The occurrence and foraging behavior of the army ant Eciton vagans dubitatum in the Itirapina area, São Paulo State, Brazil (Hymenoptera, Formicidae)

This paper discusses the occurrence of the army ant Eciton vagans dubitatum in a semi-deciduous forest, Itirapina area, São Paulo State, Brazil. Comparisons of bivouac and raiding pattern are done in relation to other subspecies of Eciton vagans.

Ecological aspects of the free-living ticks (Acari: Ixodidae) on animal trails within Atlantic rainforest in south-eastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Histopathology of tick-bite lesions in naturally infested capybaras (Hydrochoerus hydrochaeris) in Brazil

In the present work features of tick-bite lesions were evaluated in capybaras naturally infested with Amblyomma cajennense and Amblyomma dubitatum ticks. Gross appearance of tick bite site was characterized by a mild swelling and erythema. Microscopic examination revealed the cement cone, a tube-like homogenous eosinophilic mass penetrating deep into the dermis. This structure was surrounded in the dermis by a cellular infiltrate and free eosinophilic granules and was associated to edema of variable intensity. Necrosis was a common feature deep in the dermis particularly at the far end of the eosinophilic tube. Hyperplasia, cellular edema and occasionally necrosis of keratinocytes could be seen at both sides of the ruptured epidermis. Cellular infiltrate was constituted overwhelmingly by polymorphonuclear leukocytes with eosinophilic granules. In capybaras cells with such features can be either eosinophils or heterophils (pseudoeosinophils), the latter being the equivalent of neutrophils of other mammals. Ultrastructural analysis of the cellular infiltrate revealed the predominance of heterophils over eosinophils. Mononuclear cells and mast cells and, in lesser numbers, basophils were also seen at skin attachment sites. The presence of heterophils in the reaction of capybaras against Amblyomma ticks is an outstanding feature but its role in the reaction to the tick is not known. It is however speculated that capybara heterophils might be associated with a more permissive environment for tick feeding and pathogen transmission as already shown for the equivalent cell type, the neutrophil, in the reaction of the dog against the Rhipicephalus sanguineus tick.

Species diversity and seasonality of free-living ticks (Acari : Ixodidae) in the natural habitat of wild Marsh deer (Blastocerus dichotomus) in Southeastern Brazil

This study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the Parana river, in Brazil. Eight field trips (once per season) for collection of ticks were performed during 2 years. Using CO2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: Amblyomma cajennense, Amblyom\ma dubitatum, Amblyomma triste, Amblyomma coelebs, and Amblyomma nodosum. The seasonal pattern of A. cajennense was characterized by the highest peaks for adult ticks in the summer/spring months, for nymphs in the winter and for larvae in the autumn and winter. A. dubitatum and A. triste presented similar seasonal patterns characterized by peaks of adult ticks in the autumn. Nymphs of A. dubitatum peaked in the winter of the first year and in the winter/spring of the second year. A. triste was the only species to be collected in significantly higher numbers in the marsh than in surrounding drier areas such as forest patches. Among domestic animals living close the marsh areas, horses were infested by Anocentor nitens, A. cajennense, and Boophilus microplus, bovines were infested solely by B. microplus, and dogs were infested by Rhipicephalus sanguineus. Adults of A. triste showed to be well adapted to the marsh environment. This result, at least partially, explains local previous observations on the association of A. triste with marsh deer, as this vertebrate host inhabits mainly the marsh area. (c) 2006 Published by Elsevier B.V.

Ticks (Acari: Ixodidae) within various phytophysiognomies of a Cerrado reserve in UberlA cent ndia, Minas Gerais, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Carrapatos (Acari: Ixodidae) presentes em várias fitofisionomias de uma reserva no cerrado em Uberlândia, Minas Gerais, Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Amblyomma yucumense n. sp (Acari: Ixodidae), a parasite of wild mammals in Southern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)