Molecular Phylogeny and Species Delimiting for the Genus (Nematoda: Tylenchida) with Description of sp. n. and Notes on Biogeography of the Genus in the United States.

Lance nematodes, spp., feed on the roots of many kinds of plants, including agronomic crops. In this study, morphological and molecular analyses of several species and populations are provided. We were able to collect and characterize the topotype materials of from Arlington, Virginia; syn. n. from Nichols, South Carolina; and from Pensacola, Florida, and several additional populations and species from the United States, Israel, and India. Phylogenetic analyses of several hundred sequences of the D2-D3 expansion regions of 28S rRNA, ITS rRNA, and COI genes of species obtained from published and original datasets were given. Fifty-three new D2-D3 of 28S rRNA, 43 new ITS rRNA, and 47 new sequences from 23 isolates of spp. and one isolate of were obtained in this study. New molecular identities for and were proposed. syn. n. was considered a synonym of based on the morphological and molecular similarity of these two species. Analysis of morphology and molecular data did not reveal significant differences among syn. n., syn. n., and , and the first two species were synonymized with . A new species, sp. n., was described from many locations in Florida, USA. It was separated from other representatives of the genus by its morphological and molecular characteristics. Maps with geographical distribution of several lance nematode species in North America were reconstructed based on published and original molecular identification of samples.