Description of a new needle nematode, Longidorus asiaticus n. sp. (Nematoda: Longidoridae), from the rhizosphere of crape myrtle (Lagerstroemia indica) bonsai trees imported into Italy from China

Abstract

A new longidorid nematode, Longidorus asiaticus n. sp., is described and illustrated from a population extracted from soil associated with the movement of crape myrtle (Lagerstroemia indica) flowering bonsai trees imported from China into Italy. The new needle nematode is characterised by a small body size (2.74–3.52 mm), a bluntly-rounded lip region, ca 12 μm wide, continuous with body contour, amphidial fovea pocket-shape with posterior end rounded not bilobed, a moderately long and flexible odontostyle ca 85 μm long, stylet guiding ring located at ca 37 μm from anterior end, vulva almost equatorial (48–54 %), tail short, about 2/3 of its width, dorsally convex-conoid, with rounded terminus, with a c’ ratio ca 0.7, bearing two pairs of caudal pores and male absent. Integrative diagnosis was completed with molecular data obtained using D2-D3 expansion segments of 28S rDNA, ITS-rDNA, and partial 18S-rDNA. The phylogenetic relationships of this species with other Longidorus spp. using D2-D3 expansion segments, ITS and partial 18S-rDNA indicated that L. asiaticus n. sp. clustered together with L. hangzhouensis, Longidorus sp. JH-2014, and L. camelliae: all of them sharing a common Asiatic geographic origin.