Fleas and lesions in armadillo osteoderms.

Armadillos are bitten by several species of flea. Females of the genus Tunga penetrate the epidermis and when in place are fertilised by males, after which the abdomen swells enormously to form a 'neosome'. Within the penetrans group, T. perforans, makes lesions that perforate the osteoderms within the integument to form ~3 mm diameter cavities occupied by a discoid neosome. We examined these lesions in carapace material from animals which had died in the wild to see whether we could recruit evidence as to how they may be generated, either by the insect or by the host. We studied one species without such lesions, the nine-banded armadillo Dasypus novemcinctus, and two species with, the greater hairy armadillo Chaetophractus villosus and the southern three-banded armadillo Tolypeutes matacus, both showing the characteristic 'flea bite' holes in the external surfaces of the osteoderms. Samples were studied by three-dimensional backscattered electron mode scanning electron microscopy and X-ray microtomography. Both methods showed resorption pit complexes in the external surfaces of the osteoderms characteristic of those made by osteoclasts in active bone resorption. Lesions involved both the syndesmoses (sutures) between adjacent bones and the central regions of the osteoderms. Many lesions showed extensive repair by infilling with new bone. We conclude that the T. perforans neosome creates a local host response which causes bone resorption, creating the space in which it can grow.

Helminth-fauna of Patagonian armadillos: comparative analysis of parasites geographical variation.

The similarity between parasites communities' decay with distance and its analysis may explain important ecological process such host dispersion. Patagonia is inhabited by two armadillo species, Chaetophractus villosus and Zaedyus pichiy. In this study we describe and analyze the variation on helminth fauna of these armadillos in Patagonia compared with northern localities described in previous studies. A total of 49 armadillos were collected in Patagonia. Quantitative descriptors of parasite ecology were calculated and community structure of helminths was analyzed following the central-satellite species hypothesis. The parasite richness in Patagonia decreases almost 50% in both armadillos. Zaedyus pichiy present the same central species in Patagonia as in northern localities. For C. villosus central-satellite species analysis could not be applied. The loss of some helminths in Z. pichiy could be the result of lower temperatures or the absence of intermediate arthropods hosts. But in C. villosus the absence of some helminths with Patagonian distribution could be explained by its recent dispersion in Patagonia. Trichohelix tuberculata still being the only helminth in C. villosus introduced population of Tierra del Fuego.

Effect of host and environment-related factors on fleas of the pichi, an armadillo from Argentina.

The pichi (Zaedyus pichiy; Cingulata: Chlamyphoridae) is an armadillo whose ectoparasite fauna is composed of ticks and fleas. Fleas were collected from 218 pichis in southern Mendoza, Argentina, in summer and winter of 2015 and 2016. Prevalences were analyzed and differences in the intensities of the total number of fleas related to host (age, sex, weight, size and physical condition) and environment-related (seasonality and year) factors evaluated. Phthiropsylla agenoris was the only species found. Intensities of fleas were higher in 2015, in juveniles, and in males. Individuals with poor physical condition were more parasitized than those with good or normal body condition. The main explanatory variable was sampling year. This factor was directly associated with precipitation. The extreme conditions and heavy rains during the El Niño event in 2015/2016 led to environmental changes that seem to have severely affected the life cycle of fleas.

Tungiasis in a southern tamandua (Tamandua tetradactyla) from Formosa province, Argentina.

Tunga penetrans causes tungiasis, a parasitic disease of humans and domestic animals. In this work we report the presence of tungiasis in the southern tamandua (Tamandua tetradactyla) from Formosa, Argentina. An individual of southern tamandua was found dead on the roadside and it presented lesions consisted with neosomes located on its four limbs. We identified neosomes as T. penetrans. Records of T. penetrans in wild mammals acquire relevance because monitoring wildlife could help prevent possible outbreaks of tungiasis and other zoonosis.

New records of fleas and ticks in armadillos (Xenarthra: Chlamyphoridae) br /from the Espinal and Monte ecoregions of La Pampa province, Argentina.

