A Revision of Parasecia (Trombidiformes: Trombiculidae) With a Description of a New Species, a New Genus and a Key to Species.

Chiggers of the genus Parasecia Loomis parasitize birds, mammals, and reptiles in the Nearctic and Neotropical regions. In the present review, we examined 18 species previously included in the genus, 15 of them being retained in the genus Parasecia, one genus is created, Nahuacarus bulbocalcarn. gen. (Trombidiformes: Trombiculidae), and new combinations are proposed for two species: Lorillatum lasiurusn. comb. and Lorillatum orphanan. comb. (Trombidiformes: Trombiculidae). In addition, Parasecia kansasensis (Loomis) (Trombidiformes: Trombiculidae) is synonymized with Parasecia gurneyi (Ewing) (Trombidiformes: Trombiculidae), Parasecia gilbetoin. sp. (Trombidiformes: Trombiculidae) is described and new locality and host records are added for Parasecia chara (Wharton), Parasecia longicalcar (Brennan and Jones), Parasecia manueli (Brennan and Jones), and Parasecia thalurania (Brennan) (Trombidiformes: Trombiculidae).

Description of the larva of Amblyomma calcaratum Neumann, 1899 (Acari: Ixodidae) by light and scanning electron microscopy.

The larval stage of Amblyomma calcaratum Neumann is described using optical and scanning electron microscopy. Unfed larvae were obtained from a colony of A. calcaratum originating from engorged females collected on Tamandua tetradactyla in the Jaraguá Mountain (23°40'S, 45°44'W), São Paulo County, Brazil. Eleven larvae were prepared and mounted on slides and observed under a light microscope equipped with a drawing tube. Three specimens were prepared for SEM. Several morphological characters are described, including the chaetotaxy of the idiosoma, palpi, and Haller's organ, as well as morphological features of the idiosoma, gnathosoma, and legs of A. calcaratum larvae. In addition, topographical and numerical patterns of integumentary structures on the larval idiosoma are described using a recently proposed nomenclature. On the idiosoma, setaes, lyrifissures, small glands, and large wax glands were found. These structures were observed isolated or associated over the entire idiosoma, except on the scutum, which lacks large wax glands. The topographical and numerical patterns of integumentary structures of the A. calcaratum larva showed only minor differences when compared with patterns of other Amblyomma larvae; however, a few key features can be used to differentiate A. calcaratum from other members of this genus.

Description of larva of Amblyomma romitii (Acari: Ixodidae) by optical and scanning electron microscopy, including porotaxy and phylogenetic analysis.

The description of the larva of Amblyomma romitii Tonelli-Rondelli is based on optical and scanning electron microscopy. Larvae were obtained under laboratory conditions from an engorged female collected on capybara from Rurópolis municipality, State of Pará, Northern Brazil. Several characters are presented including the chaetotaxy of idiosoma, palpi and Haller's organ. The larval porotaxy (topographical and numerical patterns of integumentary structures) was presented and compared to that of the other Amblyomma spp. larvae. The mitochondrial 16S rDNA partial sequence of A. romitii generated in the present study was aligned with sequences previously determined for other Amblyomma species available in Genbank and with some species presently sequenced. The larval morphology of A. romitii and other Neotropical Amblyomma spp. larvae is discussed as well as the DNA sequence and its phylogenetic position among other species of the genus.

Molecular dissimilarities of Rhipicephalus sanguineus (Acari: Ixodidae) in Brazil and its relation with samples throughout the world: is there a geographical pattern?

In this study the genetic variability of Rhipicephalus sanguineus within Brazil and its relation with ticks of the same group from different continents was evaluated. Mitochondrial 12S and 16S rDNA fragments of R. sanguineus from seven Brazilian States were sequenced and compared to GenBank sequences of R. sanguineus and R. turanicus ticks from Africa, Asia, Europe, South America and USA. Results indicate a relatively high intra-specific variability between Brazilian samples but also a global latitude linked distribution pattern of at least two major R. sanguineus groups; one group distributed from latitude 25 degrees N to 22 degrees S including R. sanguineus from Brazil, Taiwan and Thailand and R. turanicus from Zambia and Zimbabwe, and the other group found closer to the poles, roughly above 29 degrees N and below 30 degrees S with ticks from Argentina, Uruguay, France, Oklahoma (USA), Israel and Egypt.

