Juliana Notarnicola

Arthropod and filarioid parasites associated with wild rodents in the northeast marshes of Buenos Aires, Argentina.

During 1995, 16 species of arthropods and 2 species of filarioids, totaling 1 287 specimens were collected from 64 wild rodents captured in the Hudson Natural Reserve, Buenos Aires, Argentina. Infestation parameters and indexes were analyzed. Host specific richness was S = 6, diversity H = 1.48, and relative density RDI = 40%. High values of parasite species richness and diversity were found on Oligoryzomys delticola (S = 9; H = 1.40), Oxymycterus rufus (S = 9; H = 1.37), and Oligoryzomys flavescens (S = 9; H = 1.28), followed by Scapteromys aquaticus (S = 6; H = 0.17), and Akodon azarae (S = 4; H = 1.20). Deltamys kempi was infested only by Androlaelaps rotundus. O. delticola and O. flavescens showed the highest similarity index (O = 74.19%), followed by O. flavescens with S. aquaticus, as a result of historical processes and shared microhabitats. Considering arthropods-filarioids associations, significant affinity was observed in Litomosoides bonaerensis with Hoplopleura travassosi, Laelaps paulistanensis, and Gigantolaelaps wolffsohni.

TWO NEW SPECIES OF LITOMOSOIDES (NEMATODA: FILARIOIDEA) IN SIGMODONTINES (RODENTIA: MURIDAE) FROM RIO DE LA PLATA MARSHLAND, ARGENTINA

Two new species of coelomic filarioid belonging to Litomosoides are described from sigmodontine murids from the Rio de La Plata marshland, Argentina. Litomosoides bonaerensis n. sp., a parasite of Oligoryzomys delticola, belongs to the carinii group and is close to L. silvai, which differs by the head and tail papillae, buccal capsule and cavity, area rugosa, and morphology of the microfilaria. Litomosoides oxymycteri n. sp., from Oxymycterus rufus, belongs to the sigmodontis group. Differential diagnosis is based on the morphology of the buccal capsule, the head and tail papillae, and microfilaria. The ectoparasitic gamasid Ornithonyssus bacoti, in which several Litomosoides species develop, has been recovered from sigmodontines trapped in the study.

A NEW SPECIES OF TRICHURIS (NEMATODA: TRICHURIDAE) FROM PHYLLOTINI RODENTS IN ARGENTINA

A new species of Trichuris is described. Trichuris pardinasi n. sp. was recovered from Phyllotis xanthopygus Waterhouse (Rodentia: Muridae: Phyllotini) in Sierra de la Ventana, Buenos Aires Province, and Pampa de Achala, Córdoba Province (Argentina). This is the first record of Trichuris parasitizing Phyllotini rodents. The new species can be differentiated from the other 10 species parasitizing rodents from South America by the absence of the spicular tube, spicular sheath with spines uniformly distributed, the length of spicule, the J-shaped proximal cloacal tube, and the nonprotrusive vulva. Also, a description of the bacillary band is provided. The present and the future findings of shared parasite fauna from both populations of P. xanthopygus in these disjunct areas will support the hypothesis of a continuous distribution of this host species at a past time.

A NEW SPECIES OF DIPETALONEMA (FILARIOIDEA: ONCHOCERCIDAE) FROM ATELES CHAMEK FROM THE BENI OF BOLIVIA

We describe a new species of Dipetalonema occurring in the body cavity of Ateles chamek (Humboldt, 1812) from north-central Bolivia. Morphologic characters serving to separate Dipetalonema yatesi n. sp. from known forms include a vagina vera with a simple tube and thin walls and a left spicule, which possesses a handle shorter than the lamina (ratio 2.7); the latter displays an anterior membranous alae similar in length to the terminal flagellum, a distal extremity of the left spicule within a simple hook and a membrane, phasmids at the basis of the lappets, and heterogeneous muscles occupying the whole cavity. Dipetalonema yatesi n. sp. can be separated from Dipetalonema robini, Dipetalonema gracile, and Dipetalonema graciliformis, between other characters, in having a simple vagina vera instead of a sinuous one, and from Dipetalonema caudispina and Dipetalonema freitasi in having the lamina of the left spicule divided in a membranous alae and a terminal flagellum.