La Pampa province is divided into two clearly distinguishable fractions: a small northeastern humid sector corresponding to the Pampas ecoregion and a drier western sector, represented by the Monte de Llanuras y Mesetas (termed Monte region in this paper) and Espinal ecoregions (sensu Brown et al. 2006). These three ecoregions are visibly distinguishable from an edaphological and phytogeographic point of view, while the mammalian fauna composition is homogeneous. The study area was located in the central part of the province, comprising the Monte and Espinal ecoregions (Fig. 1). In that area three species of armadillos are recorded (Soibelzon et al. 2015). Two of these (Zaedyus pichiy Desmarest, 1804 and Chaetophractus villosus Desmarest, 1804) (Xenarthra: Chlamyphoridae) are the most common and widely distributed armadillos both in the province and in the country, while the third species, Chlamyphorus truncatus Harlan, 1825, has a more restricted distribution and is one of the most cryptic and least known armadillos in the country. For this reason, in our fieldwork ectoparasites were obtained only from the first two species mentioned.

Helminth fauna of the screaming hairy armadillo Chaetophractus vellerosus from Argentina: the consequence of host isolation on parasite diversity.

Chaetophractus vellerosus in Argentina has a north-west and central distribution. An isolated population is located in the east of the Buenos Aires province, separated from the population of central Argentina by about 500 km. We compared the component community of C. vellerosus between the main population in central Argentina and the isolated population, evaluating the impact of the host isolation on parasite diversity. Sixteen species of helminths were found, namely Ancylostoma caninum, Aspidodera fasciata, Aspidodera scoleciformis, Mazzia bialata, Pterygodermatites chaetophracti, Pterygodermatites argentinensis, Strongyloides sp., Trichohelix tuberculata, Cruzia tentaculata, Cyclobulura superinae, Delicata ransomi, Macielia jorgei, Moennigia celinae, Orihelia anticlava (Nematoda), Mathevotaenia sp. (Cestoda) and Travassosia sp. (Acanthocephala). Only the first 8 species, however, were present in both populations. Prevalences and intensities of the shared species were similar. The parasite community of the isolated population, however, was less rich and diverse than that of the main population. The poor parasite community in the isolated population could have several causes: the founding population was composed of few specimens that were only infected with the most prevalent parasite species and intermediate hosts for parasites with indirect cycles were absent. In addition, coexistence with another Chlamyphoridae would have contributed to maintaining a group of species that are usual in armadillos along their distribution.

Fleas (Insecta: Siphonaptera) with public health relevance in domestic pigs (Artiodactyla: Suidae) from Argentina.

The presence of fleas can have a great negative impact on the productivity and well-being of the animals, and can contribute towards propagation of causative pathogens of important diseases in animals and humans. Fleas and domestic pigs (Sus scrofa Linnaeus, 1758) are a known association. However, knowledge about fleas on pigs in Argentina is scarce. In this country, swine farming has become one of the main components of livestock production. This activity is primarily carried out by smallholder farmers, involving a potential risk to humans of acquiring pathogens. Our study was developed in Buenos Aires province, Argentina, in a region where there is strong swine livestock activity. We provide the first record for Argentina of Ctenocephalides felis felis (Bouché, 1835) and Pulex irritans Linnaeus, 1758 in domestic pigs, and the first data for the country of parasitological indexes of fleas in pigs. Ctenocephalides felis felis and P. irritans cause discomfort, nuisance, allergic reactions, and anaemia, and are known as vectors of several pathogens with importance for public health. The high prevalence and abundance of C. felis felis and P. irritans observed in pigs from Azul, Buenos Aires, are significant, and the absence of them in other studied localities could correspond to environmental characteristics. This paper expands the knowledge about the flea diversity associated with S. scrofa in Argentina and contributes to the knowledge of the ecology and biology of two cosmopolitan fleas and with public health relevance. This information is important for future epidemiological studies, as well as to establish prevention and control measures where appropriate.

Tunga penetrans in Giant anteater (Myrmecophaga tridactyla) from Argentina.

Tunga penetrans (Siphonaptera, Tungidae) is a flea that infests humans and a variety of domestic and wild animals. Burrowing of the female flea under the skin causes tungiasis, a disease that manifests in skin lesions that if untreated, can progress to severe complications. In this paper, we report the first case of T. penetrans in a wild giant anteater (Myrmecophaga tridactyla) from Argentina. We describe the lesions and discuss the potential role of the giant anteater as a host or reservoir for this flea.