Female Nematodes Research Articles

Raccoon Heartworm Causing a Leg Mass

A 29‐year‐old man from east texas presented with a 3‐month history of a large, isolated, painful subcutaneous nodule on his lower right leg. An excisional biopsy showed zones of necrosis in the epidermis, dermis, and subcutaneous adipose tissue with a neutrophilic infiltrate. The dermis showed a mixed infiltrate with necrotic debris and a non‐gravid adult female filarial nematode with a thick, multi‐layered cuticle, paired uteri, and an intestine. The histologic features were diagnostic for dirofilaria tenuis, the raccoon heartworm. Dirofilaria tenuis causes heartworm infection in raccoons and infrequently causes human disease. When humans do contract dirofilariasis, the mode of transmission is via a bite from a mosquito infected with dirofilaria larvae. Humans are a dead end host and dirofilaria cannot reproduce in humans, but they do cause various lesions at the site of the mosquito bites. We report a very rare case of human dirofilaria tenuis infection manifesting as a subcutaneous nodule. Dirofilaria tenuis infections are very rare in the U.S., and usually occur in the Southeastern U.S.

Nematicidal activity of plant essential oils and components from garlic (Allium sativum) and cinnamon (Cinnamomum verum) oils against the pine wood nematode (Bursaphelenchus xylophilus)

AbstractPlant essential oils from 43 plant species were tested for their nematicidal activities against the pine wood nematode, Bursaphelenchus xylophilus. Responses varied with plant material and concentration. Good nematicidal activity against male, female and juvenile nematodes of B. xylophilus was achieved with essential oils of Cinnamomum verum, Leptospermum petersonii, Asiasarum sieboldi, Boswellia carterii, Pimenta racemosa, Cymbopogon citratus, Mentha spicata, clove and garlic. Garlic and cinnamon oils showed the most potent nematicidal activity among the plant essential oils. Analysis by gas chromatography-mass spectrometry led to identification of three major compounds from garlic and two from cinnamon oil. These five compounds from two essential oils were tested individually for their nematicidal activities against the pine wood nematode. Responses varied with compounds and dose. LC50 values of diallyl trisulphide, diallyl disulphide and cinnamyl acetate against juvenile nematode were 2.79, 37.06 and 32.81 μl−1, respectively. The essential oils described herein merit further study as potential nematicides against the pine wood nematode.

First Report of Soybean Cyst Nematode (Heterodera glycines) on Soybean in North Dakota.

During August 2003, soybean (Glycine max) plants from Richland County, North Dakota with white-to-yellow, lemon-shaped structures on the roots were brought to the North Dakota State University Plant Diagnostic Laboratory. To confirm that the structures were females of a cyst nematode, they were crushed and observed microscopically to determine if nematode eggs and second-stage juveniles were present. Morphology of the second-stage juveniles was consistent with Heterodera glycines, the soybean cyst nematode (SCN). A survey was conducted in soybean fields in 34 km2 around the field in which the samples originated. Ten of twenty fields surveyed had visible females on the roots of plants. Symptoms observed in those fields included patches of stunted, chlorotic, and dead plants. Soil samples were collected from selected areas within eight fields, eggs were extracted using standard soil sieving techniques, and egg numbers were determined. Egg numbers ranged from 550 to 20,000 eggs per 100 cm3 of soil. SCN collected from two different fields, designated as Dwight and LaMars, were used to determine their HG Type. Standardized procedures (1) were used in a growth chamber set at 27°C with 16-h days. Pots in the test were organized in a completely randomized design with three replicates; the test was repeated over time. After 30 days, females were extracted from roots and counted, and a female index (FI) was calculated for each indicator line (1). The mean number of females on susceptible standard cv. Lee 74, was 110. The Dwight SCN population had an FI of 5.3 on plant introduction (PI) 88788, 1.5 on PI 209332, 5.8 on PI 548316 (Cloud), and 0 on all other indicator lines. The LaMars population had an FI of 1.0 on PI 88788, 3.1 on PI 548316 (Cloud), and 0 on all other indicator lines. These results indicate that both SCN populations tested are HG Type 0. To our knowledge, this is the first report of SCN on soybean in North Dakota. Because other hosts of SCN, as well as soybean, are economically important in North Dakota, such as dry edible bean (Phaseolus vulgaris) and dry pea (Pisum sativum), this disease could adversely impact several commodities throughout the state. Reference: (1) T. L. Niblack et al. J. Nematol. 34:279, 2002.

