New species of Hassalstrongylus (Trichostrongyloidea: Heligmonellidae) in the large-headed rice rat Hylaeamys seuanezi, in the Atlantic Forest of northeast Brazil.

A new species of Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., is described from specimens collected from the small intestine of the rodent Hylaeamys seuanezi in the Atlantic Forest of northeastern Brazil (Igrapiúna, state of Bahia). The genus Hassalstrongylus includes 17 species, which parasitize rodents occurring in the Neotropical and Nearctic regions. It differs from the genus Stilestrongylus through its smaller number of ridges in the synlophe and through the size of the genital cone. The main taxonomic characteristics of this new species are the subsymmetrical caudal bursa of type 2-2-1, ray 8 branching out at the base of the dorsal trunk, right lobe smaller than the left, and rays 4 and 5 of robust nature. In addition, the ornamental ray 5 and the robustness of ray 4 on the male caudal bursa, along with the modification of the ridges of the posterior end of the female, allow us to consider the specimens found to be a new species.

Morphological and Molecular Data Reveal Two New Species of Viannaia (Nematoda: Viannaiidae), Parasitizing Opossums (Mammalia: Didelphidae) in Mexico.

Two new species of Viannaia from the intestine of the North American opossums, Didelphis virginiana (Virginia opossum), and Philander opossum (gray four-eyed opossum), are described based on morphological and molecular data, through an integrative taxonomic approach. Maximum likelihood and Bayesian inference analyses for each dataset and the concatenated dataset were performed using a mitochondrial cytochrome c oxidase subunit 1 (COI) gene, and the nuclear ribosomal internal transcribed spacer region (ITS1-5.8S-ITS2). The phylogenetic analyses revealed 2 new species that occur in Mexico, one from the western state of Colima and another from the southern state of Chiapas. Our phylogenetic trees for both molecular markers and concatenated datasets yielded similar topologies with high bootstrap values and posterior probabilities. Viannaia is recovered as a monophyletic group, but the family Viannaiidae appears as non-monophyletic, due to the position of Travassostrongylus scheibelorum, similar to previous studies. Finally, the morphology of Viannaia and Hoineffia is discussed.

New species of Hassalstrongylus (Trichostrongyloidea: Heligmonellidae) in the large-headed rice rat Hylaeamys seuanezi, in the Atlantic Forest of northeast Brazil / Nova espécie de Hassalstrongylus (Trichostrongyloidea: Heligmonellidae) no roedor Hylaeamys seuanezi, na Mata Atlântica do nordeste do Brasil

Abstract A new species of Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., is described from specimens collected from the small intestine of the rodent Hylaeamys seuanezi in the Atlantic Forest of northeastern Brazil (Igrapiúna, state of Bahia). The genus Hassalstrongylus includes 17 species, which parasitize rodents occurring in the Neotropical and Nearctic regions. It differs from the genus Stilestrongylus through its smaller number of ridges in the synlophe and through the size of the genital cone. The main taxonomic characteristics of this new species are the subsymmetrical caudal bursa of type 2-2-1, ray 8 branching out at the base of the dorsal trunk, right lobe smaller than the left, and rays 4 and 5 of robust nature. In addition, the ornamental ray 5 and the robustness of ray 4 on the male caudal bursa, along with the modification of the ridges of the posterior end of the female, allow us to consider the specimens found to be a new species.

Resumo Uma nova espécie de Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., descrita a partir de espécimes coletados do intestino delgado do roedor Hylaeamys seuanezi na Mata Atlântica do Nordeste do Brasil (Igrapiúna, estado da Bahia). O gênero Hassalstrongylus inclui 17 espécies, que parasitam roedores que ocorrem nas regiões Neotropical e Neártica. Este difere do gênero Stilestrongylus por ter menor número de cristas na sínlofe e pelo tamanho do cone genital. As principais características taxonômicas dessa nova espécie são a bolsa caudal subsimétrica do tipo 2-2-1, raio 8, ramificando-se na base do tronco dorsal, lobo direito menor que o esquerdo e os raios 4 e 5 são robustos. Além disso, o raio 5 é ornamentado na bolsa caudal dos machos, e ocorre uma modificação nas cristas da extremidade posterior da fêmea, que permite considerar os espécimes encontrados como uma espécie nova.

