A review of Parydra ( Diptera : Ephydridae ) from Brazil

Species of the shore-fly Parydra Stenhammar, 1844 from Brazil are reviewed with an emphasis on the fauna from southern Brazil, where one new species, Parydra arcuata sp. nov. - state of Parana, municipality of Castro (8 km N, 24o45.3'S, 49o58.9'W) -, has been discovered and is herein described. To facilitate identification of species, we have included a diagnosis of the genus. We have also provided illustrations of structures of the male terminalia for all included species.

Both larvae and adults of Parydra feed on algae and are found along the muddy shores of lentic and lotic aquatic systems (BISCHOF & DEONIER 1985, FOOTE 1995).

MATERIAL AND METHODS
The descriptive terminology, with the exceptions noted in MATHIS (1986) and MATHIS & ZATWARNICKI (1990a), follows that published in the 'Manual of Nearctic Diptera' (MCALPINE 1981).Because specimens of Parydrini are generally moderately small, usually less than 4.0 mm in length, study and illustration of the male terminalia required use of a compound microscope.We have followed the terminology for most structures of the male terminalia that other workers in Ephydridae have used (see references in MATHIS 1986, MATHIS & ZATWARNICKI 1990a, b), such as surstylus.ZATWARNICKI (1996) suggested that the preand postsurstylus correspond with the pre-and postgonostylus and that the subepandrial plate is the same as the medandrium.The terminology for structures of the male terminalia is provided in the legends.
Dissections of male and female genitalia and descriptions were performed using the method of CLAUSEN & COOK (1971) and GRIMALDI (1987).Microforceps were used to remove abdomens, which were macerated in a potassium hydroxide solution.Cleared genitalia were rinsed in a dilute solution of acetic ZOOLOGIA 28 (4): 505-512, August, 2011 acid and then transferred to glycerin for observation and illustration.If necessary for proper orientation, the specimen was transferred from glycerin to glycerin jelly.The glycerin jelly was heated, and the specimen appropriately oriented.After cooling, the embedded specimen in glycerin jelly became immobilized.The abdomen was placed in a plastic microvial filled with glycerin and attached to the pin supporting the remainder of the insect from which it was removed.
The new species description is composite and not based solely on the holotype.Two head and two venational ratios used in the descriptions are based on three specimens (largest, smallest, and one other): eye ratio: maximum width/maximum height; gena-to-eye ratio: genal height (immediately below maximum eye height)/eye height; costal vein ratio: the straight line distance between the apices of R 2+3 and R 4+5 /distance between the apices of R 1 and R 2+3 ; M vein ratio: the straight line distance along vein M between crossveins dm-cu and r-m/distance apicad of dm-cu.
Specimens for this study are in the American  Zatwarnicki, 1995: 216-229 [world catalog].
Diagnosis.Parydra is distinguished from other genera of Parydrini by the following combination of characters: Small to large shore flies, body length 1.85-5.50mm; usually densely golden, coppery, and grayish microtomentose.Head: frontoorbital and ocular setae present, lateroclinate, frequently not well developed.Arista well developed, macropubescent.Face in lateral view straight to concave or convex, usually densely microtomentose, coppery, golden to silvery white; anterior oral margin in lateral view extended beyond antennal bases; facial carina near antennal bases, not extended beyond level of oral margin; facial series of setae with only dorsal seta or 2 developed, inserted near parafacial; oral margin lacking setae.Clypeus exposed and generally visible.Thorax: wing with costa long, extended to vein M, making costal section II over 3X length of section III; crossvein r-m located distinctly beyond level of junction of vein R 1 with costa.Abdomen: heavily sclerotized; black with gray to coppery microtomentum.Male terminalia: Epandrium usually greatly narrowed dorsally above cerci; surstylus fused with ventral margin of epandrium; aedeagus and phallapodeme sometimes fused; gonite variously shaped but usually elongate and often narrowly rounded or pointed apically.Female ventral receptacle variously shaped, operculum often large, thimble-like with small extended process but also with operculum small and with a relatively larger extended process.
Remarks.Although no specimens of this species are known from Brazil, we have included it in this review as it has been recorded from adjacent countries (MATHIS & ZATWARNICKI 1995) and may eventually be found in Brazil.
Type material.The holotype male is labeled "BRAZIL.Etymology.The species epithet, arcuata, is of Latin derivation, meaning "bent like a bow," and has reference to the arched hindfemur of males.Diagnosis.This species is distinguished from congeners by the following combination of characters: Medium-sized to large shore flies, body length 3.20-3.95mm.Head: fronto-orbital setae relatively long; face in lateral view convex; clypeus golden to grayish gold; maxillary palpus usually yellowish.Thorax: scutellum lacking apical process or papilla; apical setae lacking basal tubercles.Wing relatively clear, lacking conspicuous spots or darkened areas; wing ratio: 0.40-0.46;costal vein ratio: 0.60-0.70.Legs, except black base of coxae, reddish to yellowish red, apical tarsomeres brown; hindtibia with yellow posteroapical comb, paler than rest of tibia; gonites flattened, with rounded, slightly curved apices.

ACKNOWLEDGMENTS
We gratefully acknowledge the assistance and cooperation of many organizations and individuals who contributed to the field work and production of this paper.The illustrations were expertly produced by Mirian N. Morales, who is gratefully acknowledged and thanked.The plates were assembled by Michael Biondi and Karolyn Darrow.The latter also expertly photographed and assembled the plate of heads and the hindleg of P. arcuata sp.nov.