PCR-RFLP Identification of Three Major Meloidogyne Species in Korea

Partial mitochondrial DNA from single female or second stage juvenile (J2) of root-knot nematodes was amplified by PCR (polymerase chain reaction), and the further analysis by RFLP (restriction fragment length polymorphism) provided discriminatory profiles useful for three major Meloidogyne species, M. arenaria, M. incognita, and M. hapla, in Korea. The nematode DNA was extracted individually in nuclease-free water. The sizes of PCR product (1.7 kb and 500 bp) and restriction patterns obtained from single female nematodes were consistent with the results from single J2 within the same species. M. hapla was easily differentiated from the two other root-knot nematode species by the size of the PCR products. A fragment of 500 bp was generated from M. hapla, while M. arenaria, and M incognita produced an 1.7 kb fragment in PCR amplification. M. arenaria could be distinguished from M. incognita by analysis of restriction enzyme digestion with Hinf I or Alu I. Hinf I had no digestion site in mitochondrial DNA of M. arenaria; however, it generated 1.3 kb and 400 bp fragments in M. incognita. Alu I digestion resulted in 1 kb, 460 bp, and 250 bp fragments in M. arenaria, but showed different digestion patterns in M. incognita by generating 800 bp, 460 bp, 250 bp, and 150 bp fragments.

First Report of the Root-Knot Nematode Meloidogyne javanica on Buchu (Agathosma betulina) in South Africa.

Agathosma betulina, commonly known as buchu, has been used for centuries by the indigenous people of South Africa for medicinal purposes. Currently, the essential oils from buchu are used in medicine, food flavorings, and aromatic oils. Increased exploitation of natural growing buchu in the Fynbos biome and a worldwide shortage of buchu oil encouraged commercial cultivation in South Africa. The root-knot nematode (Meloidogyne spp.) is one of the most common plant-parasitic nematodes found on commercial crops grown in the Western Cape. It has also been isolated from the soil and roots of plants in the natural Fynbos vegetation (2). In June 2003, a nursery propagating buchu plants experienced problems with poor growth. Examination of the buchu roots under a stereo microscope showed extensive galling with large numbers of female root-knot nematodes with eggsacs. Nematode extractions of the soil were also done. Only second-stage juveniles of Meloidogyne spp. (311 per 250 ml of soil) were recovered. A polymerase chain reaction (PCR)-based diagnostic method (1) was used for the identification of the root-knot nematode species. Ten intact females were dissected from the roots and individually placed directly in 5 μl drops of 1× PCR reaction buffer (16 mM [NH4]2SO4, 67 mM tris-HCL, pH 8.8, 0.1% vol/vol Tween 20) ontaining 60 μg/ml of proteinase K. The tube was kept at -80°C for a minimum of 10 min. The tube was incubated at 60°C for 15 min and 5 min at 95°C. The PCR amplifications were then prepared directly in the same tube. Amplified DNA fragments were digested with HinfI and DraI. The digested DNA was loaded on a 2% agarose gel, separated by electrophoresis, and detected by ethidium bromide staining. The digested amplified DNA fragments correspond to those of Meloidogyne javanica. Morphological characteristics were used to verify the PCR-based identification of the nematode. To our knowledge, this is the first report of M. javanica causing extensive galling on the roots of Agathosma betulina. Visual damage to the roots indicates the root-knot nematode to be an important threat to the commercial cultivation of buchu.

