Taxonomic keys, distributional data and hosts are provided for the 26 Amblyomma species known from Mexico. Members of this genus have been collected in 30 of Mexico’s 32 states and are associated with 43 nominal vertebrate taxa, of which 40 have been identified to species and four (Python sp., Myrmecophaga tridactyla, Tamandua tetradactyla, Tupinambis teguixin) are non-native. Mammals are the principal class of vertebrates parasitized by Mexican Amblyomma species, followed by reptiles, birds and amphibians. Our knowledge of Mexican Amblyomma is still far from complete because many potential hosts have not yet been examined and vast areas of the country remain unexplored.

Distribution and host data from published literature and previously unpublished collection records are provided for all nine species of the Holarctic tick genus Dermacentor that are known to occur in Mexico, as well as two species that may occur there. Parasite-host and host-parasite lists are presented, together with a gazetteer of collection localities and their geographical coordinates.

Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.

Resumen. Los ácaros constituyen el grupo más diverso de arácnidos con distribución cosmopolita, habitan ambientes terrestres y acuáticos, presentan una gran variedad de hábitos alimentarios y establecen diferentes relaciones con prácticamente todos los seres vivos. La riqueza de ácaros registrada hasta el presente en México es de 2 625 especies de 5 órdenes, lo que representa el 4.8% de la riqueza mundial (54 617 especies). El taxón mejor conocido es el de las garrapatas. Se discute el fenómeno de coextinción de especies.

Isolated populations of four species of Mexican parrots were sampled for evidence of selected pathogens of concern in birds originating in Latin America. Data were collected between June and September 1997, and ectoparasite collection was repeated with Rhynchopsitta pachyrhyncha in September 2000. Serum samples from nine Amazona oratrix, 10 Amazona viridigenalis, 6 Amazona autumnalis, and 25 R. pachyrhyncha chicks were screened for neutralizing antibodies to psittacid herpesvirus and avian influenza and for antibodies to paramyxovirus serotypes 1 and 3. Chicks were also examined visually for fecal parasites and ectoparasites. All serologic and fecal parasite tests were negative. Ectoparasites included ticks, Ixodidae; mites, Ornithonyssus sylviarum; fleas, Psyttopsylla mexicana; lice, Paragoniocotes mexicanus, Heteromenopon sp., and Psittacobrosus sp.; and bugs, Ornithocoris sp. This study provides baseline information to guide future health studies.