On the identity of Mononchus digiturus Cobb, 1893, Mononchus minor Cobb, 1893, Mononchus trionchus Thorne, 1924, Mononchus montanus Thorne, 1924, and Mononchus amphigonicus Thorne, 1924

摘要

Identities of five ancient known species of Mononchida, namely Mononchus digiturus Cobb, 1893, M. minor Cobb, 1893, M. trionchus Thorne, 1924, M. montanus Thorne, 1924, and M. amphigonicus Thorne, 1924 have been reassessed. These are redescribed and illustrated and their systematic positions and relationships discussed. The descriptions are based on type specimens preserved in the USDA Nematode Collection, Beltsville, Maryland, USA except for M. digiturus and M. minor of which no types are extant sowe describe topotypes and propose neotypes for these species. Due to the absence of holotypes in original type specimens we have proposed lectotypes for Miconchus trionchus and Mononchus amphigonicus. These redescriptions have solved many existing taxonomic problems which are reported in this paper. Two new genera have been proposed, namely, Montonchus for Mononchus montanum Thorne, which is transferred to it as Montonchus montanus comb, n and Thorneum for Mononchus amphigonicus Thorne which becomes Thorneum amphigonicum comb. n. The latter species is transferred from Jensenonchus to Thorneum. Comiconchus Jairajpuri & Khan, 1982, based on Mononchus trionchus Thorne, 1924 is synonymized with Miconchus and the species returned to it.