A new isolate of Mesorhabditis monhystera (Bütschli, 1873) Dougherty, 1955 (Rhabditida: Rhabditidae): re-evaluated with molecular data and scanning electron microscopic observations.

A new isolate of Mesorhabditis monhystera (Bütschli, ) Dougherty, is described and illustrated with morphological and molecular data. The phylogenetic analysis based on the D2/D3 segment of 28S rDNA using the Bayesian inference method, revealed monophyly of the genus Mesorhabditis as the subordinate taxa clustered in one clade. The clade further divided into two subclades representing the Monhystera-group and Spiculigera-group with 100% posterior probability values. However, GenBank sequences of several species constituting the Monhystera-group, showed high similarity and very little genetic divergence (98-99%) of up to 4-5 bases. In order to ascertain the status of those isolates, detailed morphological comparison is provided along with a pictorial key. A sequence-based phylogeography of haplogroups of Mesorhabditis using the median-joining network method, was also inferred. The results suggested the need for morphological validation of a species before its sequences are deposited in GenBank.

Molecular and phenotypic characterization of two cryptic species of the predatory genus Mononchoides Rahm, 1928 (Rhabditida: Diplogastridae) and their congeneric affinities.

Based on morphometric, morphological and molecular characterization using partial small subunit 18S ribosomal DNA (rDNA) and the D2/D3 domain of large subunit 28S rDNA, we described a new species Mononchoides kanzakii collected from manure, and the known species Mononchoides composticola Steel, Moens, Scholaert, Boshoff, Houthoofd and Bert, 2011, isolated from the dung beetle Oniticellus cinctus (Fabricius, 1775). Phylogenetic trees based on the evolutionary model (GTR + I + G) were inferred by Bayesian inference algorithms. Mononchoides kanzakii sp. n. is characterized by 28-32 longitudinal ridges, discontinuous at level of stoma; amphidial apertures inconspicuous; metastegostom armed with thorn-shaped dorsal tooth; a flattened, claw-like right subventral tooth, and left subventral denticulate ridge with 12-14 fine denticles delimited by a group of five denticles in females vs. triangular, flattened right subventral tooth, 5-8 prominent denticles at left subventral sector in males; cloacal lips with a distinct rim; and gubernaculum with cuticularized, proximal and distal extensions of equal length, each constituting half of the length of the wider part of gubernaculum.

Molecular phylogeny and new insight into the stomatal complexity of Fictor platypapillata sp. n. (Diplogastridae: Nematoda) associated with Oniticellus cinctus (Coleoptera: Scarabaeidae).

The new species Fictor platypapillata was isolated from dung beetle Oniticellus cinctus (Scarabaeidae), collected from the district Balrampur, Uttar Pradesh, India. Fictor platypapillata sp. n. is described based on morphology, morphometric and molecular characterization, supplemented with scanning electron microscopy observations. The new species is characterized by two female morphs based on stomatal dimorphism: α morph with left subventral wall having 14 denticles, six low conical and eight elongated finger-like, slender denticles separated by a deep groove; inner wall of gymnostom with linearly arranged warts; ß morph with inner wall of gymnostom lacking warts; dorsal and right subventral stegostomal walls having large, slender teeth with hook-shaped apical end. Genital sensilla eight pairs with v5 pair flattened, button-shaped, located ventrally. The phylogenetic analyses revealed significant congruence, especially in the position of the subordinate taxa of genus Fictor that shows polyphyly by both Bayesian inference and minimum evolution methods. The taxonomy of the genus is updated with a valid species list along with their geographical mapping.

Description of new species of Pterygorhabditis Timm, and Aspidonema (Sachs, ) Andrássy, (Nematoda: Bunonematoidea) in aquatic habitats from India.

The paper contains descriptions of two new species of the genera Pterygorhabditis Timm, 1957 and Aspidonema (Sachs, 1949) Andrássy, 1958 belonging to the families Pterygorhabditidae Goodey 1963 and Bunonematidae Micoletzky 1922, respectively. Species were procured from fixed samples, collected earlier from aquatic habitats. Pterygorhabditis punctata n. sp. is characterized by a cuticle with flattened hexagonal blocks arranged in eight longitudinal rows in both sexes; each metastegostomal plate with a minute denticle, and males with long, slender, fused spicules and nine pairs of post-cloacal, prominently setose genital papillae. Aspidonema formosa n. sp. is the first report of the genus from India. The species is characterized by the right side provided with 35-48 pairs of warts flanking a row of smooth membranous shields and surrounded by a well-developed network and an anisomorphic metastegostom without discernible armature. Species are compared with other congeners, together with the diagnoses of amended genera, and keys to the identification of species are provided.

Impact of the nematophagous fungus Pochonia chlamydosporia on nematode and microbial populations.

The microbial and nematode populations associated with two plants (tomato and cabbage) inoculated with the nematophagous fungus, Pochonia chlamydosporia var. chlamydosporia or root knot nematode (Meloidogyne incognita), or both, were compared with those in unplanted controls. The dominant factor affecting culturable microbial populations was found to be the presence or absence of tomato plants. Generally microbial colony counts were lowest in unplanted soil, small increases were associated with cabbage and significantly greater numbers with tomato plants. Differences in microbial diversity (estimated from community profiles of carbon substrate utlisation, using Biolog) were observed between planted and unplanted soils, however, there were few differences between soils with either of the two plants. The presence of P. chlamydosporia was associated with a reduction in the numbers of plant parasitic nematodes (51%-78%) including the migratory ectoparasites, whereas free-living nematodes, culturable bacteria and bacterial populations assessed by Biolog were unaffected by the application of fungus.

Descriptions of two new species of chronogaster cobb, 1913 from India.

Two new species of Chronogaster in India were described and illustrated, based on light and scanning electron microscopy. Chronogaster neotypica n. sp. collected from a sewage slurry was characterized by a medium-sized body, a ventral tail mucro without additional spines, absence of longitudinal incisures in lateral fields, and by the presence of crystalloids in the body. Diagnostic for C. spinicauda n. sp. collected from soil around roots of mango were a medium-sized body, a tail mucro with 10 spines, and absence of lateral lines and crystalloids. Males were not found.