Purpureocillium lilacinum and Trichoderma virens for biological control of trichostrongylid parasites of sheep: an in vitro evaluation.

The study evaluated the ovicidal activity of enzymatic extracts of Purpureocillium lilacinum and Trichoderma virens against trichostrongylid eggs from sheep. Filtered extract (FE) and macerated crude extract (MCE) were prepared from fungal cultures in minimal broth. In the experiment, 100 trichostrongylid eggs, obtained from the feces of naturally infected sheep, were exposed to fungal extracts for 24 and 48 hours/25°C. In the control group, eggs were incubated in minimal broth. The number of L1 larvae was ascertained. Each treatment consisted of four repetitions and the experiment was repeated five times. It was observed that the effect of FE and MCE of P. lilacinum and T. virens on egg hatchability differed from that of the control group. MCE of T. virens and P. lilacinum showed higher ovicidal activity than FE over both periods and at 48 hours of exposure, respectively. From the percentage reductions in hatchability of the eggs, MCE was shown to be superior to FE for both fungi. This study demonstrated the ovicidal potential of these fungi against trichostrongylid eggs. However, further studies are needed in order to identify the molecules responsible for the ovicidal effects, and to evaluate the behavior of fungal extracts in biotic and abiotic interactions.

Purpureocillium lilacinum and Trichoderma virens for biological control of trichostrongylid parasites of sheep: an in vitro evaluation / Purpureocillium lilacinum e Trichoderma virens no controle biológico de tricostrongilídeos de ovinos: uma avaliação in vitro

Abstract The study evaluated the ovicidal activity of enzymatic extracts of Purpureocillium lilacinum and Trichoderma virens against trichostrongylid eggs from sheep. Filtered extract (FE) and macerated crude extract (MCE) were prepared from fungal cultures in minimal broth. In the experiment, 100 trichostrongylid eggs, obtained from the feces of naturally infected sheep, were exposed to fungal extracts for 24 and 48 hours/25°C. In the control group, eggs were incubated in minimal broth. The number of L1 larvae was ascertained. Each treatment consisted of four repetitions and the experiment was repeated five times. It was observed that the effect of FE and MCE of P. lilacinum and T. virens on egg hatchability differed from that of the control group. MCE of T. virens and P. lilacinum showed higher ovicidal activity than FE over both periods and at 48 hours of exposure, respectively. From the percentage reductions in hatchability of the eggs, MCE was shown to be superior to FE for both fungi. This study demonstrated the ovicidal potential of these fungi against trichostrongylid eggs. However, further studies are needed in order to identify the molecules responsible for the ovicidal effects, and to evaluate the behavior of fungal extracts in biotic and abiotic interactions.

Resumo O estudo avaliou a atividade ovicida de extratos enzimáticos de Purpureocillium lilacinum e Trichoderma virens sobre ovos de tricostrongilídeos de ovinos. Extrato filtrado (EF) e extrato macerado bruto (EMB) foram preparados a partir de culturas fúngicas em caldo mínimo. No ensaio experimental, 100 ovos de tricostrongilídeos, obtidos de fezes de ovinos naturalmente infectados, foram expostos durante 24 e 48 horas/25ºC aos extratos dos fungos. No grupo controle, os ovos foram incubados em caldo mínimo. O número de larvas L1 foi determinado. Cada tratamento consistiu em quatro repetições e o experimento foi repetido cinco vezes. Observou-se que o efeito ovicida do EF e EMB de P. lilacinum e T. virens diferiu do grupo controle. O EMB de T. virens e P. lilacinum evidenciou atividade ovicida superior ao EF em ambos os períodos avaliados e em 48 horas de exposição, respectivamente. O percentual de redução de eclodibilidade evidenciou que o EMB foi superior ao EF em ambos os fungos. Este estudo demonstra o potencial ovicida desses fungos sobre ovos de tricostrongilídeos. No entanto, estudos adicionais são necessários para identificar as moléculas responsáveis pelo efeito ovicida, bem como avaliar o comportamento dos extratos fúngicos em interações bióticas e abióticas.

