New records of chewing lice ( Insecta , Phthiraptera ) from birds of southern Brazil , with description of a new species

A collection of chewing lice was studied from the Natural History Museum of the Universidade Católica de Pelotas, Rio Grande do Sul, Brazil. Twenty three samples from 16 bird species were examined. Included therein was a new species of the genus Plegadiphilus Bedford, 1939 which is described, illustrated and compared to P. cayennensis Emerson & Price, 1969. An updated list of chewing lice species recorded from birds of that state is presented.

The Brazilian State of Rio Grande do Sul has 610 bird species from 21 orders reported to date (BELTON, 1994), which represents approximately 35% of the Brazilian avifauna.Despite such richness and diversity, the avian ectoparasites of the state are not well known.A few studies focusing on chewing lice (Insecta, Phthiraptera) have been conducted in this region, mostly on captive birds in rehabilitation centers.The relative ease of obtaining birds from such centers has stimulated additional studies in other parts of Brazil (FREITAS et al., 2002;SILVA et al., 2004SILVA et al., , 2009;;VALIM et al., 2005).
The first two native species of bird lice in Rio Grande do Sul were recorded in taxonomic papers made by GUIMARÃES (1943GUIMARÃES ( , 1947)), after which one species was included by PRICE & BEER (1968).However, the first published list of avian ectoparasites from the state, including chewing lice (FREIRE, 1958), reported only species from three domestic hosts, all of which are exotic to the Brazilian fauna.The most recent list of bird ectoparasites for Rio Grande do Sul (OLIVEIRA & GONZALES, 1990) includes, in addition to the three host species presented by FREIRE (1958), seven hosts, five of which are indigenous to Brazil.Although 13 species of chewing lice have been reported on birds from Rio Grande do Sul (FREIRE, 1958;AZEVEDO, 1973;OLIVEIRA & GONZALES, 1990), none of these were recorded on birds of the local fauna.
More recently, a few species of chewing lice were reported in the state on birds of the orders Anseriformes (BRUM et al., 2005), Ciconiiformes (BRUM et al., 2003;COIMBRA et al., 2005;ALBANO et al., 2005), Falconiformes (VALENTE et al., 2001;BRUM & RICKES, 2003), Gruiformes (BRUM et al., 2003); Rheiformes (SINKOC et al., 2005), Sphenisciformes (BRUM & BECKER, 2002).From these accounts, 13 species of chewing lice are currently known from native birds and 15 from birds introduced in Rio Grande do Sul.Additional studies of the chewing lice of birds from the state, their host relationships and geographical distribution are still unavailable.
Although chewing lice are permanent and obligate ectoparasites with a high degree of host specificity (JOHNSON & CLAYTON, 2003), some are less host specific (CLAY, 1964;WECKSTEIN, 2004).Thus there is great value in knowing the geographic distribution of the lice.Faunistic surveys, given the poor level of knowledge of such ectoparasites in Brazil, increase the chance of discovering new species, even on hosts from which many chewing lice have been described (e.g.Phimosus infuscatus (Lichtenstein, 1823)).
The present paper, in addition to contributing the description of a new louse species, also doubles the species known from Rio Grande do Sul and lists twelve new records for Brazil.

MATERIAL AND METHODS
Chewing lice were collected during the preparing of study skins at the Museu de História Natural da Universidade Católica de Pelotas (MUCPel) in Rio Grande do Sul, Brazil.In the present study only the birds processed from 2000 to 2006 and parasitized by chewing lice are considered.
The lice were initially preserved in 70% ethanol and some were mounted in permanent microscope slide preparations following the technique described by PALMA (1978).Most of the specimens examined were deposited in the entomological collection of the MUCPel.Type series are deposited in the entomological collection of the Instituto Oswaldo Cruz (CEIOC), Fiocruz, Rio de Janeiro, Brazil.
The scientific nomenclature and English names of birds follow the world list of DICKINSON (2003), the Portuguese names follow BELTON (1994), and nomenclature of chewing lice is that of PRICE et al. (2003).
Abbreviations of measured characters in the new species description are: HL, head length; FW, front width; TW, temporal width; CI, cephalic index (TW/HL); POW, prothorax width; PEW, pterothorax width; AW, abdomen width (at segment V level); PL, paramer length; GW, genitalia width (at basal plate level); TL, total length.Measurements are in millimeters and shown with their ranges.

