|SIDDIQI, MOHAMMAD RAFIQ - NEMATODE TAXONOMY LABORATORY|
Submitted to: International Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2015
Publication Date: 8/11/2015
Publication URL: http://handle.nal.usda.gov/10113/61263
Citation: Siddiqi, M., Handoo, Z.A., Chitwood, D.J. 2015. 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. International Journal of Nematology. 25(1):77-89.
Interpretive Summary: Nematodes are microscopic worms that live in the soil. Some feed on plants and cause crop diseases exceeding $100 billion annually; others are beneficial to agriculture because they are predators that prey on a wide variety of soil-inhabiting organisms, including plant-parasitic nematodes. One major agricultural problem is that the species of predatory nematodes in a particular field are often unknown to science. In this study, a scientist from England and ARS scientists from Beltsville, Maryland examined specimens of several species of predaceous nematodes with a large tooth used for feeding on prey. These species were redescribed and illustrated, and two new species of nematodes were proposed. These descriptions are significant because they provide new methods for easily distinguishing different species from each other. This research will be used by scientists designing strategies for enhancing the roles of beneficial predaceous nematodes as possible biological control agents in agricultural soils.
Technical Abstract: 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 so we describe topotypes and propose neotypes for each 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.