Topographical and numerical study of the idiosomal integumentary structures of the larva of four Neotropical species of Amblyomma Koch, 1844 (Acari: Ixodidae).

Integumentary structures of the larvae of Amblyomma longirostre (Koch, 1844), A. parvum Aragão, 1908, A. rotundatum Koch, 1844 and from three populations of A. cajennense (Fabricius, 1787) were studied using light microscopy. A new nomenclature for the localisation of the integumentary structures is proposed. Three types of integumentary structures were identified in the larval idiosoma of the four Amblyomma species: lyrifissures, small glands and large wax glands. These structures were observed isolated or associated over the entire idiosoma, except in the scutum, which lacked lyrifisures and large wax glands. Large wax glands were the most stable within and between the tick species, followed by lyrifissures and small glands. Small glands, although relatively stable, showed the highest number of numerical variations within and between the tick species. Even though there were intra-population variations in the topographical and numerical pattern of some integumentary structures of A. cajennense larvae, there was a definitive pattern for most of the specimens, as showed by the similar modal and mean numbers of integumentary structures per tick side. The patterns of lyrifissures, small glands and large wax glands showed little differences when compared between the four Amblyomma species; however, a few differences were well evident. These differences were sufficient to differentiate larvae of the four species. Thus, we expect that the study of integumentary structures on the larvae of other Amblyomma species will be useful in future taxonomic keys for the identification of Amblyomma larvae from the Neotropical region.

Description of the larva of Amblyomma longirostre (Koch,1844)(Acari: Ixodidae) by light and scanning electron microscopy.

The description of the larva of Amblyomma longirostre (Koch, 1844) is based on optical and scanning electron microscopy. Larvae (F1) were obtained under laboratory conditions from an engorged A. longirostre female, which had been collected on a Coendu prehensilis (Linnaeus) (Rodentia: Erethizontidae) from the Jaraguá Mountain, São Paulo municipality, State of São Paulo, Brazil. Several characters are presented including the chaetotaxy of idiosoma, palps and Haller's organ, campaniform sensillum on festoons and measurements. In addition, the relationship of A. longirostre larva to other Neotropical Amblyomma spp. larvae is discussed.

Redescription of larva, nymph and adults of Ixodes (I .) loricatus Neumann, 1899 (Acari: Ixodidae) based on light and scanning electron microscopy.

Ticks of the genus Ixodes are poorly known in the Neotropical zoogeographical region, from where only 45 species have been recorded. In Brazil, the genus is currently represented by eight species, four of which are known only from this country. This paper presents a redescription of all active stages in the life-cycle of I. loricatus , based on optical and scanning electron microscopy. In addition, the relationship of I. loricatus to other Neotropical Ixodes is presented and discussed.

Evidence of hantavirus infection in wild rodents captured in a rural area of the state of São Paulo, Brazil

Hantavírus é o agente etiológico da síndrome cardio-pulmonar por hantavirus (SCPH), uma importante doença transmitida por roedores no Brasil. Com o objetivo de se conhecer a ocorrência de infecção por hantavírus em pequenos roedores silvestres, uma análise sorológica foi conduzida em três diferentes áreas do subúrbio da cidade de Pedreira, São Paulo. Dos 145 animais silvestres capturados, pertecentes a 12 diferentes espécies identificadas por morfologia e por análise cariológica, 107 eram roedores das seguintes espécies: Akodon montensis, Bolomys lasiurus, Calomys tener, Oligoryzomys nigripes, Oligoryzomys flavescens, e Myocastor coypus. Amostras de sangue desses roedores foram testadas para a presença de anticorpos IgG contra o antígeno do nucleocapsídeo do vírus Andes através do teste ELISA. Reatividade sorológica ao vírus Andes foi observada em duas espécies diferentes, O. nigripes and O. flavescens. Estes resultados indicam o potencial risco de transmissão de hantaví-rus nesta região, onde roedores reservatórios freqüentemente são vistos em peridomicílio.