A New Species of Bidigiticauda (Nematoda: Strongylida) from the Bat Artibeus Planirostris (Chiroptera: Phyllostomidae) in the Atlantic Forest and a Molecular Phylogeny of the Molineid Bat Parasites.

The nematode genus Bidigiticauda has 2 species (Bidigiticauda vivipara and Bidigiticauda embryophilum), which are parasites of bats from the Neotropical region. The present paper describes a new species of Bidigiticauda from a male Artibeus planirostris specimen collected in the Pratigi Environmental Protection Area in Bahia state, Brazil. The new species, Bidigiticauda serrafreirei n. sp., differs from B. embryophilum by having longer spicules, rays 5 and 6 arising from a common trunk and bifurcating in its first third, rays 3 and 4 emerging slightly separated from each other, and dorsal rays reaching the margin of the caudal bursa. The new species also differs from B. vivipara by the dorsal ray bifurcating at the extremity of the trunk. A molecular phylogenetic analysis was conducted to determine the evolutionary affinities of Bidigiticauda serrafreirei n. sp. within the Strongylida, which identified a clade that grouped Bidigiticauda with the other members of the Anoplostrongylinae. However, the molineid subfamilies did not group together, indicating that the family Molineidae is polyphyletic. Further analyses, which include additional taxa and genetic markers, should elucidate the complex relationships within the Molineidae, in particular its subfamilies and the evolution of the traits that define these groups.

Anatomopathological changes, quantification and distribution of Libyostrongylus spp. in regions of the proventriculus and ventriculus of naturally- and experimentally-infected ostriches.

Nematodes of the genus Libyostrongylus parasitize ostriches, causing high mortality rates. These nematodes are found in the proventriculus and ventriculus of ostriches, but little is known about their distribution and the possible anatomopathological changes they cause in the various regions of these organs. This paper describes the distribution and quantification of Libyostrongylus and pathological changes found in regions of the proventriculus and ventriculus of ostriches with high and low levels of both natural and experimental infection. Ostriches were necropsied and tissue samples from the distinct regions of both organs were analysed based on nematode counts and histopathology after staining with haematoxylin and eosin, Masson's trichrome or Alcian blue/PAS. The cranial and glandular regions of the proventriculus were the most parasitized. The ventriculus contained more nematodes in the caudal region. No macro- or microscopic pathological changes were observed in either of these organs of experimentally-infected birds. However, naturally-infected birds with high levels of infection presented proventriculus with macroscopic lesions and heterophilic infiltrates surrounding nematodes. In the glandular region of this organ, nematodes were located in the adenomeres of the secretory ducts, causing altered architecture and erosions and ulcerative lesions with damaged epithelium. Nematode eggs were found in the koilin layer of the middle and caudal regions of the ventriculus only of these birds. The pH of the regions assessed by Alcian blue/PAS staining changed from acidic in the proventriculus to more alkaline in the caudal region of the ventriculus. These data add knowledge to the biology of Libyostrongylus. RESEARCH HIGHLIGHTS The most parasitized areas were the cranial and glandular regions of the proventriculus. Naturally-infected birds with high levels of infection presented macro lesions in the proventriculus and damaged epithelium. Nematode eggs were found in the ventriculus. The proventriculus had an acidic pH, which turned alkaline towards the ventriculus.

First record of the nematode Libyostrongylus dentatus Hoberg, Lloyd & Omar, 1995 (Trichostrongylidae) in ostriches (Struthio camelus Linnaeus, 1758) (Struthionidae) outside the Americas.