Expanded geographical range, new host accounts, and observations of the nematode Gyrinicola batrachiensis (Oxyuroidea: Pharyngodonidae) in tadpoles.

We describe the first account of the nematode Gyrinicola batrachiensis in the gastrointestinal tracts of tadpoles of Bufo terrestris, Gastrophryne carolinensis, Hyla femoralis, H. squirella, Rana heckscheri, and R. utricularia. Infection by G. batrachiensis was also noted in tadpoles of R. catesbeiana and R. clamitans, species previously described as harboring these nematodes. These observations represent a major expansion of the known geographical range of G. batrachiensis to include the southeastern United States. In our study, female G. batrachiensis nematodes in ranid host species were didelphic, but females in B. terrestris tadpoles were monodelphic. Furthermore, only female nematodes were found in the latter host species. Such variations in nematode uterine morphology and sex ratios among these tadpole host species are in accordance with the apomictic and haplodiploid reproductive strategies previously reported for G. batrachiensis. These observations also support a generalized pattern relating G. batrachiensis reproductive modes and the life cycles of their tadpole hosts.

On New Representatives of the Helminth Fauna of Reptiles ( Testudines and Sauria) in Uzbekistan

In a survey on parasitic helminthes of reptiles comprising 8 species under the orders of Testudines and Sauria in different areas of the plain land and foothill zones of the Ferghana Valley of Uzbekistan from 1993 through 2001, 14 species of parasitic helminthes comprising 2 cestode and 12 nematode species new to the fauna of Uzbekistan were found. List of hosts by parasitic helminthes, extensiveness and intensity of the infection, the time and sites of findings of the helminthes are reported with brief descriptions and drawings of the female nematodes of Parapharhyngodon szczerbaki Radchenko et Shapiro, 1975, Mehdiella hamosa Forstner, 1960 and the male of Abbreviata schulzi Markov et Bogdanov, 1961.

Spurious genotypes in female nematodes resulting from contamination with male DNA.

Females of many invertebrates contain stored sperm or fertilized eggs or both, causing potential genotyping errors. We investigated errors caused by male DNA contamination by amplifying 5 microsatellites in DNA isolated from various tissue types in the nematode Ascaris lumbricoides. We observed additional alleles in 30/135 uterus-derived samples when compared with muscle controls, resulting in 20/135 (15%) incorrect genotypes and an underestimation of inbreeding. In contrast, we observed additional alleles in only 5/143 ovary-derived samples, resulting in 4/143 (3%) incorrect genotypes and no significant influence on inbreeding estimates. Because uterus constitutes approximately 17% of a female's organ weight, a substantial proportion of samples isolated from female tissue may contain male-derived DNA. Male contamination is easily avoided when using large nematodes such as A. lumbricoides. However, we urge caution for studies using DNA isolated from small invertebrates that store sperm or fertilized eggs or both.

Subanguina radicicola, the Root-Gall Nematode Infecting Poa annua in New Brunswick, Canada.

Poa annua frequently is found as the dominant turfgrass species on golf course putting greens grown in the range of cool-season grasses. While not intentionally established, it is an aggressive weed in stands of bentgrasses (Agrostis spp.). When significant encroachment of P. annua occurs, it often is maintained indefinitely. In May 2003, P. annua putting greens at the Riverside Country Club in Rothesay, New Brunswick, Canada showed signs of an unidentified disease. Putting greens were slow to green up and large chlorotic patches were evident across affected areas. When roots were examined, extensive galling was observed. Galls were slender and often twisted in appearance. Upon dissection of washed galls, hundreds of eggs were exuded into the surrounding water droplet, and mature male and female nematodes were observed. Further morphological examination of males, females, and juvenile nematodes demonstrated that they were Subanguina radicicola (Greef 1872) Paramanov 1967 (1,2). Each P. annua plant had an average of four galls (with a range of two to nine) primarily located within the uppermost centimeter of the soil. Of 18 P. annua putting greens, four were affected by the nematode and displayed the same damage symptoms. S. radicicola has been identified from American beachgrass in Rhode Island and from P. annua in Oregon, but to our knowledge, this is the first report of the nematode affecting P. annua on a golf course in eastern North America.

