A new species of Eutrombicula Ewing, 1938 (Trombidiformes: Trombiculidae) from the Galápagos Islands, with a checklist of Ecuadorian chiggers

Few studies have been carried out on the Ecuadorian chigger fauna. In this study, we are describing a new species of Eutrombicula from the Galápagos Islands. Also, we provide an updated checklist of Ecuadorian and Galápagos Islands chiggers, including a new host association and locality record for Eutrombicula nerudai Stekolnikov and González-Acuña.

Carios mimon (Acari: Argasidae) description of adults and redescription of larva

Carios mimon is an argasid tick common on Chiroptera, originally described from larvae collected on bats Mimon crenulatum from Bolivia and Eptesicus brasiliensis from Uruguay. Later it was also registered from Argentina and recently included among the Brazilian tick fauna. In Brazil, this species is very aggressive to man, resulting in intense inflammatory response and pain. It is known only by the larval description and its morphology resembles that from other species currently included into the genus Carios, formerly classified into the subgenus Alectorobius, genus Ornithodoros. Here we describe adults and redescribe the larva of C. mimon, based on light and scanning electron microscopy. Remarks about its morphological similarity with other species of this genus are also discussed. Molecular analysis inferred from a portion of the 16S rRNA mitochondrial gene placed C. mimon in a cluster supported by maximal bootstrap value (100%) with other argasid species (mostly bat parasites in the New World), which have been classified into either the genus Ornithodoros or Carios, depending on the Argasidae classification adopted by different authors.

Diagnoses of and illustrated key to the species of Ixodes Latreille, 1795 (Acari: Ixodidae) from Brazil

The current Brazilian Ixodes fauna is composed of the following eight species: I. amarali Fonseca, 1935; I. aragaoi Fonseca, 1935; I. auritulus Neumann, 1904; I. fuscipes Koch, 1844; I. loricatus Neumann, 1899; I. luciae Sénevet, 1940; I. paranaensis Barros-Battesti, Arzua, Pichorim & Keirans, 2003; and I. schulzei Aragão & Fonseca, 1951. Further studies are needed to establish the taxonomic status of I. serrafreirei Amorim, Gazeta, Bossi & Linhares, 2003, a recently proposed species based solely on the nymphal stage. We present an up-to-date key to adults of the currently valid Brazilian species of Ixodes based on scanning electron microscopy. The relationships between Brazilian and other Neotropical Ixodes are also discussed.

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.

Three new species of Antricola (Acari Argasidae) from Brazil, with a key to the known species in the genus

Three new species of Antricola (Acari: Argasidae) are described from adult specimens collected on bat guano in different caves in Brazil. The female of Antricola guglielmonei n. sp. is easily determined by the presence of 2 smooth, depressed areas lacking setae in the posterolateral portions of the dorsum of the idiosoma, together with the partial fusion of the tubercles in the anteromedian portion of the idiosoma. The male of this species has a small spiracular plate surrounded by a pattern of tubercles disposed concentrically in its dorsal portion. Both sexes have cervical grooves very slightly marked. Antricola delacruzi n. sp. represents the only Antricola species with the dorsum of the idiosoma devoid of tubercles in both sexes and with scarce and minute setae placed over the smooth cuticle. The female of A. inexpectata n. sp. is known only from a few specimens. In this species, lines of smooth cuticle lacking setae separate the tubercles of the dorsum. In addition, there are 3 clumps of plumose setae close to the spiracular plate, in the ventrolateral portions of the idiosoma, in 3 well-delimited regions over cuticular thickenings. These 3 species share the peculiarity of a Haller's organ with the anterior pit bearing only 7 + 2 setae. The collection of these new species in Brazilian caves greatly expands the known range of the genus. A key to the adults of all known species of the genus is provided.