BACKGROUND: Libyostrongylus douglassii, Libyostrongylus dentatus and Libyostrongylus magnus are nematodes that infect ostriches. The first species has been identified in ostriches from Africa, Europe, Americas and Oceania. Although the natural range of ostriches is Africa, L. dentatus was first described in birds from the USA and later identified in Brazil, where co-infections with L. douglassii have been commonly reported. Libyostrongylus magnus is known from the original description only. There are a few reports on infections with L. douglassii in ostriches from Africa and all farmed birds examined are from the southern region of the continent. The aim of this report was to verify Libyostrongylus spp. infections in wild ostriches from Ethiopia. Fecal samples from ostriches, Struthio molybdophanes, were collected and submitted to coproculture. Infective larvae were identified to the species level based on general morphology and morphometry. In addition, phylogenetic analysis of the first and second internal transcribed spacer (ITS1 and ITS2) of the nuclear ribosomal DNA was performed. RESULTS: Infective larvae from Ethiopian ostriches had the morphological characteristics of L. dentatus. Confidence interval estimate for sheath tail length from Ethiopian Libyostrongylus sp. isolates overlapped one for Brazilian L. dentatus. Neighbor-joining and Maximum Likelihood phylogenetic trees based on sequences of the ITS1 and ITS2 regions revealed that the Ethiopian samples belong to the L. dentatus species clade. Monospecific infections with L. dentatus were confirmed in Ethiopian wild ostriches, opposed to the co-infections typically found in the Americas. CONCLUSIONS: To our knowledge, this is the first record of L. dentatus from African ostriches, the region from which this parasite originated.

Effect of Gliricidia sepium leaves intake on larval establishment of Cooperia punctata in calves and bio-guided fractionation of bioactive molecules.

The aims of this study were: 1) to assess the anthelmintic effect of Gliricidia sepium on the establishment of C. punctata third-stage larvae (L3) in calves, and 2) to isolate and to elucidate an anti-exsheathment phytochemical from the plant offered during the trial. Twelve ¾ Holstein × Zebu calves were divided in two experimental groups: control (T1) and treatment (T2) (n = 6). After adaptation, each calf was infected with an oral dose of 400 C. punctata L3/Kg LW. Basal diet consisted of Digitaria decumbens hay (6.27% CP) and commercial concentrate (12% CP). In addition, during the experimental period T2 received fresh G. sepium leaves (26.88% CP) ad libitum. On day 9 post-infection, three calves per treatment were randomly selected for slaughter, and worm counts were performed. Larval establishment rates obtained were 13.44 ±â€¯0.13% and 3.1 ±â€¯1.42% for T1 and T2, respectively (P < .05). The reduction of larval establishment was 76.9%. The total length of worms recovered from the animals was also affected by the intake of G. sepium (P < .05). Phytochemicals present in G. sepium leaves offered to calves were isolated through silica gel columns and elucidated through Magnetic Nuclear Resonance (1H and 13C). Bio-guided isolation procedures lead to the elucidation of Oxytroside (Kaempferol 3-O-rhamnopyranosyl-(1 → 6)-ß-D-glucopyranoside-7-O-rhamnopyranoside), which fully inhibited the C. punctata exsheathment process (2400 µg mL-1). Gliricidia sepium represents an alternative to prevent severe C. punctata infections by reducing larval establishment in cattle.

First report of Libyostrongylus douglassii (Strongylida: Trichostrongylidae) in ostriches (Struthio camelus) from Mexico.

Nematodes of the Libyostrongylus genus are hematophagous parasites found under the ostrich's proventriculus membrane: they are frequent and can cause 50% of mortality in chicks and occasionally death in adults. With the aim of determining the presence of the Libyostrongylus genus in two private collections, one located in Ayapango, State of Mexico and the other in Amacuzac, Morelos, a total of 27 fecal samples were collected between August and December of 2016. Samples were analyzed using the flotation technique. The eggs were quantified using the McMaster technique. Positive samples were cultured to obtain infective larvae and to be identified by their morphometric characteristics. Only 18 samples collected in Ayapango were positive to Libyostrongylus douglassii. This is the first time that L. douglassii is reported in Mexico.

Pudicinae (Nematoda: Heligmonellidae) Parasitic in Endemic Chilean Rodents (Caviomorpha: Octodontidae and Abrocomidae): Description of a New Species and Emended Description of Pudica degusi (Babero and Cattan) n. comb.