Breakdown of immunity to Nippostrongylus brasiliensis in lactating rats

The nutritional basis of breakdown of immunity to parasites may be addressed in a rodent model. We hypothesized that lactating rats would show a breakdown of immunity to Nippostrongylus brasiliensis, and that this breakdown of immunity would be sensitive to protein supply. Rats were immunized with 1600 infective N. brasiliensis larvae and subsequently mated. During lactation, these rats were offered foods with 90 (low protein; LP) or 210 (high protein, HP) g crude protein (Nx6.25)/kg and re-infected with 400, 800 or 1600 larvae on day 2 post-parturition. Immunized non-reproducing rats were offered a food containing 60 g crude protein/kg and re-infected with 1600 larvae. Seven days after secondary infection, lactating rats had more adult nematodes in their small intestine and nematode eggs in their colon contents than the non-reproducing rats. Protein supply did not affect worm or egg counts, although LP rats carried relatively more female nematodes than the HP rats. All lactating rats had lower intakes than expected from previous studies using similar nutritional protocols. This may have resulted in insufficient protein supply, even for the HP rats, and this could explain the absence of effects of protein supply on egg and worm counts. We conclude that a breakdown of immunity to N. brasiliensis can occur in lactating rats; this strongly suggests that the lactating rat is a suitable model for elucidating a possible nutritional basis of breakdown of immunity to parasites. However, sufficient protein intake must be achieved to address the hypothesis that breakdown of immunity to N. brasiliensis is sensitive to protein supply.

Desenvolvimento de Pasteuria penetrans em Meloidogyne spp. parasitando diferentes espécies vegetais

A bactéria Pasteuria penetrans é um parasita obrigatório do nematóide das galhas (Meloidogyne spp.) e produz esporos que persistem por anos no solo. A sua produção por cultivo in vitro ainda é inviável e a produção de inoculo requer o seu cultivo in vivo em nematóides parasitando plantas em vasos. Neste trabalho, buscou-se, por meio do estudo histológico de raízes, averiguar diferenças no desenvolvimento de P. penetrans em Meloidogyne spp. parasitando raízes de tomateiro (Lycopersicon esculentum), maxixe (Cucumis anguria) e camapu (Physalis angulata), e possíveis razões para estas diferenças, como forma e tamanho de células gigantes e das fêmeas do nematóide. O maxixe foi o pior dentre os hospedeiros em teste para a produção de inóculo e apresentou células gigantes anormais. A estrutura das células gigantes assim como o desenvolvimento da bactéria foram semelhantes no camapu e no tomateiro, entretanto o ciclo de vida de P. penetrans foi ligeiramente mais curto no tomateiro.

Factors influencing the effectiveness of non-pathogenic Fusarium solani strain Fs5 in the suppression of root-knot nematode in tomato

Four experiments were carried out under greenhouse conditions to evaluate the effectiveness of Fusarium solani strain Fs5 against the root-knot nematode Meloidogyne javanica. The effect of population densities of M. javanica, various application rates of F. solani, moisture regimes and levels of benzaldehyde, a volatile compound of plant origin affecting the plant-nematode-fungus interaction, were also studied. F. solani parasitized eggs and females of M. javanica and thereby reduced root-knot severity in tomato. Although the fungus was frequently isolated from root tissues, it did not produce phytotoxic symptoms; instead, there was enhanced plant growth. At higher nematode densities, inner root colonization by the fungus increased. The rates of fungal infection on M. javanica eggs and females also increased with increasing nematode densities and fungal inoculum levels. Nematode invasion and subsequent root-knot increased with increasing soil moisture, in both F. solani-treated and untreated plants. However, root-knot development was lower at all moisture regimes when F. solani was applied to the soil. Root colonization by F. solani and parasitism on female nematodes was highest at 50% moisture holding capacity (MHC) whereas egg parasitism by the fungus was greatest at 75% MHC. With increasing concentration of benzaldehyde in soil, nematode penetration and subsequent root-knot infection were progressively reduced. Root colonization by F. solani was greatest in soil treated with benzaldehyde at 2 µg g-1 of soil in the presence of M. javanica. Increasing benzaldehyde concentrations resulted in increased parasitism of M. javanica females by F. solani but in lower parasitism of the eggs. Treatments with F. solani led to better plant growth when they were combined with benzaldehyde at 2 µg g-1 of soil.

