PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rhabditida”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMedDate not supplied

Two new species of nematodes (Rhabditida: Diplogasteridae and Rhabditidae) parasites of Gryllodes laplatae (Orthoptera: Gryllidae) in Argentina.

Cephalobium magdalensis n. sp. (Rhabditida: Diplogasteridae) found in Magdalena, Buenos Aires, and Cruznema lincolnensis n. sp. (Rhabditida: Rhabditidae) found in Lincoln, Buenos Aires, parasitizing the cricket Gryllodes laplatae (Orthoptera: Gryllidae) are described and illustrated. C. magdalensis n. sp. is characterized by having the excretory pore between the pseudobulb and the basal bulb and seven pairs of postanal papillae in the male. C. lincolnensis n. sp. can be distiguished by having meanly two pairs of preanal papillae, one pair of adanal papillae and six pairs of postanal papillae in the male.

Animals↗
PubMed2000

Two new rhabditida species (Nematoda: Rhabditidae) parasites of Cyclocephala signaticollis (Coleoptera: Scarabaeidae) in Argentina.

Two different Rhabditida species (Nematoda: Rhabditidae) Parasitorhabditis platidontus n. sp. and Cruznema campestris n. sp. are described and illustrated from the larvae of Cyclocephala signaticollis (Coleoptera: Scarabaeidae) from Buenos Aires province, Argentina. Parasitorhabditis platidontus n. sp. is characterized by having 4 odontoplates in the stoma and the vulva is at 80% of the length of the body. Cruznema campestris n. sp. can be distinguished by the presence of 4 odontoplates and the arrangement of the male genital papillae, 9 pairs, of which 4 are preanal and 5 postanal.

Animals↗
PubMed2004

Steinernema glaseri Santa Rosa strain (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora CCA Strain (Rhabditida: Heterorhabditidae) as biological control agents of Boophilus microplus (Acari: Ixodidae).

The present study was carried out to evaluate the action of Steinernema glaseri Santa Rosa strain and Heterorhabditis bacteriophora CCA strain as biological control agents of Boophilus microplus. Engorged females ticks were distributed on Petri dishes containing different concentrations of infective juvenile (IJ) nematodes (0, 375, 500, 750, 1,500, 2,500, 5,000 and 25,000). The data showed a reduction of approximately 90% in the eggs laid at a concentration of 5,000 S. glaseri IJs and approximately 80% at a concentration of 1,500 H. bacteriophora IJs. The female mortality increased linearly with the increase in S. glaseri concentrations. However, in the tests with H. bacteriophora this linearity was not observed. The effectiveness of the treatment with both species of entomopathogenic nematodes was compatible with other control methods. The results show the potential of S. glaseri and H. bacteriophora as biological control agents for the control of B. microplus under laboratory conditions.

Animals↗
PubMed1998

Buccal capsule development as a consideration for phylogenetic analysis of Rhabditida (Nemata).

Bacterial feeding nematodes in the order Rhabditida including Zeldia punctata (Cephalobidae) and Caenorhabditis elegans (Rhabditidae) differ profoundly in the buccal capsule parts and associated cells. We carried out a range of tests to determine which buccal capsule parts and cells are evolutionarily homologous between the representative species of the two families. Tests included reconstruction of the buccal capsule and procorpus with transmission electron microscopy (TEM), nuclei position and morphology using 4, 6-diamidino-2-phenylindole (DAPI) staining, and cell lineage using four dimensional (4D) microscopy. The lining of the buccal capsule of Z. punctata and additional Cephalobidae includes four sets of muscular radial cells, ma, mb, mc and md, in contrast to C. elegans and additional Rhabditidae, which has two sets of epithelial cells (e1, e3) and two sets of muscle cells (m1, m2). Cell lineage of a nematode closely related to Z. punctata, Cephalobus cubaensis, supports the hypothesis that in cephalobids the e1 and e3 cells become hypodermal cells or are programmed to die. Our findings contradict all previous hypotheses of buccal capsule homology, and suggest instead that ma and mb in Z. punctata are homologous to m1 and m2 in C. elegans respectively. We also hypothesize that ma and mb could be homologous to primary and secondary sets of stylet-protractor muscle cells in the plant parasitic Tylenchida.

Animals↗
PubMed2002

Agfa morandi sp. n. (Rhabditida, Agfidae) a parasite of Limax sp. (Gastropoda, Limacidae).

Agfa morandi sp. n. (Rhabditida, Agfidae), a parasite of Limax sp. (Gastropoda, Limacidae) from Py (Pyrenean mountains, France), is described and illustrated. The present species can be separated from the other two members of the same genus, A. flexilis (Rudolphi, 1819) Morand, 1990 and A. tauricus Korol and Spiridonov, 1991, by size measurements, number and disposition of the male's genital papillae, shape of the spicule and number of eggs in the female.

