Description of Basilaphelenchus laricis sp. n. (Rhabditida: Aphelenchoididae: Tylaphelenchinae) from Shanxi province, north China

Summary Basilaphelenchus laricis sp. n. is described and illustrated from bark of a dead larch tree, Larix gmelinii var. principis-rupprechtii , from Shanxi province, northern China. The new species is characterised by having females 357-482 μ m long, the cephalic region with six labial sectors divided by ribs, lateral field with three incisures, stylet short, 7-8 μ m long, with three elongate, posteriorly directed knobs, posteriorly located median bulb valve, post-vulval uterine sac (PUS) 57-67 μ m long, tail smoothly tapering to variously-shaped tip, male spicules 8-9 μ m long, with a distinct capitulum featuring a shallow depression in the middle, condylus roundish, rostrum blunt and spicules tip simple, three pairs of caudal papillae and tail with a sharp terminal mucron. Molecular phylogenetic inferences using partial sequences of small subunit (SSU) and D2-D3 segments of large subunit (LSU) of ribosomal DNA (rDNA) from the new species revealed that it belongs to Basilaphelenchus , and is distinct from other members of the genus, including the two cryptic species B. gorganensis and B. pedrami .