Nocloa rivulosa Smith

Nocloa rivulosa Smith, 1906, Jour. New York Ent. Soc., 14: 14.

Diagnosis: Nocloa rivulosa and pallens form a pair of sister species, although superficially they appear quite different. Nocloa rivulosa is brown and the forewing has a distinctive striate appearance caused by the doubling of all of the lines in the forewing. The antemedial line is vague, but highly dentate. The lower half of the basal area is slightly darker than the upper half. The orbicular spot is absent and the reniform spot is represented by a most a vague light line; the median line is dark and is sometimes the most distinctive feature of the forewing. In particular the upper part of the medial line forms a slanting mark between the positions of the orbicular spot and reniform spot. The subterminal line is strongest toward the costa and makes the apex of the forewing appear slightly dark than the rest of the wing.

In rivulosa and pallens the gaps between the lateral outlines of the frontal prominence are not as distinct as in plagiata and make the ring appear more confluent with the clypeal margin than in plagiata. The central prominence is also more produced and more ovate than in plagiata. In the male genitalia the clasper of the valve is not c-shaped as in plagiata and the valve itself is not as distinctly rectangular. In the vesica of the aedoeagus the smaller group of spines are much longer than those of plagiata. Wing length: mean = 11.45 mm, standard deviation = 0.44 mm, n = 10.

The adult is a spring flier and has been collected from February until early May.

Distribution: This species occurs primarily in the drier areas of southern California, but also occurs in southern Nevada and southern Arizona as far east as Phoenix. In Mexico it has been collected in Baja California del Norte and western Sonora. The hindwing of the female is darker than that of the male, but otherwise the sexes are not dimorphic. Individuals differ in the distinctness of the markings, particularly the strength of the medial line. A couple of specimens have a very strong contrast between the dark and lighter areas.

Identification Quality: Excellent

Larva: Unknown

Foodplants: Unknown

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