We report the finding of 2 species of Pudica (Nematoda: Heligmonellidae: Pudicinae) in 2 rodents endemic to Chile, the common degu Octodon degus (Octodontidae) and the Bennett's chinchilla rat Abrocoma bennettii (Abrocomidae). Pudica degusi ( Babero and Cattan, 1975 ) n. comb., originally described as a species of Longistriata (Heligmosomidae), was found in the common degu; through the study of its synlophe, the species is reassigned to the Heligmonellidae: Pudicinae and the genus Pudica, and it is revalidated through comparison with the remaining species of the genus. Pudica cattani n. sp. is described from both O. degus and A. bennettii. It is characterized by its large body size, bursal pattern of type 1-3-1 on right lobe, 1-3-1 tending to 1-4 on left lobe, synlophe with 11 ridges including a careen, dorsal ray of the bursa dividing proximally and bursal rays 9 and 10 relatively short. Pudica degusi n. comb. and Pudica cattani n. sp. were found in the same host species but not as coparasitic in the same individuals. The common degu is confirmed as the sole and primary host of Pudica degusi n. comb. It is unlikely that it is the primary host for Pudica cattani n. sp., whose host affinities are less clear mainly due to the scarcity of data. Pudica cattani n. sp. is the first helminth reported from the Bennett's chinchilla rat. Both findings enlarge the host range of the Pudicinae to the families Octodontidae and Abrocomidae, i.e., 9 out of the 11 extant families of caviomorphs, thereby establishing the presence of this nematode subfamily as typical parasites of the Neotropical Hystricognathi.

Libyostrongylus douglassii (Strongylida: Trichostrongylidae) in ostrich (Struthio camelus) farms from Colombia.

Ostrich farming is an important livestock industry in different world regions with a diverse offer of products and services. In Colombia, as in other countries, this market led the importation of animals from countries like Canada, United States of America and South Africa for breeding objectives. With the animals, specific pathogens for these ratites could be introduced. Libyostrongylus spp. is a strongylid nematode with worldwide distribution, which can induce a severe disease and mortality in infected animals. Limited studies in Colombia have identified parasites in ostrich farming systems. The aim of this study was to identify parasites of the genus Libyostrongylus to a species level in faecal samples from ostrich farms in three departments of Colombia. Five ostrich farms from Boyacá, Meta and Tolima were sampled in 2011 and in 2013 to obtain fresh faecal samples which were further processed by flotation tests for egg visualization and faecal culture for infective larvae identification by morphological and morphometric parameters. One from the five farms, located in Meta department, was positive for strongylid eggs in both sampling periods. After faecal culture, infective larvae were identified as Libyostrongylus douglassii. These results corroborate previous records of Libyostrongylus in ostrich farms from Meta and confirms, for the first time, infection by L. douglassii in ratites from this region. Further studies must identify associated determinants for infection and its effects on the flock health and production.

Guerrerostrongylus marginalis n. sp. (Trichostrongyloidea: Heligmonellidae) from the Guianan arboreal mouse (Oecomys auyantepui) from French Guiana.

Based on the number and arrangement of cuticular ridges and configuration of the dorsal ray, nematode specimens collected from the small intestine of eight Guianan arboreal mice, Oecomys auyantepui (Rodentia: Sigmodontinae), in French Guiana are herein described and characterized. Guerrerostrongylus marginalis n. sp. (Heligmosomoidea: Heligmonellidae) shows a synlophe consisting of more than 40 ridges and a unique bursal arrangement with ray 8 (externo-dorsal) extending to the edge of the bursal margin, and appearing more prominent than the dorsal ray. This bursal arrangement is common in members of Hassalstrongylus Durette-Desset, 1971, but uncommon in the other four species in Guerrerostrongylus Sutton & Durette-Desset, 1991. The placement of the new species in Guerrerostrongylus is based on the number and nature of cuticular ridges and the ray arrangement and symmetry of the caudal bursa. Diagnostic characteristics of Guerrerostrongylus marginalis n. sp. include the length of ray 8 relative to bursal margin, the relative size of the spicules and vestibule, and the number of eggs in the uterus. We propose an amendment to the generic diagnosis of Guerrerostrongylus to modify the characters of the long rays 6 (postero-lateral), rays 8 (externo-dorsal), and dorsal ray as diagnostic, since at least ray 6 appears to be short in two different species in the genus, namely G. ulysi Digiani, Notarnicola & Navone, 2012 and G. marginalis n. sp.

