MELOIDOGYNE ULMI SP. N., A ROOT-KNOT NEMATODE FROM ELM

Abstract

A root-knot nematode, Meloidogyne ulmi sp. n. found on elm plants in Tuscany (Italy), is described and illustrated. M. ulmi sp. n. can be distinguished among Meloidogyne species with similar second stage juvenile tail lengths (24.2-37.5 µm in M. ulmi sp, n.) by a combination of characters: in the female stylet slender (12.0-15.7 µm long), moderately curved, knobs rounded or transversely ovoid, slightly concave anteriorly, perineal patterns oval with dorsal arch low to medium high, tail end area well delimited with punctations in some specimens, lateral field indistinct or marked by folds, sometimes by lateral lines at one or both sides; in the male lateral field areolated, usually with four, frequently with five to seven lines, labial cap shallowly rounded, one fifth to one fourth as high as the postlabial head region and a little narrower than the same region, stylet 17.5-22.9 µm long, with knobs rounded to pear shaped, more or less backwardly sloping; in the second stage juvenile lateral field areolated, usually marked by four, sometimes, five or six, lines, stylet short (8.5-11.1 µm long), hemizonid posteriorly adjacent or posterior to the excretory pore, tail conical, tapering to a finely rounded, almost pointed terminus or broader and rounded at the tip, cuticular constrictions along the hyaline part. Under SEM females, males and second stage juveniles show a labial disc set off from the medial lips. The only host plants so far known for M. ulmi sp. n. are Ulmus chenmoui and U. glabra.