Sporamin-mediated resistance to beet cyst nematodes (Heterodera schachtii Schm.) is dependent on trypsin inhibitory activity in sugar beet (Beta vulgaris L.) hairy roots.

Sporamin, a sweet potato tuberous storage protein, is a Kunitz-type trypsin inhibitor. Its capability of conferring insect-resistance on transgenic tobacco and cauliflower has been confirmed. To test its potential as an anti-feedant for the beet cyst nematode (Heterodera schachtii Schm.), the sporamin gene SpTI-1 was introduced into sugar beet (Beta vulgaris L.) by Agrobacterium rhizogenes-mediated transformation. Twelve different hairy root clones expressing sporamin were selected for studying nematode development. Of these, 8 hairy root clones were found to show significant efficiency in inhibiting the growth and development of the female nematodes whereas 4 root clones did not show any inhibitory effects even though the SpTI-1 gene was regularly expressed in all of the tested hairy roots as revealed by northern and western analyses. Inhibition of nematode development correlated with trypsin inhibitor activity but not with the amount of sporamin expressed in hairy roots. These data demonstrate that the trypsin inhibitor activity is the critical factor for inhibiting growth and development of cyst nematodes in sugar beet hairy roots expressing the sporamin gene. Hence, the sweet potato sporamin can be used as a new and effective anti-feedant for controlling cyst nematodes offering an alternative strategy for establishing nematode resistance in crops.

Subcutaneous infection of Lagochilascaris minor in domestic cats from Uruguay

The nematode Lagochilascaris minor was collected from subcutaneous abscesses on the face and neck of three female cats aged 8 months, and 1 and 2 years. These cats were born in the Department of Maldonado, Uruguay. Female and male nematodes were 10.1–14.4 and 10.0–14.3 mm long, respectively. The lips were one dorsal lip and two subventral lips separated from the body by a deep post-labial groove, and were separated from each other by triangular interlabial projections. The width of the lips was almost equal to the width of the post-labial collar. The vulva was near the middle of the female body. The eggs were oval or spherical and measured 0.059–0.073 mm long and 0.045–0.065 mm wide. Irregular-shaped pits were on the egg surface; 20–32 pits were around the equator of the eggs. The male posterior region was ventrally curved. Each spicule was about three quarters of the ejaculator duct length. From these findings, the nematodes were identified as L. minor. We believe this is the first report of its infection in Uruguay.

First Record of Meloidogyne partityla on Pecan in Georgia.

