. and Trichocoelina brevicubitalis (Lengersdorf, 1926) comb. n. are redescribed. The genus Trichocoelina currently includes 29 species: 17 in the Palaearctic, 6 in the Nearctic and 6 in the Holarctic. All known species are northern or montane.