Interrelationship between ectoparasites and wild rodents from Tijucas do Sul, State of Paraná, Brazil

Sixteen species of ectoparasites were collected from 50 wild rodents from August 1990 to August 1991, in an area of Araucaria augustifolia forest, in the municility of Tijucas do Sul, State of Paraná, Brazil. Ectoparasites infested 98 per cent of the rodents, with the highest indices of infestation found in the dry-cool season. Species that occurred in single or multiple infestations were recorded. Ectoparasites/host associations were significant (p<0.01) for Gigantolaelaps wolffsohni/Oryzomys nigripes, Polygenis pradoi/Oxymycteurs sp. and Amblyopinus sp./Oxymycteurs sp. The following represent new host records: Polygenis (Polygenis) tripus from Akodon serrensis and Hoplopleura sciuricola from Sciurus aestuans. New geographic records are given for two species of flea and one sucking lice.

Estudos de carrapatos e pequenos mamíferos silvestres naturalmente infectados com espiroquetas semelhantes à Borrelia, no município de Itapevi, Estado de Säo Paulo / Studies of ticks and small wild mammals infected with spirochetes likes a Borrelia, Itapevi city, Säo Paulo state, Brazil

Este estudo contribui para elucidar os aspectos de transmissäo borreliose, em um condomínio residencial no município de Itapevi, SP, onde foram registrados os primeiros casos humanos com quadro clínico e sorológico compatíveis com a doença de Lyme. Os focos naturais de espiroquetas foram estudados no período entre janeiro/1995 e junho/1996. Um total de 134 pequenos mamíferos e 88 carrapatos coletados nestes hospedeiros foram investigados. Os carrapatos adultos foram identificados como Ixodes didelphidis, Ixodes Ioricatus e Amblyomma cajennense e os estágios imaturos como Ixodes sp. Para ambos, hospedeiros e carrapatos, foi calculado o índice de densidade relativa e correlacionado com dados meteorológicos pelos coeficientes de Spearman e Pearson. Para marsupiais e carrapatos estas correlaçöes näo foram significantes. Para roedores as correlaçöes foram significantes e diretamente relacionadas às baixas temperaturas e índices pluviométricos (p<0,05). A maior freqüência de carrapatos imaturos ocorreu na estaçäo seca, principalmente em roedores; entretanto, carrapatos adultos predominaram durante a estaçäo chuvosa, ocorrendo somente em marsupiais. Sangue e órgäos dos hospedeiros e carrapatos foram inoculados em meio BSK. Foram observadas espiroquetas semelhantes à Borrelia em culturas de sangue de 13 por cento dos marsupiais da espécie Didelphis marsupialis e em 36,4 por cento dos carrapatos coletados neste hospedeiro. Espiroquetas foram também observadas em 9,7 por cento das culturas de sangue e órgäos dos roedores Akodon cursor, bolomys lasiurus e Oxymycterus hispidus e em 30,3 por cento dos carrapatos coletados nestes hospedeiros

Perfil da borreliose de Lyme no Brasil / Outline of Lyme borreliosis in Brazil

A partir de 1989, identificamos 25 pacientes com doenca de Lyme no Brasil, dos quais 15 no estagio agudo e dez na fase latente, que permitiram reforcar sua existencia, pelos seguintes motivos: 1) existencia de um perfil clinico, caracterizado por manifestacoes cutanea, gerais, articulares e raramente cardiacas; 2) demonstracao sorologica de anticorpos anti-Borrelia burgdorferi; 3) modificacao sorologica evolutiva dos casos agudos; 4) resposta boa aos antibioticos no estagio agudo e apenas satisfatoria dos casos latentes; 5) distribuicao geografica da casuistica permitiu o mapeamento das areas de risco; 6) identificacao de carrapatos Ixodideos; 7) visualizacao de microorganismos a microscopia de campo escuro, que lembram borrelias, em culturas de humanos, animais silvestres e carrapatos; 8) comprovacao da existencia de areas endemicas para borreliose de Lyme pela sorologia em caninos e bovinos