In July 2000, tree decline was observed in a commercial pecan (Carya illinoensis (Wang.) K. Koch) orchard in Crisp County, GA. Most affected trees exhibited dead branches in the upper canopy, stunted growth, and feeder roots with small galls and associated egg masses typical of root-knot nematode infection. All declining trees that were examined had root systems infected with a Meloidogyne sp. Efforts to culture the nematode on tomato (Lycopersicon esculentum Mill. 'Rutgers') were unsuccessful. Identification of the nematode was determined by two laboratory procedures in March 2001. Female nematodes were teased from fresh pecan root galls of declining trees in Georgia, and identified by determining the esterase phenotype from replicate samples of single females compared with standard root-knot nematode species, including a population of M. partityla (3). Galled roots also were sent to New Mexico State University in Las Cruces, where mitochondrial DNA from specimens was extracted and compared with that from standard root-knot nematode species and known populations of M. partityla (2). Specimens had esterase phenotypes and DNA patterns consistent with M. partityla. Esterase phentoypes were inconsistent with M. incognita and M. arenaria, and DNA patterns were inconsistent with M. incognita, M. javanica, and M. hapla. Specimens at both locations were identified as M. partityla Kleynhans (1). To our knowledge, this is the first report of M. partityla from Georgia and the third report of this nematode outside of South Africa. The first and second report of M. partityla from pecan in the United States occurred in Texas and New Mexico in 1996 and 2001, respectively (3,4). Our inability to culture the M. partityla-GA isolate on tomato substantiates previous experience with this nematode in the United States (3) and is not surprising, since this species has a host range limited to the Juglandaceae. Furthermore, M. partityla may be endemic to North America and not South Africa. It is believed this nematode entered South Africa on pecan seedling roots imported from the United States between 1912 and 1940 (1). The unusually narrow host range may explain why M. partityla has gone unrecognized for so long in the United States compared with the more common Meloidogyne spp. (i.e., M. incognita and M. arenaria) with wider host ranges found in pecan orchards. Determining the distribution of M. partityla within the major pecan-growing regions of Georgia and throughout North America is warranted.

First Report of Meloidogyne partityla on Pecan in New Mexico.

For several years, decline was observed in mature pecan (Carya illinoensis (F.A. Wangenheim) K. Koch) trees in an orchard in Dona Ana County, New Mexico despite normal fertilization and irrigation practices. Affected trees were growing in sandy soil in two widely separated irrigation terraces and exhibited chlorosis of foliage and substantial die-back of branches in the upper canopy. Examination of feeder roots revealed the presence of numerous small galls and egg masses, with root-knot nematode females often visibly protruding from root tissue. Attempts to culture the nematode on tomato (Lycopersicon esculentum Mill. 'Rutgers') were unsuccessful. Females and egg masses were collected from fresh pecan roots and sent to the USDA Nematology Laboratory in Beltsville, MD, in October 2000, where specimens were identified as Meloidogyne partityla Kleynhans (1) based on morphological examination. This is the first report of M. partityla from New Mexico, and the second report of this nematode outside South Africa. Starr et al. (2) first reported M. partityla from pecan in the United States in 1996, after recovering the nematode from five orchards in Texas. In their study, the host range of M. partityla was limited to members of the Juglandaceae, which may explain the inability of the New Mexico population to reproduce on tomato. Additional information is needed regarding distribution of this nematode within pecan-growing regions throughout North America.

First Report of Columbia Root Knot Nematode (Meloidogyne chitwoodi) in Potato in Texas.

Columbia root-knot nematode, Meloidogyne chitwoodi Golden et al. (1) was identified from potatoes, Solanum tuberosum L., collected from Dallam County, Texas in October 2000. Seed potatoes are the most likely source for this introduction. This nematode is currently found infecting potatoes grown in California, Colorado, Idaho, New Mexico, Nevada, Oregon, Utah, and Washington. Some countries prohibit import of both seed and table stock potatoes originating in states known to harbor M. chitwoodi. Lesions on the potatoes had discrete brown coloration with white central spots in the outer 1 cm of the tuber flesh. Female nematode densities averaged 3 per square centimeter of a potato section beneath the lesions. Nematodes were morphologically identified as M. chitwoodi based on the perineal pattern of mature females and the tail shape of juveniles per Golden et al. (1). Using polymerase chain reaction-RFLP of the rDNA ITS1 region and the mtDNA COII-16S rRNA region (2), individual juveniles were identified as M. chitwoodi based on their restriction fragment patterns. This is the first report of Columbia root-knot nematode infecting potatoes in Texas. The distribution of this nematode in potato fields throughout central United States should be determined.

