Ochrotrichia stylata (Ross 1938)

Ochrotrichia (O.) stylata (Ross)

Polytrichia stylata Ross, 1938b: 120.—Fischer 1961: 176.

Ochrotrichia stylata (Ross).—Ross 1944:131.—Denning 1947a:171; 1947b:146.—Fischer 1971:298.

O. stylata is widely distributed in the western United States: Arizona, California, Colorado, Montana, Oklahoma, Oregon, South Dakota, Utah and Wyoming. It also has a fairly wide distribution in Central America.

This species is closely related to O. tarsalis (Hagen) from which it is easily distinguished by the structure of the tenth tergum, especially by the presence of only a single basodorsal spine in O. stylata.

ADULT.—Length of forewing, 2.5 mm. Color in alcohol, pale brown. Male genitalia: Ninth tergum deeply depressed and produced anteriad. Tenth tergum with a single elongate, basodorsal spine to left of midline, and another short basoventral spine on left; a large, flat plate covering dorsum, beneath which lies a single spine barely protruding beyond plate, a longer spine beneath right side projecting considerably beyond plate and laying alongside a more membranous, slightly twisted process. Clasper long, narrow, apex rounded, with a row of black peglike setae around apex, along ventral margin and midbasal ridge. Aedeagus long and threadlike.

MATERIAL.—GUATEMALA: ESCUINTLA: Escuintla, Grutas de San Pedro Martir, 10 August 1965, P. J. Spangler, 1♂. MEXICO: SAN LUIS POTOSI: El Salto, 3 June 1967, O. S. Flint, Jr., 1♂; VERACRUZ: Fortin de las Flores, 17 May 1964, Blanton et al., 17♂; same, but 22 May 1965, Rabago, 1♂.