Phylogeny and redescription of Laimaphelenchus pannocaudus Massey, 1966 (Rhabditida: Aphelenchoididae) intercepted from Canadian Picea glauca

Abstract

Summary Laimaphelenchus pannocaudus, isolated in Ningbo port from Picea gluaca, is redescribed based upon characteristic morphological details elucidated by light and scanning electron microscopy photographs. The recovered population is characterised by 907 (771-1024) μm long females with 11.2 (8.9-12.2) μm long stylet, four incisures in the lateral field, excretory pore located at the same level as, or slightly anterior to the nerve ring, vulva lacking a flap and located at 68.7 (63.9-73.4)% of the body, elongate post-vulval uterine sac 78.5 (55.6-101.1) μm long, and tail 40.6 (33.4-45.6) μm long. Males are common and characterised by 16.5 (15.7-17.8) μm long spicules (chord) with their condylus slightly recurved, squared to rounded in shape with a blunt rounded tip and rostrum triangular with a bluntly pointed tip, and six visible caudal papillae. The female tail is ventrally curved, conoid and bears a stalk-like terminus with 4-8 pedunculate projections. Phylogenetic analyses using partial 18S and 28S rDNA D2-D3 data revealed that L. pannocaudus formed a sister relationship with L. suberensis in both phylogenies.