A new species of Torrestrongylus (Trichostrongylidae, Anoplostrongylinae) from Macrotus waterhousii (Chiroptera: Phyllostomidae) in Central Mexico.

A new species of nematode, Torrestrongylus tetradorsalis n. sp., is described herein, based on specimens recovered from the small intestine of the leaf-nosed bat, Macrotus waterhousii, from the Biosphere Reserve "Sierra de Huautla" in the state of Morelos, Mexico. The new species is included in Torrestrongylus because it features a bursa of the type 3 - 2, a divided cephalic vesicle with an anterior half in the shape of an umbrella, and a posterior widened half. The new species can be distinguished from the only other congener T. torrei Pérez-Vigueras, 1935 by four key features: first, by the absence of cervical alae in both males and females; second, by the relatively longer second half of the cephalic cap; third, by the configuration of the dorsal ray, that does not have a medial terminal ray, and finally, by the structure of the spicules. This is the second species in the genus, previously known from bats of the families Phyllostomidae and Molossidae in Cuba, and now in Mexico.

Rediscovery and New Morphological Data on Two Hassalstrongylus (Nematoda: Heligmonellidae) Coparasitic in the Marsh Rat Holochilus chacarius (Rodentia: Cricetidae) from Argentina.

Two species of Hassalstrongylus Durette-Desset, 1971, coparasitic in Holochilus chacarius Thomas (Rodentia, Cricetidae) and not recorded since their original description in 1937, were newly found in their type host and locality. Hassalstrongylus mazzai (Freitas, Lent and Almeida, 1937) and Hassalstrongylus argentinus (Freitas, Lent and Almeida, 1937) were obtained from Ho. chacarius from 2 different populations: one from Salta Province (northwest Argentina) and another from Chaco Province (northeast Argentina). The species described as Heligmonoides mazzai Freitas, Lent and Almeida, 1937 had been transferred to Hassalstrongylus even though its synlophe had never been studied. We provide the first descriptions and illustrations of the synlophe of males and females of Hassalstrongylus mazzai and the female of H. argentinus and account for morphological and metrical variability. We confirm, through the study of the synlophe, the placement of Hassalstrongylus mazzai in the genus Hassalstrongylus and designate neotypes for the species because the type material deposited by the authors could not be found. Females of both species were morphologically very similar, and a principal components analysis (PCA) performed on some morphometrical characters showed that the body length, uterus length, and an unexpected character as the number of eggs were useful characters in the discrimination of both species.

First report of cattle farms with gastrointestinal nematodes resistant to levamisole in Mexico.

The objectives of the present study were: (1) to report the percentage of cattle farms with gastrointestinal nematodes (GINs) resistant to levamisole in Veracruz, Mexico, (2) to identify the genera of GINs involved in resistance, and (3) to identify factors associated with these resistances. The faecal egg count reduction test (McMaster technique) was used to detect the presence of resistant GINs. A questionnaire was given to owners to understand the history of anthelmintic use. The percentage of cattle farms with GINs resistant to levamisole was 36.4% (4/11). The percentage of faecal egg count reduction on resistant farms was 91%, 82%, 42% and 88%. A similar number of cattle farms (4/11) were identified as potentially having levamisole resistance. Only three farms had GIN populations susceptible to levamisole. Cooperia spp. was the genus most commonly found to be resistant, followed by Haemonchus spp., Ostertagia spp. and Oesophagostomum spp. No factors were identified that influenced the presence of GIN resistance. However, there were identified inappropriate anthelmintic practices in cattle farms that should be improved. None of the farmers weighed their animals in order to dose them correctly with anthelmintics. Six cattle farms (54.5%) applied anthelmintics to new arriving animals. This is the first report of levamisole resistant GINs in Mexico. Improving the use of anthelmintics and measures of quarantine for infected cattle will help control the spread of resistance.

Reappearance of Mecistocirrus digitatus in cattle from the Mexican tropics: prevalence, molecular, and scanning electron microscopy identification.

