A Proposed New Species Complex within the Cosmopolitan Ring Nematode (de Man, 1921) Micoletzky, 1925.

Ring nematodes are obligate ectoparasites on cultivated and wild herbaceous and woody plants, inhabiting many types of soil, but particularly sandy soils. This study explored the morphometrical and molecular diversity of ring nematodes resembling in 222 soil samples from fruit crops in Spain, including almond, apricot, peach and plum, as well as populations from cultivated and wild olives, and common yew. Ring nematodes of the genus were detected in 12 samples from under spp. (5.5%), showing a low to moderate nematode soil densities in several localities from southeastern and northeastern Spain. The soil population densities of associated with spp. ranged from 1 nematode/500 cm of soil in apricot at Sástago (Zaragoza province) to 7950 and 42,491 nematodes/500 cm of soil in peach at Ricla and Calasparra (Murcia province), respectively. The integrative taxonomical analyses reveal the presence of two cryptic species identified using females, males (when available), and juveniles with detailed morphology, morphometry, and molecular markers (D2-D3, ITS, 18S, and COI), described herein as sp. nov. and sp. nov. All molecular markers from each species were obtained from the same individuals, and these individuals were also used for morphological and morphometric analyses. sp. nov. was found in a high soil density in two peach fields (7950 and 42,491 nematodes/500 cm of soil) showing the possibility of being pathogenic in some circumstances.