Description of Aphelenchoides paratenuis n. sp. (Tylenchina: Aphelenchoididae) found in white ash (Fraxinus sp.) wood from the USA

Summary Aphelenchoides paratenuis n. sp. found in white ash ( Fraxinus sp.) wood from the USA is characterised by the male body length 767.6 (594-848) μ m and female length 824.1 (669-956) μ m, slim body shape (a = 48.5 (41.5-53.5) and 48.0 (41.9-56.8) for males and females, respectively). The lateral field has three lines, and the slender stylet is 9-12 μ m long with small basal swellings. The excretory pore is located at the level of the nerve ring. The hemizonid is obscure. The vagina is not sclerotised but with conspicuous sclerotised pieces encircling it, and the vulva has slightly protruding lips and lacks a flap. The PUS is well developed and comprises ca 33.0 (29.1-38.2)% of the vulva to anus distance. Spicules rose-thorn-shaped, strongly curved at two-thirds from dorsal limb, 17.1 (15.0-19.4) μ m long in curved median line, condylus rounded and high, rostrum rounded and short; the dorsal limb is 22.9 (19.2-28.9) μ m long, with slightly ventrally bent distal end. The spicules’ sheath-like structure is absent. The male tail bears three pairs (2 + 2 + 2) of caudal papillae. The tail of both sexes is sub-cylindrical and the terminus bears a bluntly pointed mucron with tiny nodular protuberances. The new species belongs to the Group 2 category of Aphelenchoides species sensu Shahina and defined as A2-B1-C1-D1-E2-F2 according to the categorisation codes of OEPP/EPPO. The new species is close to A. tenuis and A. yixingensis . Phylogenetic analyses based on sequences of partial 18S, ITS, and 28S D2-D3 of rDNA confirmed its status as a new species.