Intestinal parasites of Tolypeutes matacus, the most frequently consumed armadillo in the Chaco region.

The southern three-banded armadillo Tolypeutes matacus (Desmarest, 1804) is distributed from eastern Bolivia, south-west Brazil, the Gran Chaco of Paraguay and Argentina, and lives in areas with dry vegetation. This armadillo is one of the most frequently consumed species by people in this area. The objective of this work was test for zoonotic species among helminths in 12 intestinal tracts of T. matacus in a locality from the Argentinean Chaco (Chamical, La Rioja province). The parasites were studied with conventional parasite morphology and morphometrics, and prevalence, mean intensity and mean abundance were calculated for each species encountered. In the small intestine, seven species of nematodes and two species of cestodes were identified. In the large intestine, two species of nematodes were recorded. We did not find zoonotic species but have added new host records. This study in the Chaco region thus contributes to growing knowledge of the parasite fauna associated with armadillo species in this region.

Loss of helminth species diversity in the large hairy armadillo Chaetophractus villosus on the Tierra del Fuego Island, Argentina.

The aim of this work is to compare the taxonomic diversity of parasite species of the large hairy armadillo Chaetophractus villosus in its native range and in another recently introduced population (Tierra del Fuego island), and to evaluate whether the isolation of the latter determines a decrease in its parasitic diversity. Forty specimens from Buenos Aires and Tierra del Fuego Provinces were collected and examined for helminths. Eleven parasite species were found in the native population, and only one species was present in Tierra del Fuego (Trichohelix tuberculata). This may be explained because isolation and climatic conditions prevent encounters between potential host species and infective forms of parasites. Further sampling will be needed throughout the entire Patagonia steppe to confirm how the characteristic parasitic fauna of C. villosus behaves across the armadillo's southern distribution.

A new species of Tunga perforating the osteoderms of its armadillo host in Argentina and redescription of the male of Tunga terasma.

A new species of Tunga (Siphonaptera: Tungidae) collected from armadillos in Argentina is described. The new species is characterized by large and pigmented eyes, the presence of two bristles on antennal segment II, two bristles at the base of the maxilla, and a discoid neosome compressed anteroposteriorly. The gravid female is located in the carapace of the host, perforating the osteoderms. The new species resembles Tunga penetrans and Tunga terasma in general appearance. However, it differs by the greater anteroposterior compression of the neosome, a more angular head, and a manubrium with a pointed proximal end and convex ventral margin (the proximal end of the manubrium is rounded or slightly pointed in T. terasma, and the ventral margin is straight in both T. penetrans and T. terasma). In addition, specimens of T. penetrans have more bristles in antennal segments II and III, and lack bristles in the posterior tibia. This is the first report of a species of Tunga perforating the osteoderms of its host and thereby showing a high degree of specialization. Tunga terasma is recorded for the first time in Argentina; the male is described again and the characteristics of the species amended. This information may be useful in epidemiological studies of diseases caused by species of Tunga.

Surface ultrastructure of the eggs of Malacopsylla grossiventris and Phthiropsylla agenoris (Siphonaptera: Malacopsyllidae).

The fleas of the Malacopsyllidae are known only by their adults. In this study, we describe the eggs of Malacopsylla grossiventris and Phthiropsylla agenoris and compare their surface ultrastructure using scanning electron microscopy. Eggs of both flea species are similar in their general appearance, i.e., the presence of disks and absence of lateral aeropyles, but they differ in size, texture of the surface, and number of micropyles and aeropyles. In addition, the eggs of M. grossiventris and P. agenoris are larger (719-800 µm) than most of the flea eggs known (<600 µm), and the length/width ratio is 2.0, while it varies between 1.6 and 1.8 in other species. As opposed to other large species, malacopsyllids have expandable (telescoping) abdomens that display growth. It is possible that a clutch of eggs has more than 2 eggs. Females of M. grossiventris were observed fixed with their mouthparts to the skin of their hosts. Indeed, some of these specimens were observed copulating on the venter of their hosts. These results contribute to the knowledge about the biology of malacopsyllids.