Animals↗
PubMed2005

A new entomopathogenic nematode, Steinernema robustispiculum n. sp. (Rhabditida: Steinernematidae), from Chumomray National Park in Vietnam.

Steinernema robustispiculum n. sp. (Rhabditida: Steinernematidae) was isolated from woodland in Chumomray National Park, Sason, Sathay, Kontum, Vietnam. Its morphology, morphometrics, cross-hybridisation and the ITS-rDNA sequence analysis revealed that S. robustispiculum clearly differs from other known Steinernema spp. As in the cases of S. intermedium (Poinar, 1985), S. robustispiculum has very robust spicules, but it can be distinguished by the longer tail of the infective juvenile, lower E%, shorter spicules, the shape of the spicules, the number of genital papillae in the caudal region and the presence of a mucron on the male tail. S. robustispiculum has a lateral field resembling that of S. sangi Phan, Nguyen & Moens, 2001, but can be distinguished by a higher E%, higher D%, smaller length to width ratio of the spicules and the morphology of both the spicule head (manubrium) and the dorsal lobe of the spicule. The morphometrics of infective juveniles of S. robustispiculum are similar to those of S. monticolum Stock, Choo & Kaya, 1997; these species can be distingusihed by the position of the excretory pore, the smaller length to width ratio of the spicules, and the length and morphology of the spicule head (manubrium). The phylogenetic relationships within Steinernema Travassos, 1927, including the newly sequenced Vietnamese species S. robustispiculum n. sp., S. loci Phan, Nguyen & Moens, 2001, S. thanhi Phan, Nguyen & Moens, 2001 and S. sangi, are presented based on analyses of the ITS-rDNA. The ITS RFLP profiles obtained from 17 different restriction enzymes are also presented.

Animals↗
PubMed2003

A new entomopathogenic nematode, Steinernema anatoliense n. sp. (Rhabditida: Steinernematidae), from Turkey.

A description is given of Steinernema anatoliense n. sp. (Rhabditida: Steinernematidae), an entomopathogenic nematode isolated from soil samples collected in the locality of Kars, East Anatolia, Turkey. Cross-hybridisation, morphological and molecular studies (RFLP analysis) indicated the distinctness of S. anatoliense n. sp. from other Steinernema species. Diagnostic characters include: body length of third-stage infective juvenile (507-580 microm); lateral field pattern with 6-8 longitudinal ridges; tail shape of the first generation male with a cuticular mucro; shape of the spicules and gubernaculum; and arrangement of the genital papillae. In addition, RFLP analysis of the ITS region of rDNA shows S. anatoliense n. sp. to be distinct from 50 other Steinernema species and isolates.

Animals↗
PubMed2005

Efficacy of entomopathogenic nematode Steinernema feltiae (Rhabditida: Steinernematidae) as influenced by Frankliniella occidentalis (Thysanoptera: Thripidae) developmental stage and host plant stage.

Entomopathogenic nematodes were investigated as an alternative biological control strategy for western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), in ornamental greenhouse crops, by using potted chrysanthemum as a model crop. The susceptibility of various life stages of F. occidentalis to different concentrations of the nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) was investigated in petri dish bioassays. This was followed with trials using potted chrysanthemums comparing the efficacy of nematode application to plants in vegetative (exposed habitat) versus flowering (cryptic habitat) stages. In both trials, the effect of the wetting agent Agral 90 (nonylphenoxy polyethoxyethanol), which is used in combination with the nematode spray, on F. occidentalis mortality was assessed. In petri dish trials, the prepupae and pupae were the most susceptible developmental stages of F. occidentalis to infection by S. feltiae. First and second instars were killed by very high rates of nematodes (> or =20,000 infective juveniles per milliliter), but corrected mortality was only approximately 28-37%. No significant mortality was observed for adult thrips. Results from the petri dish trials were confirmed on chrysanthemum plants. Foliar application of S. feltiae did not result in significant mortality in larvae or adults. No significant differences in efficacy were detected by application of nematodes on vegetative versus flowering chrysanthemum. Agral 90 had a significant impact on mortality on the first stage larvae and prepupae in the petri dish trials but not in the plant trials. Thrips control by S. feltiae in greenhouses may be partly or completely due to prepupal and pupal mortality.

Animals↗
PubMed1995

18S ribosomal RNA gene phylogeny for some Rhabditidae related to Caenorhabditis.

