The root-knot nematodes of the genus Meloidogyne are highly adapted, obligate plant parasites, consisting of nearly one hundred valid species, and are considered the most economically important group of plant-parasitic nematodes. Six Meloidogyne species: M. arenaria, M. hapla, M. incognita, M. microtyla, M. naasi and M. nataliei were previously reported in Michigan, USA. For this study, Meloidogyne nataliei was isolated from the grapevine Vitis labrusca from the type locality in Michigan, USA, and was characterized using isozyme analysis and ribosomal and mitochondrial gene sequences. No malate dehydrogenase activity was detected using macerate of one, five, six, seven or ten females of M. nataliei per well. However, one strong band (EST = S1; Rm: 27.4) of esterase activity was detected when using homogenates of ten egg-laying females per well. Phylogenetic analyses of sequences of the partial 18S ribosomal RNA, D2-D3 of 28S rRNA, internal transcribed spacer of rRNA, mitochondrial cytochrome oxidase subunit I genes and the cytochrome oxidase subunit II-16S rRNA intergeneric fragment from fifty-five valid Meloidogyne species and M. nataliei were conducted using Bayesian inference and maximum likelihood methods. From these results, we infer 11 distinct clades among studied species, with M. nataliei and M. indica composing a basal lineage. Seventy five percent of these species belong to seven clades within the Meloidogyne superclade. Characterization of these clades is provided and evolutionary trends within the root-knot nematodes are discussed.

Nevadanema nevadense gen. n., sp. n. is described from natural highlands in the south-eastern Iberian Peninsula and is characterised on the basis of morphological, morphometric and molecular (D2/D3-LSU rDNA) data, including SEM study. The new genus is mainly distinguishable by its rounded and offset lip region with amalgamated lips, odontostyle comparatively attenuated, guiding ring double, odontophore rod-like, female genital system amphidelphic, pars refringens vaginae present, and short and rounded tail. It is morphologically close to Labronema, from which it differs in the nature of the lip region and odontostyle. Two species of Labronema, namely L. fimbriatum and L. uniforme, are transferred to the new genus.

Two Florida populations of foliar nematodes were collected from strawberries originating from Cashiers, North Carolina (USA) located west from Willard, the type locality of Aphelenchoides besseyi. Both nematodes were cultured on Monilinia fructicola and identified using morphological characteristics and molecular assays as Aphelenchoides besseyi and Aphelenchoides pseudogoodeyi sp. n., a herein described new species related to Aphelenchoides goodeyi belonging to the Group of Aphelenchoides exhibiting stellate tails. The morphological and biological characters of Florida A. besseyi fit those of the original description of this species. A. pseudogoodeyi sp. n., which was initially misidentified as Aphelenchoides fujianensis, differed from the type population of the latter species from China because it was without males, and females lacked a functional spermatheca, whereas type A. fujianensis is an amphimictic species. Phylogenetic analyses using near full-length 18S ribosomal RNA (rRNA), the D2-D3 expansion fragments of 28S rRNA, and partial COI gene sequences indicated that A. besseyi is a species complex. A. pseudogoodeyi sp. n. grouped in different clades from those of the type A. fujianensis, instead merging with populations identified of ‘A. fujianensis’ from Brazil and other countries, suggesting that the latter are conspecific and incorrectly identified. The Florida A. besseyi infected strawberry and gerbera daisy, but not soybean and alfalfa. A. pseudogoodeyi sp. n. is mainly mycetophagous. Localized inoculation of 300 specimens applied with filter paper adhering to the blade of the soybean leaves resulted in nematode penetration into the mesophyll with subsequent development of lesions limited to the inoculated area of the blade.

The taxonomy of the genus Aporcelaimellus is revised and updated. A new definition is proposed, with several remarkable diagnostic characters: cuticle three-layered, especially distinguishable at caudal region, usually bearing a hyaline space between inner and intermediate layers at terminal portion of tail; cervical lacunae often present and well developed; oral aperture a dorso-ventral, hexagonal open slit; lip region showing bilateral symmetry and offset by a more or less distinct constriction; odontostyle short, robust and with wide aperture; uterus simple, bi- or tripartite; pars refringens vaginae present, well developed; tail similar in both sexes, short, rounded to conical with more or less rounded terminus; and ventromedian supplements 7–25 in number, separated, almost always with pre-cloacal space (hiatus). A list of 28 valid species and their synonyms is provided as well as a key to their identification and a tabular compendium of their morpho-metrics. Aporcelaimellus faridpuriensis is considered to be a species inquirenda. Twenty-one species are regarded as in-certae sedis: A. amplexor, A. budauniensis, A. canis, A. digicaudatus, Dorylaimus domus glauci, A. estonicus, A. gerlachi, A. goldeni, A. index, A. jairajpurii, A. monodelphus, A. nawabganjense, A. nivalis, A. paracentrocercus, A. paraobtusicau-datus, A. radicus, A. sacchari, A. seinhorsti, A. stilus, A. submissus and A. subsimilis. Two species are retained under other genera: A. bicuticulus under Labronema, and A. cocophilus under Aporcelaimus. Sixteen species are transferred to other genera: A. baqrii and A. odhneri to Crassolabium; A. dubius to Discolaimium as Discolaimium geraldi nom. n.; A. duhouxi to Labronema; A. glandus, A. heynsi, A. maitai and A. paraconicaudatus to Discolaimium; A. insularis, A. jiaonanensis, A. kikereensis and A. propinquus to Aporcelinus; A. maximus to Aporcella; A. paracentrocercus apud Andrássy (1960) to Aporcelinus as Aporcelinus africanus sp. n.; A. saprophilus to Eudorylaimus; and A. tritici to Makatinus. Finally, A. con-cavus becomes a non-valid binomen.

This contribution presents a study of Iberian and Californian populations of Aporcelaimellus simplex, including morphological, morphometric and molecular data. The species is characterised and distinguished by its lip region offset by an expansion, pars refringens vaginae absent, and conical tail with a small but distinct hyaline terminal portion. No significant difference exists between American and European populations. Molecular data and the derived evolutionary tree show a topology in which this species forms a well-supported group with members of Discolaiminae, far from other representatives of Aporcelaimellus. Putting special emphasis in the absence of pars refringens vaginae, A. simplex is transferred to the genus Aporcella. The taxonomy of this genus is revised in depth, with the proposal of an emended diagnosis, the provision of a list of 13 valid species (mostly new combinations from Aporcelaimellus) as well as a key to their identification and a compendium of their main morphometrics. Aporcella debruinae sp. n. is proposed for Aporcelaimellus papillatus apud de Bruin & Heyns, 1992.