• S.V. Zinovieva, Z.V. Udalova,  I.S. Vasiljeva and V.A. Paseschnichenko. Action of sterol glycosides on Meloidogyne incognita infecting tomato and cucumber roots, 77-80
• J. Abolafia. and R. Pena Santiago. Nematodes of the order Dorylaimda from Andalucia Oriental, Spain. The genus Mesodorylaimus Andrassy, 1959. II. Two new species with pre- and/or postvulval ornamentations, 81-88
• R. Pena Santiago and G. Liebanas.  Nematodes of the order Dorylaimda from Andalucia Oriental, Spain. The genus Nygolaimus Cobb, 1913. IV. Description of N. seguranus sp. n. and its relationship with N. europaeus (Heyns, 1968) Ahmad & Jairajpuri, 1982, 89-95
• E.N. Romanenko,  J.G. Geltzer and N.D. Romanenko. The effect of soil disturbance in a spruce forest on the abundance of nematode trophic groups, 97-101
• O.V.Slobodyanyuk. Revision of the species Psyllotylenchus pawlowskyi (Kurochkin, 1960) Poinar & Nelson, 1973. I. Redescription of Spilotylenchus pawlowskyi (sensu stricto) comb. n. (Tylenchida: Allantonematidae), 103-112
• L. Wasilewska. Soil invertebrates as bioindicators, with special reference to soil-inhabiting nematodes, 113-126
• S.E. Spiridonov. and E.S. Ivanova. Filiponema baviense sp. n. (Rhabditida: Drilonematoidea), a parasite of megascolecid earthworms from the Ba Vi National park, Vietnam, 127-130
• E.D. Krasnova and A.N. Pegova. Individual and micro-geographical variability of the marine nematode Metachromadora vivipara de Man 1907, (Chromadoria: Desmodorida) in the White Sea, 131-136
• A. Ryss. Computerized identification of species of the genus Radopholus (Tylenchida: Pratylenchidae), 137-142
• S.A. Subbotin,  D. Sturhan, L. Waeyenberge and M. Moens. Heterodera riparia sp. n. (Tylenchida: Heteroderidae) from common nettle, Urtica dioica L., and rDNA-RFLP separation of species from the H. humuli group, 143-157
• Book Reviews, 158-163.

Zinovieva, S. V., Udalova, Z. V., Vasiljeva, I. S. and Paseschnichenko, V. A.

Action of sterol glycosides on Meloidogyne incognita infecting tomato and cucumber roots

Summary:
Treatment of tomato and cucumber plants with furostanol glycosides obtained from cell cultures of Dioscorea deltoidea Wall. decreased their susceptibility to infection by the root-knot nematode Meloidogyne incognita. In treated plants the fecundity of the nematode was decreased five-fold, females were smaller and the sex ratio shifted toward an increase in males.

Key words: cucumber, furostanol glycosides, induction, Meloidogyne incognita, resistance, tomato.

Abolafia, J. and Pena Santiago, R.

Nematodes of the order Dorylaimda from Andalucia Oriental, Spain. The genus Mesodorylaimus Andrassy, 1959. II. Two new species with pre- and/or postvulval ornamentations

Summary:
Two new species belonging to the genus Mesodorylaimus Andrassy, 1959 are described from natural biotopes in southeastern Spain. Mesodorylaimus ibericus sp. n. is characterized by its medium sized body (L=1.2-1.8 mm), lip region offset by a depression or almost continuous, odontostyle 12.5-15 µm or scarcely longer than the lip region width, V=48-58%, vulva longitudinal, presence of small irregularities of the outer cuticle next to the vulva, pars refringens vaginae consisting of two well developed and separated triangular sclerotizations, female tail long (62-112 µm, c=14-24, c'=2.4-4.6) in general with the ventral side straight and the dorsal one first convex and then concave, and males unknown. Mesodorylaimus ornativulvatus sp. n. can be distinguished by its small to medium body size (L=0.9-1.1mm), lip region offset by a depression, odontostyle 10-11 µm, V=44-52%, presence of abundant wrinkles and folds on the body cuticle next to the vulva region, pars refringens vaginae consisting of two well developed close arrow-head shaped or triangular sclerotizations, female tail filiform (94-144 µm, c=8-11, c'5.5-8), male tail rounded (19-25 µm, c=45-57, c'=0.8-1.0), spicules 40-54 µm and 8-10 regularly spaced ventromedian supplements beginning outside the range of the spicules.

