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).

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.

The efficiency of extracts of Dahlstedtia pentaphylla (Leguminosae, Papilionoidae, Millettiedae) on Boophilus microplus (Canestrini, 1887) in artificially infested bovines

Tests were conducted to assess the efficiency of the roots of Dahlstedtia pentaphylla (Taub.) Burk. (Leguminosae, Papilionoideae, Millettiae) plant against infestations of Boophilus microplus (Canestrini, 1887). These tests were performed on 30 bovine animals in the Paraíba Valley, State of São Paulo, Brazil, divided into three groups (control, extract diluted at 1:10 mL and extract diluted at 1:20 mL), after artificial infestation with some 4000 larvae/animal on days -21, -14, -7, -1, 0, 7 and 14. The extract of D. pentaphylla was obtained by dehydration, spraying and extraction in absolute ethanol, at a proportion of one part of root powder to three parts of ethanol, this being taken as standard (100%). This standard extract was then diluted in water at one part of extract to 10 and 20, for spraying on the bovines. The best result obtained (an efficiency rate of 76.10%) was seen 3 days after the application of the extract at a concentration of 1:10 mL. The extract showed no effect in inhibition of the laying or hatching of larvae on engorged females, these being collected from the bovines after treatment, and kept in the laboratory.

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

Hantaviruses are the etiological agents of the Hantavirus Cardio-Pulmonary Syndrome, a serious rodent-borne disease in Brazil. In order to investigate the occurrence of hantavirus infection in wild rodents, a survey was conducted in three different suburban areas of the municipality of Pedreira, State of São Paulo, Brazil. Of the 145 wild animals captured belonging to 12 different species identified by morphology and karyological analysis, 107 were rodents of the following species: Akodon montensis, Bolomys lasiurus, Calomys tener, Oligoryzomys nigripes, Oligoryzomys flavescens, and Myocastor coypus. Blood samples from these rodents were assayed for the presence of antibodies against hantavirus by IgG ELISA using Andes recombinant nucleocapsid antigen. Antibody reactive to Andes virus was found in two different species, O. nigripes and O. flavescens. These results indicate a potential risk for hantavirus transmission to humans in this area, where reservoir rodents are present in peridomestic settings.