We have investigated the molecular evolution of the nucleotide sequences of 18S ribosomal RNA genes (18S rDNA) from a set of nematodes in the family Rhabditidae (Nematoda: Secernentea). Our aim was to evaluate the usefulness of this gene for molecular systematics of this family, as well as to establish phylogenetic relationships within a group that has potential for comparative studies of the relationship between development and evolution. We determined the 18S rDNA sequences of nine species of nematodes representing six genera within this family (Caenorhabditis briggsae, C. vulgaris, C. remanei, Rhabditis blumi, Rhabditis sp. br, Rhabditella axei, Pellioditis typica. Teratorhabditis palmarum, and Pelodera strongyloides dermatitica). Using hypothetical models for secondary structure as well as nucleotide similarity, these sequences were aligned with the 18S rDNA sequence published by Ellis et al. for C. elegans and with the partial sequences published by Nadler for eight ascaridoid species. We find that 18S rDNA is likely to be a useful tool to resolve relationships at the intrafamilial level. However, 18S rDNA sequences cannot be used to resolve relationships between taxa as closely related as the Caenorhabditis species. Parsimony, minimum-evolution, and maximum-likelihood methods strongly reject Andrássy's proposed phylogenetic classification based on adult morphological characters but support that of Sudhaus as one alternative of a few possible phylogenies. Distances between genera in this family are about eight times as great as distances between tetrapod classes, suggesting rapid rates of substitution, ancient divergence, or both.

Animals↗
PubMed2026

The genome sequence of a nematode, Thelazia callipaeda Railliet & Henry, 1910 (Rhabditida: Thelaziidae).

We present a genome assembly of Thelazia callipaeda (nematode; Nematoda; Chromadorea; Rhabditida; Thelaziidae). The genome sequence has a total length of 117.59 megabases. Most of the assembly (75.82%) is scaffolded into 4 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has been assembled, with a length of 13.66 kilobases.

Thelazia callipaeda; nematode; genome sequence; ch↗
PubMed2005

Integration of insect parasitic nematodes (Rhabditida steinernematidae) with insecticides for control of pest mole crickets (Orthoptera: Gryllotalpidae: Scapteriscus spp.).

To develop a successful integrated pest management program for pest mole crickets (Orthoptera: Gryllotalpidae: Scapteriscus spp.), it is important to ascertain the compatibility of infective juveniles of insect parasitic nematodes and chemical insecticides. Aqueous solutions of five pesticides (acephate, bifenthrin, deltamethrin, fipronil, and imidacloprid) used in turfgrass to control mole crickets were tested for compatibility with Steinernema scapterisci Nguyen & Smart (Rhabditida: Steinernematidae) in the laboratory. Survival of S. scapterisci was >95% in solutions of acephate, bifenthrin, and imidacloprid. Infectivity of S. scapterisci in adult Scapteriscus vicinus Scudder was >60% in acephate and bifenthrin; however, infectivity was <40% in imidacloprid. The entomopathogenic nematode was compatible with most insecticides tested without significantly reduced survival or infectivity.

Animals↗
PubMed2005

Aulacnema monodelphis n. g., n. sp. and Angiostoma coloaense n. sp. (Nematoda: Rhabditida: Angiostomatidae) from terrestrial molluscs of Vietnam.

Two species of nematodes, Angiostoma coloaense n. sp. and Aulacnema monodelphis n. g., n. sp. (Angiostomatidae: Rhabditida) are described from terrestrial molluscs of Vietnam. Both species are characterised by a long bowl-shaped buccal cavity and typically angiostomatid male bursal alae, spicules and gubernaculum. The new genus, Aulacnema n. g., is erected for the first reported monodelphic angiostomatid. Angiostoma coloaense n. sp. can be distinguished from other species of Angiostoma Dujardin, 1845 by having a buccal cavity length greater than its width and the absence of tail spikes on both males and females.

Animals↗
PubMedDate not supplied

Effect of ultraviolet- and X-irradiation on embryogenesis of the free-living nematode, Rhabditidae tokai: hatchability, morphogenesis and life span.

Ultraviolet light (UV)- and X-irradiation reduced hatchability in a strain of free-living nematodes, Rhabditidae tokai. Sensitivities of eggs to UV and X-ray varied greatly depending on the lapse of time after oviposition. It was found that the eggs at 5 h after oviposition were most sensitive as compared with the eggs at other developmental stages. X-irradiation of the eggs resulted in significant life shortening of the worms after hatching, whereas UV-irradiation had no such life-shortening effect. Microscopic observations showed that the frequency of morphological anomalies in populations of unhatched embryos also varied depending on the stage at which UV- and X-irradiation was applied. These results suggest that X-irradiation but not UV-irradiation have a serious after-effect on worms hatched from treated eggs.

Animals↗
PubMed1996

Host recognition behaviour predicts host suitability in the entomopathogenic nematode Steinernema carpocapsae (Rhabditida:Steinernematidae).