A NEW SPECIES, LITOMOSOIDES ODILAE N. SP. (NEMATODA: ONCHOCERCIDAE) FROM OLIGORYZOMYS NIGRIPES (RODENTIA: MURIDAE) IN THE RAINFOREST OF MISIONES, ARGENTINA

A new species of Litomosoides was collected from the abdominal cavity of Oligoryzomys nigripes (Rodentia: Muridae) in a semideciduous secondary rainforest of Misiones, Argentina. Litomosoides odilae n. sp. belongs to the carinii group and is characterized by the amphids displaced dorsally; buccal capsule with an anterior segment transparent and an annular asymmetrical thickening; esophagus divided, with the posterior glandular portion slightly wider than the muscular; male cloacal aperture strongly protruded; and microfilaria sheathed with an attenuated tail. The morphology of the new species, which is similar to that of L. petteri, a parasite of marsupials in Brazil, suggests that host-switching events may have occurred in the diversification of this genus.

Litomosoides (Nemata: Filarioidea) of Bats from Bolivia with Records for Three Known Species and the Description of a New Species

Abstract Herein, we describe Litomosoides salazari n. sp. collected from the body cavity of the yellow bat, Lasiurus ega, from Bolivia. This new species of filarioid nematode is most closely related to the carinii group and is characterized by its relatively small size with the vulva located slightly posterior to the esophago-intestinal junction; an arrow-shaped buccal capsule; and a short, rounded tail. New host and locality records for both Litomosoides hamletti and L. chandleri in phyllostomid bats, and L. brasiliensis occurring in both phyllostomid and vespertilionid bats, are provided. The morphological variability of the specimens is documented by providing comparative measurements of 3 known species. Litomosoides brasiliensis occurs in 6 species of bats from Bolivia and was the most common species of filarioid nematode encountered. All 4 species of nematodes, including the new species, were found in sympatry at Chijchijpa, a locality in the Yungas of Bolivia.

Redescriptions of the Nematodes Litomosoides patersoni (Mazza, 1928) (Onchocercidae) and Stilestrongylus stilesi Freitas, Lent, And Almeida, 1937 (Heligmonellidae) Parasites of Holochilus chacarius (Rodentia, Cricetidae) From Salta, Argentina

Abstract Two nematode species are redescribed from the type host species Holochilus chacarius Thomas (Rodentia, Cricetidae, Sigmodontinae) and from the type locality of 1 of them, i.e., Ingenio San Martín de Tabacal, Salta Province, Argentina. Rodents were deposited at the Colección Mamíferos Lillo, Tucumán, Argentina. Litomosoides patersoni (Mazza, 1928) (Onchocercidae) possesses a buccal capsule with irregular external walls, a buccal cavity smooth, becoming thinner near the oral opening, a complete set of head papillae, 3–6 pairs of cloacal papillae, and the “sigmodontis” type of spicules. Filarioids were found in 3 of 17 examined hosts. Stilestrongylus stilesi Freitas, Lent, and Almeida, 1937 (Heligmonellidae), whose description was based on male specimens, was found in all 17 of the examined hosts. Here, we describe the female and the synlophe of both sexes. Females are characterized by a short uterus with less than 25 eggs, short ovejector, short and conical tail, and the posterior extremity strongly invaginated in a cuticular expansion usually harboring 1 to several eggs. The synlophe is characterized by 29–31 sub-equal cuticular ridges at the mid-body, with single (in males) or double (in females) axis of orientation of the ridges. The present work validates and enlarges the original descriptions of both species and assigns the specimens from L. patersoni, recovered from the type locality and the type host species, as neotypes.