Mecistocirrus digitatus is a hematophagous abomasal nematode which causes significant blood and production losses in cattle. The objectives of the present study were to: (1) report the reappearance of M. digitatus in cattle from the Mexican tropics using microscopy, scanning electron microscopy (SEM), and molecular identification, and (2) determine the prevalence of M. digitatus in slaughtered adult cattle from the Mexican tropics. Gastroinestinal nematodes (GIN) were recovered from the abomasum of an 8-yr-old cow (Holstein × Zebu) previously diagnosed with Johne's disease. Of 1,254 GIN, 98.8% were identified as M. digitatus and 1.2% as Haemonchus sp. SEM was used to identify ultrastructure features of M. digitatus (oral cavity, cervical papillae, bursa, bursa lobes papillae, male spicules, anus, and female vulva). A conventional PCR method was used to corroborate the morphological findings. The prevalence of adult cattle infected with M. digitatus and Haemonchus sp., determined from 68 adult cattle from different grazing tropical herds, was 38.2% and 8.8%, respectively. Ninety-eight percent of animals infected with M. digitatus presented lesions in their abomasum such as mucosal inflammation, hemorrhage, and ulcers; some of them had necrosis. The current reappearance of M. digitatus in a Mexican herd suggests the possibility of an underestimated prevalence of this nematode amongst grazing cattle.

Population dynamics of Libyostrongylus dentatus and L. douglassii of ostriches raised in the Northern Rio de Janeiro State, Brazil.

Libyostrongylus genus contains three species of gastrointestinal nematodes that infect ostriches. Of these, only Libyostrongylus douglassii has been implicated in diseases and lower productivity. A morphological diagnosis method allowing the discrimination of infective larvae of L. douglassii and Libyostrongylus dentatus and the evaluation of eggs per gram of feces (EPG) was used to determine the population dynamics of both species from two ostrich farms located in the northern region of the state of Rio de Janeiro, Brazil. The presence of these nematodes was monitored every 15 days for two years. The average EPG was 4631 and 587 on farms 1 and 2, respectively. Overall, the highest values of EPG were associated with the rainy season on both farms. However, only on farm 1 the rainy season correlated statistically with EPG. Both species of Libyostrongylus occurred on both farms with a higher predominance (86%) of L. douglassii on farm 1, whereas the distribution of infection on farm 2 was more heterogeneous with a slight predominance of L. douglassii. The infection and the prevalence of these species may vary considerably according to the farm facilities, management adopted, and season.

Additional data on the synlophe of Stilestrongylus aculeata (Travassos, 1918) and Stilestrongylus eta (Travassos, 1937) (Heligmonellidae) parasitic in Akodon montensis (Sigmodontinae) from the Atlantic Forest.

Additional data on the synlophe and morphological measurements are provided for the heligmonellids Stilestrongylus aculeata (Travassos, 1918) and Stilestrongylus eta (Travassos, 1937), collected from Akodon montensis Thomas, 1913, of the Atlantic Forest, Rio de Janeiro, Brazil. The synlophe of S. aculeata is characterized by 19 cuticular middle body ridges in males and 24 cuticular middle body ridges in females, whereas S. eta presents 17 middle body ridges in males and 20 middle body ridges in females.

Biological control of trichostrongyles in beef cattle by the nematophagous fungus Duddingtonia flagrans in tropical southeastern Brazil.

The efficacy of a fungal formulation based on the nematophagous fungus Duddingtonia flagrans was assessed in the control of cattle trichostrongyles. Twenty male Nellore calves, six-month-old, divided in two groups (fungus-treated and control without fungus) were fed on a pasture of Brachiaria decumbens naturally infected with larvae of bovine trichostrongyles. Animals of the treated group received doses of sodium alginate mycelial pellets orally (1 g/10 kg live weight, twice a week), for 12 months. Feces samples were collected for egg count (eggs per gram of feces-EPG) and coprocultures during 12 months. There was a significant reduction in EPG (56.7%) and infective larvae (L3) in coprocultures (60.5%) for animals of the treated group in relation to the control group at the end of the study. There was a significant reduction of L3 (64.5%) in herbage samples collected up to 0-20 cm from fecal pats and 73.2% in distant samples (20-40 cm) between the fungus-treated group and the control group. The treatment with sodium alginate pellets containing the nematode trapping fungus D. flagrans reduced trichostrongylid in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode in beef cattle.