Steinernema carpocapsae (Rhabditida: Steinernematidae) host recognition behaviour was assessed and compared with 2 measures of host suitability. Previous research showed that S. carpocapsae infective juveniles respond to host cues in a hierarchical order, with attraction to Galleria mellonella volatiles being stimulated by contact with G. mellonella cuticle. We measured host recognition behaviour by calculating the percentage response of S. carpocapsae infective juveniles to volatiles produced by G. mellonella last instars after the nematodes were exposed to the cuticle of 11 candidate arthropod hosts and 2 control surfaces. Host suitability was measured by nematode-induced mortality to candidate hosts at 2 nematode doses and the level of reproduction supported by each host. The highest recognition response was scored for Agrotis ipsilon (Lepidoptera: Noctuidae). This insect also incurred nearly 100% mortality due to nematode infection and supported the highest level of reproduction. Non-insect arthropods tested (Chilopoda and Isopoda) stimulated no behavioural response and were not susceptible to nematode infection. Other insect species elicited intermediate levels of the recognition response. There were significant correlations between behavioural response and nematode-induced mortality at the lower dose. The level of reproduction supported by the candidate hosts was also correlated with S. carpocapsae behavioural response.

Animals↗
PubMed2006

Ecological characterization of Steinernema anatoliense (Rhabditida: Steinernematidae).

Our study describes the basic ecological characteristics of the entomopathogenic nematode Steinernema anatoliense including its response to temperature, moisture, and host range. The effect of temperature and soil moisture on the infection of Galleria mellonella larvae by S. anatoliense was determined. The temperature range for infectivity was greater than that for development. The optimal temperature for infection and development was 25 degrees C. Although S. anatoliense infected the hosts at 10 degrees C, no reproduction occurred at this temperature. This nematode species that was isolated from a cold region of Turkey exhibited warm-adapted temperature characteristics. Optimum water content of the soil for S. anatoliense to infect the host was 10%.

Animals↗
PubMed2003

Interactions of two idiobiont parasitoids (Hymenoptera: Ichneumonidae) of codling moth (Lepidoptera: Tortricidae) with the entomopathogenic nematode Steinernema carpocapsae (Rhabditida: Steinernematidae).

Simultaneous use of parasitoids and entomopathogenic nematodes for codling moth (CM) control could produce an antagonistic interaction between the two groups resulting in death of the parasitoid larvae. Two ectoparasitic ichneumonid species, Mastrus ridibundus and Liotryphon caudatus, imported for classical biological control of cocooned CM larvae were studied regarding their interactions with Steinernema carpocapsae. Exposure of M. ridibundus and L. caudatus developing larvae to infective juveniles (IJs) of S. carpocapsae (10 IJs/cm2; approximately LC(80-90) for CM larvae) within CM cocoons resulted in 70.7 and 85.2% mortality, respectively. However, diapausing full grown parasitoid larvae were almost completely protected from nematode penetration within their own tightly woven cocoons. M. ridibundus and L. caudatus females were able to detect and avoid ovipositing on nematode-infected cocooned CM moth larvae as early as 12h after treatment of the host with IJs. When given the choice between cardboard substrates containing untreated cocooned CM larvae and those treated with an approximate LC95 of S. carpocapsae IJs (25 IJs/cm2) 12, 24, or 48h earlier, ovipositing parasitoids demonstrated a significant preference for untreated larvae. The ability of these parasitoids to avoid nematode-treated larvae and to seek out and kill cocooned CM larvae that survive nematode treatments enhances the complementarity of entomopathogenic nematodes and M. ridibundus and L. caudatus.

Animals↗
PubMed1995

Germination of Bacillus thuringiensis spores in bacteriophagous nematodes (Nematoda: Rhabditida).

During screening of Bacillus thuringiensis isolates for nematicidal activity it was observed that spores of B. thuringiensis germinated in the intestine of bacteriophagous nematodes in the presence of antibiotics. This phenomenon was studied more closely by scanning electron microscopy. The nematodes were fed with bacterial spore-crystal mixtures in axenic culture medium supplemented with tetracyclin and chloramphenicol. Germination of spores was rare but was more frequently observed in Panagrellus redivivus than in other nematode species investigated. Germination of spores in the nematode intestine resulted in the colonization of the entire nematode within 24 hr. Crude nematode tissue preparations supported germination and subsequent growth of B. thuringiensis spores and vegetative cells. The mechanism for the loss of antibiotic activity in the nematode intestine is unknown. Since B. thuringiensis requires a nutrient-rich environment for reproduction, e.g., a cadaver, bacteriophagous nematodes may serve as suitable hosts for B. thuringiensis.

Animals↗