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In 2000, we initiated an investigation on the tick fauna of Rondônia State, where we collected many specimens of Amblyomma scalpturatum Neumann, 1906 and Amblyomma incisum Neumann, 1906. In addition, we also collected a third group of ticks that were morphologically closely related to those 2 species, but sufficiently different to be considered a distinct species; members of this group were subsequently identified as Amblyomma latepunctatum Tonelli-Rondelli, 1939, through comparison with the type specimens of this taxon. Herein, we redescribe both sexes of A. scalpturatum and A. incisum, the female of A. latepunctatum, and provide the first description of the male of this latter species. Molecular analysis of the second internal transcribed spacer (ITS2) from rDNA of specimens of the 3 species supports morphological results. Examination of both A. scalpturatum and A. incisum deposited in different tick collections revealed that A. latepunctatum appeared relatively frequently in the vials believed to contain specimens of A. incisum or A. scalpturatum. Before this study, A. latepunctatum was considered a synonym of A. scalpturatum. Herein, we provide morphological and molecular evidence to validate the species A. latepunctatum. The South American tapir (Tapirus terrestris) seems to be the primary host for the adult stage of A. latepunctatum, A. scalpturatum, and A. incisum.

During a survey of ticks on horses in November 2000, at the University of São Paulo farm in Pirassununga county, São Paulo, Brazil, 1 gynandromorph of Amblyomma cajennense was collected from a naturally infested horse. In another survey on dogs in March 2001, in the urban area of Monte Negro, Rondônia, Brazil, a gynandromorph of Rhipicephalus sanguineus was collected from a naturally infested dog. Both specimens are described and classified as perfect bipartite protogynanders.

We examined files of various families for the presence of trypanosomatids. Of 592 insects, 113 (19%) were positive. From these insects, we obtained 42 cultures and selected 14 for further analysis. Seven of the cultures had the characteristics of Herpetomonas species, they displayed typical opisthomastigotes, lacked arginase, possessed a Pvu II restriction site at 360 bp from the 5' end of the small subunit ribosomal gene, and did not possess a Hin dIII site at 1,500 bp from the ribosomal alpha-large subunit 5' end. Hybridization with synthetic oligonucleotides complementary to the sequences flanking the Pvu II site in Herpetomonas samuelpessoai and Herpetomonas muscarum, permitted the distribution of the old species and the 7 isolates into 2 subgroups of Herpetomonas spp. Of the remaining 7 cultures, 4 were probably Leptomonas spp., whereas the other 3, together with Herpetomonas roitmani, seem to constitute a novel group with morphological and molecular characteristics quite distinct from those of Herpetomonas spp. or any other genera of Trypanosomatidae. We also studied some trypanosomatid species of questionable taxonomic status, Leptomonas samueli and Phytomonas davidi yielded results identical to those of Herpetomonas spp., thus confirming their already suspected affiliation to this genus. On the other hand, Herpetomonas anglusteri, Herpetomonas dedonderi, and Herpetomonas mcgheei displayed morphological and molecular characteristics incompatible with their placement in the genus Herpetomonas.

Fifty-four species or isolates of insect trypanosomatids were examined for the presence of selected restriction enzyme sites in the small (SSU) and large (LSU) rRNA coding units of ribosomal genes. In the SSU, sites for Eco RI, Bgl II, Pst I, and Hind III were found to occur at the same location for all species examined, thus displaying a universal distribution among trypanosomatids. In the LSU, a site for Bgl II in the 24S-alpha sequence and sites for Hind III and Pst I in the 24S-beta sequence were found in all species examined. In contrast, a site for Pvu II in the SSU exhibited a genus-related distribution, being present in Crithidia and Herpetomonas but absent in Phytomonas. A site for Hind III in the 24S-alpha sequence of the LSU also exhibited genus-restricted distribution. The site was present in Crithidia but absent in Phytomonas and Herpetomonas. These findings were confirmed by dot hybridization with a synthetic oligonucleotide complementary to the 18S rRNA sequence containing the Pvu II site. Results point to the usefulness of restriction markers as diagnostic tools for distinguishing the lower trypanosomatid genera Crithidia, Herpetomonas, and Phytomonas at the same time revealing a marked complexity within the genus Leptomonas.