Molecular-genetic characterisation of a new nematode resistance gene in wheat

Bread wheat lines introgressed with Aegilops ventricosa chromosomes were evaluated for their resistance to the Australian cereal cyst nematode (CCN, Heterodera avenae) pathotype Ha13. Higher levels of resistance relative to the phenotype of the Cre1 CCN resistance gene in wheat were found in the donor Ae. ventricosa parental lines and chromosome-5Nv substitution or addition lines. The newly identified resistance to pathotype Ha13 on chromosome 5Nv, designated, Cre6, was shown to be independent of the Ae. ventricosa-derived Cre2 gene, effective against several European pathotypes. Another Ae. ventricosa derived gene, Cre5, showed partial resistance to pathotype Ha13. Inhibition of Ha13 female nematode reproduction was ranked in the order Cre6 >Cre1 >CreF≥Cre5. Cre6 was inherited as a single dominant locus. Gene sequences encoding nucleotide-binding sites and leucine-rich repeats (NBS-LRR) from the Cre3 CCN-pathotype Ha13 resistance locus were used as probes to isolate related sequences from one of the donor Ae. ventricosa parents. Related sequences from Ae. ventricosa (71–73% similarity at the amino-acid level to the Cre3-derived sequences) of chromosome 5Nv origin were identified and served as diagnostic molecular markers for the presence of 5Nv. CCN-susceptible plants, found as variants in some of the purported chromosome 5Nv lines, were also found to be missing the diagnostic 5Nv RFLP markers assayed by the NBS-LRR probe. An alloplasmic chromosome-5Nv addition line with Ae. ventricosa cytoplasm in the wheat cultivar, Moisson, background was particularly variable, with 43% CCN-susceptible plants and a corresponding loss of the diagnostic chromosome-5 molecular markers.

Identification by polymerase chain reaction (PCR) of Marshallagia marshalli and Ostertagia gruehneri from Svalbard reindeer

A polymerase chain reaction (PCR) assay to identify two common abomasal nematodes Marshallagia marshalli and Ostertagia gruehneri of Svalbard reindeer was developed. Species-specific PCR primers were designed from internal transcribed spacer (ITS)-2 sequences of rDNA and validated using morphologically identified adult male and female nematodes. Using the species-specific primers, a 110 bp fragment was amplified from M. marshalli and its minor morph Marshallagia occidentalis and a 149 bp fragment was amplified from Ostertagia gruehneri and its minor morph Ostertagia arctica. No PCR products were amplified from the third rare species, Teladorsagia circumcincta, or DNA from the reindeer host. The assay provides a useful tool to estimate species composition for both sexes in this nematode community.

Systematic status of Laurotravassoxyuris bravoae Osorio-Sarabia, 1984 (Nematoda: Pharyngodonidae) [= Atractis bravoae (Osorio-Sarabia, 1984) n. comb.: Cosmocercidae

Re-examination of type-specimens of the nematode Laurotravassoxyuris bravoae Osorio-Sarabia, 1984, originating from the type-host, Cichlasoma istlanum Jordan et Snyder, from Mexico, has shown that these do not belong to Oxyuroidea Cobbold, 1864; in fact, the specimens included in the type-series of L. bravoae belong to two different families of the Cosmocercoidea Railliet, 1916: the Atractidae Railliet, 1917 and the Cosmocercidae Railliet, 1916. Both forms are described. Since the holotype of L. bravoae belongs to the former family, this species is transferred to Atractis Dujardin, 1845 as A. bravoae (Osorio-Sarabia, 1984) n. comb., whereas the female nematodes, belonging to the latter family, cannot be explicitly assigned to a genus or a species (although they might be conspecific with Raillietnema kritscheri Moravec, Salgado-Maldonado & Pineda-López, 1993). A. bravoae is the first species of Atractis reported from fishes; its morphology differs distinctly from that in other congeners.