Orthodes obscura (Smith, [1888])

93-3142

Identification

Adults

Orthodes obscura is a dark black-brown to red-brown small to medium-sized moth (FW length 14 - 16 mm) with a black and pale subterminal line that is strongest on the posterior wing that flies in forests north of northern Oregon during the summer. The color is even, slightly lighter and more reddish in the posterior median area in a few specimens. The basal, antemedial, and postmedial lines are usually absent, occasionally visible as slightly pale lines. The postmedial line is a series of paired inner black and outer pale slightly yellowish spots that are strongest near the trailing margin. A few specimens have a terminal line of pale spots on the vines. The fringe is similar to the rest of the wing, very weakly checkered with lighter brown in a few specimens. The orbicular spot is black with filling of the ground, round or oval. The reniform spot is broad and kidney-shaped, black in outline with incomplete filling of similar light scales as the outer part of the subterminal line. There is no claviform spot. The hindwing is medium brown-gray with extensive dark gray suffusion, postmedial and submarginal lines, and a dark thin terminal line. The hindwing fringe is slightly paler gray, sometimes with a pink tint. The head and thorax are dark black-brown with lighter margin on the collar. The eye is hairy. The male antenna is bead-like.

This species resembles Melanchra pulverulenta and Melanchra assimilis in the tribe Hadenini. Both of these species have hairy eyes and a pale subterminal line on a dark ground; however, the subterminal line lacks the black inner component that is present in O. obscura

Habitat

This species is widely distributed across Canada in moist forest habitats, extending westward to the northern Rocky Mountain region.  In the Pacific Northwest, it is found in mixed hardwood-conifer forests at middle elevations.

Distribution

Pacific Northwest

Orthodes obscura is found in forests of south-central British Columbia and in the mountains of the eastern parts of the Northwest. The range extends west to northeastern Washington and the Blue Mountains in southeastern Washington and northeastern Oregon.

Global

This species is found in boreal and montane forests across North America. It is found as far east as southern Quebec. The range extends from central Alberta to Colorado in the Rocky Mountain region.

Life History

Larvae

No information is presently available regarding larval foodplants of this species.

Adults

Adults fly relatively early in the summer and are often worn when found. They have been collected from late May to early July in the Northwest. This species is nocturnal and comes to lights.

Economic Importance

None.

Literature

BugGuide

Forbes (1954)

Moth Photographers Group