Nasal mites of Tyrannidae ( Aves ) in Brazil

A total of 81 Tyraniidae birds were examined, 80 Pitangus sulphuratus (Linnaeus, 1766) (Great kiscadee), and one Machetornis rixosa (Vieilot, 1819) (Cattle tyrant), for collection of nasal mites, which were identified as Ptilonyssus spinosus (Brooks & Strandtmann, 1960) and Sternostoma longisetosae (Hyland, 1961) (Rhinonyssidae). This finding characterises the first report of P. spinosus and S. longisetosae in P. sulphuratus, and the first record of P. spinosus in M. rixosa, and expands the geographic distribution of these species. It is the first occurrence of S. longisetosae in the Neotropics, and the first citation of P. spinosus in the state of Rio Grande do Sul, Brazil.


Introduction
Pitangus sulphuratus (Linnaeus, 1766) (Great kiscadee) is endemic in the American continent.It is distributed from the United States (Texas) to Argentina, occurring throughout the Brazilian territory (Sick, 1997).Machetornis rixosa (Vieilot, 1819) (Cattle tyrant) occurs in Venezuela, Bolívia, Paraguay, Argentina, Uruguay, and in Brazil from the state of Maranhão to the state of Rio Grande do Sul (Mendes et al., 2000).

Material and Methods
Tyrannidae birds, a total of 81, being 80 Pitangus sulphuratus and one Machetornis rixosa, from these 59 P. sulphuratus were sent by the Núcleo de Reabilitação da Fauna Silvestres e Centro de Triagem de Animais Silvestres da Universidade Federal de Pelotas (NURFS-CETAS/ UFPEL), where the birds died; the others were found dead from having been run over.The birds were from the municipality of Pelotas and neighbouring municipalities which are located between the geographic coordinates a 31°00'58.44"S,52°03'13.34"Wand 33°32'06.45"S,53°21'08.98"W.
The collection of nasal mites was performed by adaptation of the technique of Fain (1957), cited by Amaral and Rebouças (1974), the specimens were cleared with lactophenol, mounted between slide and coverslip in Hoyer's medium and examined under an optical microscope.Identification was performed according to Systematic Keys of Pence (1975) and Knee and Proctor (2010), and the original species descriptions made by Brooks and Strandtmann (1960) and Hyland (1961).Parameters of prevalence, mean abundance and mean intensity were estimated according to Bush et al. (1997), as well as the sex ratio between males and females.

Results
The nasal mites were listed in the arthropod collection of the Laboratory of Wild Animals Parasitology, Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, with the numbering from 417 to 443.
Machetornis rixosa showed parasitism by two female of P. spinosus.

Discussion
This mite Ptilonyssus spinosus has been reported parasitising Tyrannidae birds in Cuba and in North America (Černý and Dusbábek, 1970, Pence 1975), and in Brazil, Amaral (1963) reported this species parasitising Tyrannus melancholicus melancholicus (Vieillot, 1819) in the state of Paraná.Knee and Proctor (2010) listed the occurrence of S. longisetosae in North American (Canada) tyrannids.
In the one bird, P. sulphuratus, there was a parasitic association between the two species, S. longisetosae and P. spinosus.Parasitic association between nasal mites is rarely cited.Pence (1973) reported the finding of multiple species in one host, but he neither indicated which species of mites were involved nor the hosts.Spicer (1987), in Mexico, has examined 103 birds from several families: four specimens belonged to Tyrannidae, and only one individual of the genus Empidonax (Cabanis, 1855) showed parasitic association between the mites Ptilonyssus tyrannus (Brooks and Strandtmann, 1960) and Sternostoma pencei (Spicer, 1984), concluding that parasitic association occurs sporadically.
Pitangus sulphuratus is a new host for the mites P. spinosus and S. longisetosae, as well as M. rixosa appear as a new host for the nasal mite P. spinosus.This report extends the geographic distribution of these species, being the first occurrence of S. longestosae in the Neotropics, and the first citation of P. spinosus in the state of Rio Grande do Sul.This is also the first report of parasitic association between P. spinosus and S. longisetosae.
Aknowledgements -We thank the Núcleo de Reabilitação da Fauna Silvestres e Centro de Triagem de Animais Silvestres da Universidade Federal de Pelotas for donating the animals, and CAPES and CNPq for financial support.