Maria Teresa Vinciguerra

Steinernema vulcanicum n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode species from Sicily (Italy)

A new species of entomopathogenic nematode, Steinernema vulcanicum n. sp., is described from the slopes of Mount Etna (Sicily, Italy). It was recovered from soil in a chestnut wood. Molecular and morphological data indicate that the new species belongs to the glaseri group of Steinernema spp. The new species can be distinguished from the other described species of the group by morphological characteristics, crossbreeding tests and by the DNA sequences of ITS1 rDNA, 12S and cox1 mitochondrial loci. Steinernema vulcanicum n. sp. is characterised by the long and slender male spicules, with manubrium wider than long, velum prominent, rounded tip with ventral concavity and tail without mucro. The female has double epiptygmata in both generations. The third-stage infective juveniles have an average body length of 1200 μm, excretory pore generally located level with posterior part of the pharyngeal corpus (D% = 47-68), lateral field pattern of variable formula and hyaline part of tail forming ca 50% of its length. The DNA sequences, life cycle and the endosymbiotic bacterium of S. vulcanicum n. sp., Xenorhabdus kozodoii, indicate the similarity of the new species with S. arenarium, S. apuliae and S. boemarei, from which it can be distinguished by both morphological and molecular characters.

Role of nematodes in the biological processes of the soil

Abstract Nematodes are a quantitatively significant component of the soil microfauna: the number of individuals per m2 is measured in millions. They belong to the trophic level of the consumers, but they influence the processes of degradation and mineralization of organic matter, mostly due to the trophic relations which they establish with fungi and bacteria. The species that feed on fungi are represented by nematodes which are furnished with a buccal stylet and, in particular, by Tylenchida. Their role in the decomposition process of litter is essentially that of rendering the nutrients contained in fungi accessible to other organisms such as bacteria. In some cases they disseminate the spores of fungi. The nematode species that feed on bacteria have no buccal stylet. Their role consists in maintaining the demographic equilibrium in the bacterial population and in favouring the spreading and the proliferation of certain species. Nematodes constitute a small fraction in terms of biomass and respiration a...

A new classification of Actinolaimoidea Thorne, 1939 using a cladistic approach

The phylogeny of Actinolaimoidea is investigated using a cladistic approach. The most important diagnostic characters of genera are examined and for each of them the apomorphic and the plesiomorphic state is indicated. On the basis of the synapomorphies shared by genera a new taxonomy of the group is proposed. The whole group is lowered in rank to family status, Actinolaimidae, in the Dorylaimoidea. Within it three subfamilies are recognized: Trachypleurosinae, without onchia, with the single genus Trachypleurosum; Hexactinolaiminae, with six onchia, with the single genus Hexactinolaimus; Actinolaiminae, with four onchia, comprising all the other genera: Trachactinolaimus, Paractinolaimus, Egtitus, Westindicus, Afractinolaimus, Neoactinolaimus, Mactinolaimus, Metactinolaimus, Actinolaimus, Parastomachoglossa, Brasilaimus, Stomachoglossa, Actinca, Brittonema and Practinocephalus. The identity of Brasilaimus and its relationship with Stomachoglossa are discussed. Keys to the subfamilies and genera and a list of the nominal species of the family, with their geographical distribution, are supplied. The chorology of Actinolaimidae is discussed and related to their phylogenesis.

One new and two known species of Aporcelinus Andrássy, 2009 and a new species of Coomansinema Ahmad & Jairajpuri, 1989 (Nematoda: Dorylaimida)

Coomansinema istvani sp. n. is described from Ecuador, and is characterised by its relatively small size (L = 0.95-1.51 mm), lip region almost continuous with body profile with partly amalgamated lips, odontostyle slightly sinuate, with wide lumen, 20-27 μm long, female reproductive apparatus didelphic, vulva transverse, pre-rectum very short, mainly in female, 8-9 weakly developed, spaced, ventral pre-cloacal supplements, tail short (c′ = 0.6-1.0), tail convex-conoid in male and cupola-shaped, with a short finger-like process dorsally oriented in female. An updated list of the species of Coomansinema and a key to their identification is also provided. In addition, one new and two known species of Aporcelinus are reported. Aporcelinus altitudinalis and A. seychellensis are described on the basis of more numerous specimens and the male of A. seychellensis is described for the first time; it is similar to the female in general morphology and is characterised by a series of 7-9 spaced ventromedian supplements in addition to the cloacal pair with two supplements in the range of the spicules. Aporcelinus reyesi sp. n. is characterised by a 1.69-1.92 mm long body, lip region truncate, set off by a constriction, lips distinct with prominent papillae, odontostyle straight, with wide lumen, 29-36 μm long, female genital system didelphic-amphidelphic, uterus tripartite, containing up to five small eggs, vulva transverse, 13 male supplements, the last three in the range of the spicules. Tail 1.0-1.5 anal body diam. long, conical with acute tip, ventrally slightly convex, dorsally first convex and then concave, often appearing bent dorsad.

