Smicridea (Rhyacophylax) villarricensis Flint 1983

Smicridea (Rhyacophylax) villarricensis

This species is clearly a member of the S. signata group and is the first member of the group known from south of the Amazon. The species is closest to S. lobata Ulmer but differs in possessing a broadly rounded apex to the tenth tergite and a shorter, broader ventral lip on the aedeagus.

ADULT.—Length of forewing, 4.5 mm. Width of eyes of male middorsally that of interocular distance. Color yellowish brown; forewing with a distinct, transverse pale band subapically, bordered outwardly by a narrow, darker band. Fifth sternum with anterolateral process slightly longer than sternum; without internal sacs.

Male Genitalia: Ninth segment with anterolateral process narrow; posterior margin middorsally produced into a narrow keel, with lateral surface concave below this keel. Tenth tergum with tip narrowly divided dorsally, tergites broadly rounded apically in dorsal aspect (often with these lobes partially overlapping); ventrolateral margin strongly sclerotized and produced into a rounded lobe ventromesally, the inner margin of which bears small denticles. Clasper with basal segment long, slightly expanded apicad; apical segment tapering to apex. Aedeagus with basal portion enlarged, apical portion at right angles to base; apex with dorsolateral margin slightly darkened, with a ventromesal process strongly expanded apically, internal sclerite long and slender, with a pair of small dark spots near midlength.

MATERIAL.—Holotype (male): PARAGUAY, DPTO. GUAIRÁ, 3.9 km S Villarrica, 2 Dec 1973, O.S. Flint, Jr., USNM Type 100533.

Paratypes: Same data as holotype, 1, 13.