Ancylostoma (Ancylostoma) buckleyi (Nematoda: Ancylostomatidae): new wild host and distribution expansion / Ancylostoma (Ancylostoma) buckleyi (Nematoda: Ancylostomatidae): novo hospedeiro salvagem e expansão de distribuição

Abstract Here we report the occurrence of Ancylostoma (Ancylostoma) buckleyi (Le Roux and Biocca, 1957) (Nematoda: Ancylostomatidae) in the small intestine of Pampas foxes (Lycalopex gymnocercus) (Mammalia: Canidae). This fox is the most abundant native carnivore in southern South America, where it inhabits grasslands, open woodlands and areas highly modified by extensive ranching and agricultural activities. Material from 80 foxes in rural areas of southern Buenos Aires province, Argentina was examined. The intestinal tracts were carefully removed from each carcass and subsequently isolated by ligatures (pylorus and rectum). Examination of the intestinal content was performed using the sedimentation and counting technique. Four foxes (5%) were found to be parasitized with adult specimens of A. buckleyi. This is the first report of Ancylostoma (A.) buckleyi in Argentina and adds L. gymnocercus as new host of this nematode species.

Resumo O presente estudo relata a ocorrência de Ancylostoma (Ancylostoma) buckleyi (Le Roux and Biocca, 1957) (Nematoda: Ancylostomatidae) no intestino delgado do Graxaim do campo (Lycalopex gymnocercus) (Mammalia: Canidae). Essa raposa é o carnívoro nativo mais abundante no sul da América do Sul, onde habita nas pastagens, florestas abertas e áreas altamente modificadas pelas atividades pecuária extensiva e agrícola. Material de 80 raposas, em áreas rurais do sul da província de Buenos Aires, Argentina, foi examinado. Os tratos intestinais foram cuidadosamente removidos de cada carcaça e, posteriormente, isolados por ligaduras (piloro e reto). O exame do conteúdo intestinal foi realizado, utilizando-se a técnica de sedimentação e contagem. Quatro raposas (5%) foram encontradas parasitadas com espécimes adultos de A. buckleyi. O estudo registra, pela primeira vez, a ocorrência de Ancylostoma (A.) buckleyi na Argentina e adiciona L. gymnocercus como novo hospedeiro dessa espécie de nematoides.

Ixodes (Ixodes) pararicinus Keirans & Clifford, 1985 (Acari: Ixodidae) description of the immature stages, distribution, hosts and medical veterinary importance

The immature stages of the Neotropical tick Ixodes (Ixodes) pararicinus Keirans & Clifford, 1985 are describedfrom specimens in a laboratory colony initiated from engorged females collected on cattle and larvaefed on mice and chickens. The larva and nymph of I. pararicinus are described using SEM micrographs as wellas drawings for some features of the larva. Additionally, immature stages of I. pararicinus collected on wildmice and birds in Uruguay and Argentina were compared with specimens from the laboratory colony. Ataxonomic key to the nymphs of the species of the ricinus complex established in the Western Hemisphere ispresented. The distribution of I. pararicinus comprises Argentina, Colombia and Uruguay, but it is alsoprobably established in Bolivia, Brazil, Chile and Peru. Most adult ticks of this species have been found onintroduced domestic artiodactyles, although Neotropical deer species must have been the ancestral host.Larvae and nymphs of I. pararicinus have also been found on sigmodontine rodents and passeriformbirds. Although I. pararicinus is a member of the ricinus complex, which contains the main vectors ofBorrelia burgdorferi (sensu lato), there are few studies concerning its potential for pathogen transmission.