Key words: description, Mesodorylaimus ibericus, Mesodorylaimus ornativulvatus, Spain.

Pena Santiago, R. and Liebanas, G.

Nematodes of the order Dorylaimda from Andalucia Oriental, Spain. The genus Nygolaimus Cobb, 1913. IV. Description of N. seguranus sp. n. and its relationship with N. europaeus (Heyns, 1968) Ahmad & Jairajpuri, 1982.

Summary:
Nygolaimus seguranus sp. n. is described from natural biotopes in southeastern Spain. The species is characterized by its medium sized (L=1.1-1.7 mm) body, lip region set off by a constriction and 11-12.5 µm wide, deltoid mural tooth 10.5-12.5 µm long at the dorsal side or almost equal to the lip region width, pharyngeal bulb encapsulated by a spiral sheath, V=47.8-57.1%, female tail rounded, conoid (17-20.5 µm, c=66.6-84.4, c'=0.9-1.1), male with no or only one ventromedian supplement, and spicules 27-27.5 µm long. The new species is most similar to N. europaeus (Heyns, 1968) Ahmad & Jairajpuri, 1982, the type specimens of which were examined during preparation of the description of the new species. Both species are illustrated, tables of measurements are given,
and their relationship is briefly discussed.

Key words: Nygolaimus europaeus, Nygolaimus seguranus sp. n., Spain, taxonomy.

Romanenko, E. N., Geltzer, J. G. and Romanenko, N.D.

The effect of soil disturbance in a spruce forest on the abundance of nematode trophic groups

Summary:
Changes in the soil nematode fauna of a natural spruce forest caused by the laying of a gas pipeline were studied in the Moscow region. In the disturbed soil there was a significant reduction in nematode abundance, with fewer saprophagous, bacteriophagous and omnivores present. These changes were correlated with mixing of the soil horizons, change of vegetation and a reduction in organic matter.

Key words: distribution, nematodes, soil disturbance, trophic groups.

Slobodyanyuk, O. V.

Revision of the species Psyllotylenchus pawlowskyi (Kurochkin, 1960) Poinar & Nelson, 1973. I. Redescription of Spilotylenchus pawlowskyi (sensu stricto) comb. n. (Tylenchida: Allantonematidae)

Summary:
The diagnosis and taxonomic status of the species Psyllotylenchus pawlowskyi Kurochkin, 1960 were investigated. The nematodes were originally described from two species of fleas, Coptopsylla lamellifer and Nosopsyllus laeviceps, but the type specimens have been destroyed or lost. New specimens were obtained from fleas collected at the type locality and were used to prepare a redescription of the species. Psyllotylenchus pawlowskyi sensu Kurochkin, 1960 was found to be a complex of three species: Spilotylenchus pawlowskyi (sensu stricto) comb. n. a parasite of the flea C. lamellifer, and two nematode species which parasitize the flea N. laeviceps. A neotype of S. pawlowskyi (sensu stricto) comb. n. is designated and the species is distinguished from all other Spilotylenchus species by the body length of the parasitic female, shape of stylet and position of the excretory pore.

Key words: biology, flea parasites, neotype, Psyllotylenchus pawlowskyi (sensu lato), Spilotylenchus pawlowskyi (sensu stricto) comb. n. .

Wasilewska, L.

Soil invertebrates as bioindicators, with special reference to soil-inhabiting nematodes.

Summary:
Advantages of using terrestrial nematodes as bioindicators are reviewed. Fifty two studies published between 1990-1996, which used nematodes as indicators of a variety of soil processes, were examined as part of the review. A distinction was made between publications reporting changes in populations of indicator species, and those which referred to changes at the community level. The Maturity Index, which provides a measure of successional maturity, has recently attained special significance, therefore studies examining primary and secondary succession were also included. Considering pollution and perturbation in an ecosystem as distortions of the natural process of succession, facilitates an assessment of the quality of environments differing in vegetation type, plant age, management regime and the temporal effect of stress. Thus, it becomes possible to evaluate the return to a previous state following the disappearance of an induced stress.

Key words: bioindication, disturbance, diversity, ecological ratios, maturity indices, soil nematodes, succession, trophic groups.

Spiridonov, S.E. and Ivanova, E. S.

