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| Author(s): |
Thiago Fernandes Martins
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2009-12-17 |
| Examining board members: |
Marcelo Bahia Labruna;
Darci Moraes Barros Battesti;
Hilda Fátima de Jesus Pena
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| Advisor: | Marcelo Bahia Labruna |
| Abstract | |
Together with the larval stage, the nymphal stage of ticks of the genus Amblyomma are the most aggressive ticks for humans entering in areas inhabited by wild life and some domestic animals. However, due to the inexistence of morphological description of the nymphal stage of many Amblyomma species that occur in Brazil, together with the lack of a taxonomic key for these ticks, little or nothing is known about the biology and ecology of Amblyomma spp nymphs that parasitize humans and animals in the country. The great majority of the studies have concentrated in the tick adult stage, for which morphological descriptions and taxonomic keys are available for all known species. In the present study, the morphological description of the nymphal stage, illustrating important characters through scanning electron microscopy, was performed for nymphs of following 15 Amblyomma species that occur in Brazil, for which the nymphal stage had never been described: Amblyomma aureolatum (Pallas, 1772), Amblyomma auricularium (Conil, 1878), Amblyomma calcaratum Neumann, 1899, Amblyomma coelebs Neumann, 1899, Amblyomma fuscum Neumann, 1907, Amblyomma humerale Koch, 1844, Amblyomma incisum Neumann, 1906, Amblyomma latepunctatum Tonelli-Rondelli, 1939, Amblyomma naponense (Packard, 1869), Amblyomma nodosum Neumann, 1899, Amblyomma ovale Koch, 1844, Amblyomma pacae Aragão, 1911, Amblyomma pseudoconcolor Aragão, 1908, Amblyomma scalpturatum Neumann, 1906, Amblyomma varium Koch, 1844. In addition, the nymphal stage of the following 12 Amblyomma species, which had been previously described, were redescribed: Amblyomma brasiliense Aragão, 1908, Amblyomma cajennense (Fabricius, 1787), Amblyomma dissimile Koch, 1844, Amblyomma dubitatum Neumann, 1899, Amblyomma longirostre (Koch, 1844), Amblyomma oblongoguttatum Koch, 1844, Amblyomma parkeri Fonseca e Aragão, 1952, Amblyomma parvum Aragão, 1908, Amblyomma romitii Tonelli-Rondelli, 1939, Amblyomma rotundatum Koch, 1844, Amblyomma tigrinum Koch, 1844, Amblyomma triste Koch, 1844. The descriptions and redescriptions totalized 27 species. Only two species (Amblyomma geayi Neumann, 1899 and Amblyomma goeldii Neumann, 1899) out of the 29 Amblyomma species established in Brazil were not included in the present study. Nymphal specimens used for morphological descriptions or redescriptions were derived from laboratory colonies that were started with field-collected adult ticks, previously identified to species. The only exception was A. parkeri, which was redescribed from a single nymphal specimen that was available in a tick collection. For each tick species, scanning electron microscopy-photographs are presented for at least four anatomic regions: dorsal capitulum, ventral capitulum, dorsal scutum, and coxae I, II, III, IV. Finally, a dichotomic key was constructed to support taxonomic identification of the nymphal stage of 27 Amblyomma species established in Brazil. (AU) | |