Description and molecular phylogeny of one new and one known needle nematode of the genus <italic>Paralongidorus</italic> (Nematoda: Longidoridae) from grapevine in Portugal using integrative approach.

A new and a known longidorid nematode, <italic>Paralongidorus lusitanicus</italic> n. sp. and <italic>Paralongidorus plesioepimikis</italic>, are described and illustrated from populations extracted from soil associated with grapevine (<italic>Vitis vinifera</italic> L.) from Escaroupim and Pó (central-Western Portugal), respectively. The new needle nematode <italic>P. lusitanicus</italic> n. sp. is characterised by a very large body size (8072-12,022 μm), an expanded and rounded lip region, <italic>ca</italic> 30 μm wide, with a clear constriction followed by a depression posterior to the amphidial aperture, amphidial fovea very large (11.0-19.0 μm), stirrup-shaped, with conspicuous slit-like aperture as shown in scanning electron microscopy studies, a very long and flexible odontostyle (180.0-223.0 μm), guiding ring located at 28.0-41.5 μm from anterior end, vulva anterior to the mid-body (34-41%), a dorsally convex-conoid tail with rounded terminus (29-42 μm long), bearing two or three pairs of caudal pores and males common (ratio 1:1.6 females) with spicules <italic>ca</italic> 80 μm long. Morphological and morphometric traits for <italic>P</italic>. <italic>plesioepimikis</italic> fit well with the original description, and is reported for the first time in Portugal. Integrative diagnosis of both species was completed with molecular data obtained using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA and partial 18S-rDNA. The phylogenetic relationships of these species with other <italic>Paralongidorus</italic> spp. using these three molecular markers indicated that <italic>P. lusitanicus</italic> n. sp. clustered together with other <italic>Paralongidorus</italic> spp. forming a sister clade with <italic>P</italic>. <italic>plesioepimikis</italic>, both of them sharing a large body, long odontostyle, an anteriorly located vulva and an expanded and rounded lip region with a clear constriction followed by a depression posterior to the amphidial aperture. [ABSTRACT FROM AUTHOR]