Filiponema baviense sp. n. (Rhabditida: Drilonematoidea), a parasite of megascolecid earthworms from the Ba Vi National park, Vietnam

Summary:
Filiponema baviense sp. n. is described from specimens recovered from the coelomic cavity of megascolecid earthworms collected at the altitude of 1100 m on Ba Vi mountain, Vietnam. Filiponema baviense sp. n. is distinguished from congeners by its bifurcated spicular distal end and by the size and structure of its receptaculum seminis. Fibrous filling present in the anterior pseudocoel and an oesophageal constriction close to the stomatal opening resemble the morphology of Pharyngonema mekongianum Pierantoni, 1923. The diagnosis of Filiponema Timm & Maggenti, 1966 is revised.

Key words: Drilonematidae, earthworm host, Filiponema, Filiponema baviense sp. n., morphology.

Krasnova, E.D. and Pegova, A.N.

Individual and micro-geographical variability of the marine nematode Metachromadora vivipara de Man 1907, (Chromadoria: Desmodorida) in the White Sea.

Summary:
Males of Metachromadora vivipara from eight localities in the vicinity of the White Sea Biological station of Moscow State University differed in the number of preanal supplements (NPS) present and in their karyotype. Karyotypes of M. vivipara from populations with a mean NPS greater than 20 had optional B-chromosomes. Conversely, populations of M. vivipara with a mean NPS less than 20 did not contain B-chromosomes. This correlation is considered evidence of a genetic basis for the polymorphism. These two features were used to distinguish the populations examined into three groups. Differences in mean NPS were stable during several years of study. Populations with similar characters had close geographical affinity and distances of only a few kilometres were sufficient for the populations to be distinct.

Key words: B-chromosomes, karyotype, Metachromadora vivipara, variability, White Sea

Ryss, A.

Computerized identification of species of the genus Radopholus (Tylenchida: Pratylenchidae)

Summary:
A polytomous identification key for 24 species of Radopholus was constructed using the computer software packages EXCEL 5.0, spreadsheets and BIKEY 7 (Lobanov & Dianov, 1994). Specimen identification is based on the principle that the initial set of taxa can be investigated interactively and reduced by different filters (i.e. character states) in several steps of identification. Quantitative characters are best utilised by EXCEL which can filter, using 'Autofilter', 'Advanced Filter' or 'Sort', initial assemblages of taxa by a set of several characters at each step. Conversely, BIKEY has preferences to utilise qualitative characters and uses images during selection of character states, with text explanations providing only an auxiliary aid. This package provides a list of characters, arranged in descending order depending on their diagnostic value (not at random). In constructing the identification key for Radopholus it was determined that 20 characters are sufficient to identify 24 species, with an average identification path of only 5196 steps. The most important characters are: number of incisures from phasmid to tail terminus, sperm shape, tail terminus shape, tail terminus annulation, relative width of the central band in lateral field, number of cephalic annules, number of incisures in lateral field, and difference in size between the anterior and posterior spematheca.

Key words: computerized key, Radopholus, pictorial key, taxonomy

Subbotin, S.A., Sturhan, D., Waeyenberge, L. and Moens, M.

Heterodera riparia sp. n. (Tylenchida: Heteroderidae) from common nettle, Urtica dioica L., and rDNA-RFLP separation of species from the H. humuli group.

Summary:
Heterodera riparia sp. n. from roots of Urtica dioica L. is described based on materials collected from plants growing at the sides of rivers, ponds and lakes in Russia, Germany and Belgium. The new species is similar to H. humuli, but differs by its smaller average cyst size (415-468 µm vs. 452-524 µm in H. humuli) and shorter average fenestra length (46-52 µm vs. 56-61 µm). The second stage juveniles of Heterodera riparia sp. n. have a lower average body length (350-373 µm vs. generally > 375 µm), a shorter tail (40-47 µm vs. 50-57 µm) and a shorter hyaline part of tail (18-23 µm vs. generally > 27 µm). One generation of the nematode developed during the vegetative season. Restriction enzyme analysis of ribosomal DNA sequences was used to distinguish Heterodera riparia sp. n. from the related species H. humuli and H. fici. The pattern of restriction bands obtained with AluI clearly distinguished all species from each other and the enzymes CfoI and PstI also distinguished the new species from the other species. The distribution of the new species in Europe is reported.

Key words: cyst nematodes, distribution, Heterodera riparia sp. n., H. fici, H. humuli, ITS, morphometrics, PCR, RFLP.