Rhinonyssus rhinolethrum (Trouessart, 1895) (Mesostigmata: Rhinonyssidae) in Netta peposaca (Vieillot, 1816) (Anseriformes: Anatidae) from Southern Brazil.

Netta peposaca is an anatid endemic to the South American continent and Rhinonyssus rhinolethrum is a rhinonissid mite of wide geographical distribution parasitizing several species of anatids. The association between these organisms has been reported in Argentina; however, the number of birds examined and the parasite indices have not been reported. Thus, the objective of this study was to know the diversity of nasal mites associated with N. peposaca in southern of Brazil and the parasitological indices. The nasal cavities of 30 birds from two locations in Rio Grande do Sul, Brazil, were examined to collect mites. Rhinonyssus rhinolethrum occurred in 16.67% of the birds with an infection intensity of 3-24 mites/host. Infections in male and female hosts showed no significant differences. This study records for the first time R. rhinolethrum and its infection indices in N. peposaca in the southern of Brazil.

Ocorrência de ixodidae parasitos de capivara (Hydrochoerus hydrochaeris linnaeus, 1766) na estação ecológica do Taim, Rio Grande - RS, Brasil / Occurence of ixodidae parasites of capybara (Hydrochoeurus hydrochaeris linnaeus, 1766) in the ecologic area of Taim, Rio Grande - RS, Brazil

O objetivo deste trabalho foi identificar as espécies de carrapatos observadas sobre capivaras na Estação Ecológica do Taim, Rio Grande- RS, Brasil. Foram examinadas 27 capivaras encontradas mortas por atropelamento na BR 471, em seu trecho que corta a Estação, sendo cole lados 497 carrapatos das espécies Amblyomma cooperi (=A. lutzi; = A. ypisilophorum), Amblyomma triste, Amblyomma tigrinum e ninfas do gênero Amblyomma. A. cooperi representou 68,41 por cento dos carrapatos identificados, com uma freqüência de parasitismo de 92,60 por cento dos hospedeiros, enquanto A. triste representou 24,75 por cento dos carrapatos em 44,43 por cento dos hospedeiros e A. tigrinum foi coletado em 14,81 por cento dos hospedeiros, totalizando 1,21 por cento dos carrapatos. As ninfas de Amblyomma sp. foram cotetadas em 18,51 por cento dos hospedeiros apresentando um percentual de 5,63 por cento do total de carrapatos. A relação macho : fêmea apresentou valores de 2,3 : 1 e 2 : l para o A. cooperi e A. triste, respectivamente. Todos hospedeiros apresentavam-se parasitados, com uma média de 18,4 carrapatos, variando de 1 a 64 carrapatos coletados por hospedeiro.

The aim of this article was the identification ofthe tick species observed on capybara in wildlife in the Ecologic Area of Taim, Rio Grande - RS; Brazil. Twenly seven capybaras found dead by trample in the road BR 471 in the Ecologic Area, wereexamined ticks coilected of the species Amblyomma cooperi (= A. lutzi and = A. ypisilophorum), Amblyomma triste, Amblyomma tigrinum and ninphs of the Genus Amblyomma. Amblyomma cooperi represented 68.41 percent of the ticks with a frequency of parasitism of 92.60 percent of the hosts; Amblyomma triste species represented 24.75 percent of the collected ticks m 44.43 percent of the hosts; Amblyomma tigrinum species were coilected m 14.81 percent of the hosts from a total of 1.21 percent of the found ticks and, the nimphs of Amblyomma were coilected in 18.51 percent of the hosts per forming 5.63 percent of the ali ticks coilected. The relation mate .female showed values of 2.3:1 and 2:1 to A. cooperiand and A. triste, respectivety. All examined hosts were found wiih ticks, with a mean of 18.4 ticks per host.