Ochrotrichia tarsalis (Hagen 1861)

Ochrotrichia (O.) tarsalis (Hagen)

Hydroptila tarsalis Hagen, 1861:275.

Polytrichia tarsalis (Hagen).—Ross 1938a: 10.—Fischer 1961:176.

Ochrotrichia tarsalis (Hagen).—Ross 1944:130—Edwards and Arnold 1961:412.—Blickle 1962:154.—Fischer 1971: 298.

This species is very widely distributed in North America, being known from Florida, Illinois, Indiana, Missouri, New York, Oklahoma, Ontario, Texas, Virginia, and Wisconsin. This is the first record from Latin America.

The species is probably most closely related to O. stylata (Ross), from which it is easily distinguished by the hooked basal and the spiral apical processes of tenth tergum.

ADULT.—Length of forewing, 2 mm. Color in alcohol, pale brown. Male genitalia: Ninth tergum deeply depressed and produced anteriad. Tenth tergum with a short, heavy spine basally on left and a hooked spine just beyond; ventrally on left a short, laterally directed spine; beyond basal section a broad, flat, dorsal plate, which bears on right ventral surface a slender process with a twisted apical section ending in a dark point, apical twisted section covered by a flat lobate sclerite. Clasper long, slender, apex rounded; with a row of black peglike setae around apex and along ventral margin; midbasal ridge nearly vertical, that of right clasper bearing a blackened point ventrally; dorsal margin bearing a small mesal point, that of right clasper near midbasal ridge, that of left clasper apicad of ridge. Aedeagus slender, threadlike.

MATERIAL.—MEXICO: SAN LUIS POTOSI: El Salto, 3 June 1967, O. S. Flint, Jr., 1♂.