Parasite community (Arthropods and Filarioids) associated with wild rodents from the marshes of La Plata River, Argentina

Abstract We investigated the parasite community (arthropods and filarioids) associated with wild rodents from a marshy area in Buenos Aires province, Argentina. During 1995 and 1996, 105 sigmodontine rodents were trapped in The Reserva Selva Marginal de Punta Lara and in La Balandra (Argentina). Six sigmodontine species with a relative density (RDI) of 11.1% were trapped. A total of 3,371 specimens from 16 species of arthropods and 2 species of filarioids were collected. The values of parasite species richness (S) and prevalence (P) were as follows: from Scapteromys aquaticus S = 9; P = 96%, from Oligoryzomys spp. S = 8; P = 100%, from Oxymycterus rufus S = 8; P = 93%, and from Akodon azarae S = 6; P = 93%. The single Deltamys kempi captured was not parasitized. Parasite communities of S. aquaticus and Ox. rufus showed the highest similarity resulting from their overlapped microhabitats, not only when presence/absence of species was considered (Sorensons index; Css = 82%), but also when the proportion of every species was taken into account (Piankas index; O = 26.67). The 2 species of filarioids collected were restricted to Oligoryzomys spp. and Ox. rufus. The absence of lice and filarioids from Ox. rufus from La Balandra suggests an isolation of this host population from the northern localities. Considering arthropod–filarioid associations, a significant affinity was observed from Ox. rufus from Punta Lara, between Litomosoides oxymycteri and the mite Ornithonyssus bacoti. Scapteromys aquaticus and Ak. azarae may not be susceptible to filarioids; although Or. bacoti were recovered from both.

A NEW SPECIES OF CYCLOBULURA (NEMATODA: SUBULURIDAE) FROM ZAEDYUS PICHIY AND CHAETOPHRACTUS VELLEROSUS (XENARTHRA: DASYPODIDAE) IN ARGENTINA

Abstract Cyclobulura superinae n. sp. collected from Zaedyus pichiy and Chaetophractus vellerosus is herein described as the second species in Cyclobulura Quentin, 1977, and the first subulurid in armadillos. The species is unique in the spur-like structures present at the tip of both spicules, yet they conform to the description of Cyclobulura in the structure of the buccal parts. Specimens of the new species show longer chordal lobes and more conspicuous radial lobes and are smaller than specimens of C. lainsoni. In addition, males of C. superinae exhibit a spur-like process in the distal end of the spicules and a shorter tail (170 vs. 300 µm) with no spine. Finally, the eggs of C. superinae are smaller (60–89 × 45–71 vs. 95–100 × 80–85). To our knowledge, the new species is the first subulurid nematode found in an armadillo.

A New Species of Molinema (Nematoda: Onchocercidae) in Bolivian Rodents and Emended Description of Litomosoides esslingeri Bain, Petit, and Diagne, 1989

Abstract: We report the distribution of 2 species of filarioid nematodes occurring in different hosts in the central region of South America. Molinema boliviensis n. sp. was recorded as a parasite of sigmodontine and echymyid rodents in Bolivia, and Litomosoides esslingeri was recorded in sigmodontine and ctenomyid rodents from Bolivia and Argentina. Molinema boliviensis n. sp. shares several similarities with other species reported in spiny rats; however, it can be easily differentiated by the presence of a flat anterior end, gradually tapering lappets and a tubercle present in posterior end, a short, uniform buccal capsule, an oval-shaped vagina vera, and a ratio of spicules of 1:1.44. An account for the morphological variability of L. esslingeri is presented that allows the identification of the buccal capsule, the tail tip in females, and the shape of spicules as reliable diagnostic traits. A complete set of head papillae is also described. The finding of these parasites in phylogenetically unrelated hosts suggests that host capture may be a frequent phenomenon in these filarioids. Researchers should focus efforts in surveying mammals within the same ecological guild to understand the distribution and host specificity of these nematodes.