Cucullia dorsalis Smith

Cucullia dorsalis Smith, 1892, Proc. U. S. Natl. Mus., 15:47.

Diagnosis: Cucullia dorsalis has been considered a race or subspecies of speyeri. However there are small, but consistent, differences in both superficial appearance and the male genitalia. The ranges of the two species appear to overlap marginally on the eastern edge of the Rocky Mountains, although the locality of the overlaping specimens, "Denver", is too vague to guarantee sympatry. A second area of possible sympatry is in southern Washington. Cucullia dorsalis is darker and the markings are more strongly etched with black than in speyeri, and the forewing anal dash is stronger and more likely to reach the postmedial line. The right clasper of the male genitalia is much smaller than it is in speyeri. The right and left valves are fairly symmetric in appearance, although the right clasper is still slightly larger than the left.

The ranges of dorsalis and laetifica overlap in southwestern Colorado. The two species in this region can be very difficult to separate superficially. In general dorsalis is larger and a more uniform gray color than laetifica. Cucullia laetifica often has a slightly bluish cast about it. Also the median area of the forewing in laetifica often has lighter area preceeding the postmedial line where it intercepts the anal dash. The claspers of the right and left valves of the male genitalia are almost equal in size in dorsalis, but the right clasper is markedly larger than the left in laetifica (compare the photos of the male genitalia). Wing length from base to apex: mean = 22.55 mm., standard deviation = 1.48 mm., n = 10.

Distribution: Cucullia dorsalis is a species of the western Rocky mountains and the Great Basin area. It has so far been found in most of Colorado except the far eastern part of the state, north to southern Washington, western Wyoming, northern New Mexico and Nevada, northern Arizona, Utah, and central California. There does not appear to be any significant variation either geographical or individual in dorsalis other than the sexual dimorphism in hindwing wing coloration typical of the group.

Adults have been collected from May to August.

Identification Quality: Excellent

Larva: Unknown

Foodplants: The larva of this species has not been described. There are two adult specimens from California in the USNM reared from Machaerantha shastensis, an herbaceous composite, but no associated larvae. There is also a single female from Weld County, Colorado reared from Helianthus sp. (Asteraceae). Crumb's (1956) "Cucullia #8" may be this species. It belongs to the group and is most similar to speyeri but has an isolated anterior dorsal yellow marking as in laetifica.

Similar Species

Cucullia speyeri

Cucullia laetifica