Morphological and molecular characterisation of Xiphinema macroacanthum Lamberti, Roca & Agostinelli, 1989 (Nematoda: Longidoridae) from olive orchards in southern Italy

A population of Xiphinema macroacanthum Lamberti, Roca & Agostinelli, 1989 originating from olive orchards in Brindisi, Italy and containing both adults and all juvenile stages, is described and illustrated. The first juvenile stage is reported for the first time. Molecular characterisation of this species, using the D2–D3 expansion domains of the 28S rDNA and ITS region, was carried out. PCR–RFLP analyses of the ribosomal gene regions determined species-specific patterns that clearly differentiate X. macroacanthum. Sequences of the D2–D3 domains and the partial 18S-ITS1 rRNA genes were analysed using several methods for inferring phylogeny to reconstruct the relationships between X. macroacanthum and other Xiphinema species.