Taxonomy and Postembryonic Stages of the Nematode Predator Odontopharynx longicaudata de Man, 1912 (Diplogasterida)

Odontopharynx longicaudata (Diplogasterida: Odontopharyngidae) was found in soil around roots of Poa annua L. growing on a golf course in San Francisco, California. This is the first record of this species in the United States. Populations of O. longicaudata were increased in the laboratory on the free-living nematode UCD Acrobeloides No. 1 (Rhabditida: Cephalobidae). Light microscopy was used to compare the morphology of fixed specimens from California and The Netherlands. California specimens were studied in greater detail by scanning electron microscopy. Emended descriptions are given for the genus and species, as well as the diagnostic morphological characters of the juvenile stages. The species is distinguished by the number and position of stomatal teeth (seven anterior, six posterior); vulva position (41-65%), length of the paired postuterine sacs (left 35-78 mum, right 29-73 mum); size and shape of the spicules and gubernaculum, and by number and position of the preanal papillae (two subventral pairs, one ventral papilla), anal papillae (one lateral pair), and caudal papillae (one pair anterior to phasmid, four posterior pairs). A neotype is designated from The Netherland collection.