The genus Paradorylaimus Andrássy, 1969 (Nematoda: Dorylaimida) with description of three new species from Ecuador

Three new species of Paradorylaimus Andrássy, 1969, found in moss and litter of natural environments of Ecuador are described. P. andinus sp. n. is characterized by 1.65–2.26 mm long female body, lip region set off by a depression, odontostyle 26.5–32. 5 μm long and 3.0–4.5 μm wide; pre-rectum 1.1–2.4 anal body diameters long in female and 1.2–2.3 in male; 0–3 prevulval and 0–5 postvulval papillae; spicules 60–80 μm long; 13–14 ventral supplements; female tail elongate-filiform, 6–10 anal body diameters long; male tail short, 0.7–1 cloacal body diameters long, dorsally convex, with a marked ventral concavity and blunt terminus. P. longicaudatus sp. n. is characterized by 1.78–2.14 mm long female body, lip region slightly set off by a depression, odontostyle 30–32.5 μm long and 2.0–3.5 μm wide; pre-rectum 1.3–2.3 anal body diameters long in female and 2– 3.5 in male; paravulval papillae absent; spicules 44.5–62.5 μm long; 11–13 ventral supplements; female tail elongate-filiform, 11–16 anal body diameters long; male tail short, 0.8–0.9 cloacal body diameters long, convex conoid, with blunt terminus. P. flagellicaudatus sp. n. is characterized by 1.65–1.73 mm long female body, lip region continuous, odontostyle 19–24 μm long and 2–2.5 μm wide; pre-rectum 1.8–2.6 anal body diameters long in female and 2.4 in male; spicules 45 μm long; 10 ventral supplements; female tail elongate-filiform, 25–26 anal body diameters long; male tail short, conoid, 0.8 cloacal body diameters long. The authors support the validity of the genus Paradorylaimus, provide an updated diagnosis and furnish a compendium of the main morphometric parameters of its species and a key to them.

A New Species of Paravulvus (Nematoda: Nygolaimidae) From Italy

A new species of Nygolaimidae, Paravulvus heynsi n. sp., is described, illustrated and discussed. It is characterized by the presence of an ovoid chamber in the median section of the stoma, surrounding the cuticularized guiding sheath. The other main characters are: cardia and cardiac glands weakly developed and rather obscure, tail dorsally convex-conoid with bluntly rounded terminus. The classification of the subfamily Nygolaiminae (sensu lato) is also discussed.

Freshwater nematodes from South Africa. 8. New and known species of Actinolaimoidea

Afractinolaimus Andrassy, 1970 is regarded as valid, its diagnosis slightly emended, and the following species transferred to it: Paractlnolaimus capensis, P. minor, P. zairensis and P. magaliesmontanus. The name of the type species thus becomes A. magaliesmontanus, since it has priority and is regarded as conspecific with A. noblei, the designated type. Additional biometrical data and distribution records are presented for A. magaliesmontanus. A. zairensis is reported from South Africa. Information is given for several populations of P. microdentatus. Two new species of Neoactinolaimus are described: N. brachydorus n. sp. is characterized by an exceptionally short and stout odontostyle, and N. barbieri n. sp. is distinguished from the closely related N. vaalensis by a thicker cuticle, more prominently set-off head, corrugated vestibule, longer oesophagus and several other minor morphological differences. Egtitus Thorne, 1967 is regarded as valid, and the following combination proposed: Egtitus zealandicu...

Description of Prodorylaimus irminii sp. n. (Dorylaimida: Nematoda) from Italy and a key to the species of the genus

During a survey of free-living nematodes in the Foce del fiume Irminio nature reserve in Sicily (Italy), a new species of the genus Prodorylaimus , P. irminii sp. n., was found, which is here described and illustrated. The new species is characterised by medium-large size (L = 1.8-2.5 mm), slender body, lip region marked by a depression, lips amalgamated, prominent labial and cephalic papillae, odontostyle 19.5-25 μ m long (1.3-1.4 lip region diam.), odontophore rod-like, 30-42 μ m long, female reproductive apparatus amphidelphic, with short ovaries, long oviduct, long uterus distally provided with pars dilatata , longitudinal vulva, vagina with sclerotised pieces, male genital system diorchic, spicules 37-50.5 μ m long, 15-16 contiguous ventromedian supplements, tail relatively short, elongate conoid and gradually tapering in female while abruptly narrowing and distally filiform in male. Prodorylaimium taebekensis (Choi & Khan, 1999) comb. n. (syn. Prodorylaimus taebekensis Choi & Khan, 1999) is proposed. A diagnostic table of characters and key to the species of the genus are also provided.

Iotonchus aequatorialis sp. n. (Nematoda: Mononchida) from Ecuador with a key to the species of Iotonchus Cobb, 1916 and remarks on the identity of the genus

A new species of nematode, Iotonchus aequatorialis sp. n., found in a soil sample from Ecuador, is described and illustrated. Iotonchus aequatorialis sp. n. is a species of medium length (2.24–2.36 mm) with a large, barrel-shaped mouth cavity 57.5–65 μ m long and 32.5–38.5 μ m diam., basal dorsal tooth, didelphic female reproductive apparatus with short, symmetrical, reflexed ovaries, relatively short vagina provided with sclerotised pieces, large uterus, no sphincter between uterus and oviducts, paravulval papillae absent, a long, slender tail 8–10 times as long as the anal body diam., and a terminal spinneret. The identities of the genera Iotonchus Cobb, 1916 and Iotonchulus Andrassy, 1994 are discussed, new diagnoses of the two genera given and their species listed. A key to the species of Iotonchus is provided. Iotonchulus darreni n. comb. (= Iotonchus darreni n. syn.) is proposed.

Three new species of Etamphidelus Andrássy, 1977 (Nematoda: Alaimidae) from South Africa and Asia.

Three new species of Etamphidelus Andrassy, 1977 are described and illustrated. E. didelphus sp. n. is characterized by having didelphic female reproductive system with strongly reduced posterior branch, by slender body, high lips, wide amphidial openings and anterior excretory pore. E. pieterloofi sp. n. is characterized by slender body, high lips, small labial pits, wide amphidial openings, prodelphic gonad, sphincter between vagina and uterus, absence of males. E. vandenbergae sp. n. is characterized by high, truncate lip region, short, conoid, ventrally curved tail with terminal mucro, prodelphic female reproductive system with spermatheca and short uterus, monorchic male reproductive system with strong spicules, four supplements and large sperms. A key to the species of Etamphidelus is given.