RESULTS AND DISCUSSION
Twenty three samples of chewing lice from 16 host species representing 11 families and nine orders of birds are reported.All hosts belong to the native fauna of Rio Grande do Sul (BELTON, 1994), from six towns in the state.Only four towns were previously reported regarding chewing lice and their hosts: Passo Fundo (SINKOC et al., 2005), Pelotas (VALENTE et al., 2001;SINKOC et al., 2005), Rio Grande (BRUM & BECKER, 2002;SINKOC et al., 2005), and Sapucaia do Sul (BRUM & RICKES, 2003).Additional reports for the state lack information on geographical data of the hosts (BRUM et al., 2003(BRUM et al., , 2005;;COIMBRA et al., 2005;ALBANO et al., 2005).Thus, we report for the first time chewing lice species in the towns of Arroio Grande, Cidreira, Piratini and Santa Vitória do Palmar in Rio Grande do Sul, southern Brazil.
A total of 718 chewing lice specimens were collected, representing 26 species, one of them new to science, from three families: Menoponidae (11), Ricinidae (2) and Philopteridae (13) (Tab.I).Three samples could not be specifically identified due to the absence of adult specimens or morphological disagreement between the individuals collected and published descriptions.
The following bird species are reported for the first time as hosts of chewing lice: Anas platalea Vieillot, 1816, Turdus albicollis Vieillot, 1818 and Xolmis irupero (Vieillot, 1823).Remarks.Asio flammeus is the type host for C. brachysomum (PRICE & BEER, 1963a;PRICE et al., 2003).This is the first record of this host-parasite association for Brazil.Remarks.Phimosus infuscatus is the type and only known host for C. infuscati (PRICE et al., 2003), and was recorded from Ceará, northeastern Brazil by PRICE & EMERSON (1967).Recently, this chewing lice was reported in Rio Grande do Sul by COIMBRA et al. (2005), however this record is questionable because the host, Plegadis chihi (Vieillot, 1817), is normally infested with two different species of Colpocephalum Nitzsch, 1818.Remarks.Athene cunicularia is the type host for C. pectinatum (PRICE & BEER, 1963a;PRICE et al., 2003).This host-parasite association was recently reported for Brazil (SILVA et al., 2009).Remarks.Holomenopon brevithoracium is commonly found on anatids from around the world (PRICE, 1971;PRICE et al., 2003).In Brazil it has been reported only on Cygnus melanocoryphus (Molina, 1782) (BRUM et al., 2005;VALIM et al., 2005).Holomenopon boehmi Eichler, 1954 was described from a single male of Coscoroba coscoroba from a zoo and the authenticity of that finding has been questioned by PRICE (1971), although it is still considered a valid species (PRICE et al., 2003).The only specimen we found does not fit the morphological description of EICHLER (1954), resembling instead H. brevithoracium (PRICE, 1971).Thus, this species is recorded for the first time on C. coscoroba.
Remarks.Menacanthus eurysternus is found on 20 families, 70 genera and 176 species (PRICE et al., 2003), mostly from Passeriformes and a few Piciformes (PRICE, 1975).This is the first record of this host-parasite association, although this species has been reported recently in Brazil on Turdus leucomelas Vieillot, 1818 (ENOUT et al., 2009).

Menacanthus tyranni Price, 1977
Material examined.BRAZIL, Rio Grande do Sul: Pelotas Remarks.This species is known from three species of the genus Tyrannus Lacépède, 1799 (PRICE, 1977).It was recorded on P. sulphuratus by CASTRO & CICCHINO (1992) in Argentina.This is the first record of this hostparasite association for Brazil.
Lateral margin notched, with a deep, narrow slit.Head chetotaxy as in figure 6.
Etymology.The specific epithet refers to the Brazilian state in which the new species was discovered.
following characters: number of setae on tergites and sternites, with negligible variations; postspiracular setae long on tergites II-VIII; posterior projections on segments II-VI; female with one long seta on pleurites III-VI.But it may be promptly separable from latter species by the following characters: smaller in size in both sexes (total length 2.35 mm in female and 1.93 mm in males of P. cayennensis); in males, the parameres in genitalia are slightly straighter, bent only on their tips (curved on half of its length in P. cayennensis), all measurements taken were smaller for females of P. riograndensis Valim sp.nov.and the front margin of the head is more rounded (triangular shaped in P. cayennensis), metanotum with 16 marginal setae and only 8 of these long (instead of 12 long and total of 22 in P. cayennensis), vulvar margin slightly with more setae (only 20 in P. cayennensis).
Remarks.Guira guira is the type host for V. bergi (PRICE et al., 2003).This is the first record of this hostparasite association for Brazil.
Representatives of the family Menoponidae are specialized in living on the skin of their bird hosts, where they feed on skin desquamation, dermic secretions or blood (JOHNSON & CLAYTON, 2003).Four species of this family are herein reported for the first time in Brazil (Colpocephalum brachysomum, Menacanthus tyranni, Osborniella guiraensis, Plegadiphilus riograndensis sp.nov.), two additional species (Myrsidea elegans and Kurodaia fulvofasciata) are reported for the first time in Rio Grande do Sul.
Species of the family Ricinidae, like those of Menoponidae, live exclusively on the skin, however all members of the Ricinidae are obligate hematophagous (NELSON, 1972).The two species of ricinids identified in the present study are reported for the first time in Brazil, on new host species.Both R. arcuatus and R. marginatus are commonly found on various hosts of the family Tyrannidae (NELSON, 1972;PRICE et al., 2003).The finding of R. arcuatus on X. irupero and R. marginatus on P. sulphuratus hereby appears for the first time.The hosts examined were free-living; the samples included many lice of both sexes and were made in totally separate and spaced dates, what eliminates the chances of contamination within the same sampling.Thus these new host-associations are considered valid.
The present paper doubles the number of bird lice known from Rio Grande do Sul; in addition, an updated list of chewing lice previously found on birds in this state is given.Therefore, further studies on the lice associated with birds from other localities in Rio Grande do Sul and in other Brazilian states are be highly encouraged.

Table I .
Chewing lice (Insecta, Phthiraptera) currently known from birds in Rio Grande do Sul, Brazil ( †, introduced species to Brazilian bird fauna; *, questionable records).