Pacific Northwest Moths

Identification

Adults

Spaelotis velicava is a rare Spaelotis in the Pacific Northwest. It reaches the northern limit of its range in southern Idaho. It is a medium-sized moth (FW length 17 - 18 mm) with a streaky gray-brown forewing and dark gray hindwing. It is one of five of our Spaelotis species which have an almost identical superficial appearance. The forewing is elongate and fairly smooth gray-brown in color. A thin, black, basal dash is present. The lines are slightly darker than the ground color and filled with lighter brown or gray-brown. The antemedial line is jagged but faint, often visible only at the costa. The postmedial line is also uneven. It is drawn abruptly drawn toward the base at the costa, is laterally convex from the superior cell to the fold, and nearly straight to the trailing margin which it meets at a right angle. The subterminal line is absent or a series of pale spots. The orbicular spot is black, long and oval, and touches the reniform spot or is connected to it by a thin black line in the cell. It is filled with light gray-brown. The reniform spot is incomplete or absent, usually evident as a black line at the medial wall and a dot at the indentation of the lateral wall. It is filled with the ground color or slightly lighter gray-brown. The hindwing is medium brown-gray with slightly darker veins and discal spot. The head and thorax match the forewing ground color. The male antenna is filiform.

 Spaelotis velicava is most likely to be confused with Spaelotis havilae and Spaelotis bicava. This species is darker brown and smoother with markings nearly limited to the black spots and has a lighter gray hindwing. Three other streaky species in southern Oregon and Idaho are more closely similar to it in superficial appearance, although all three lack a form with an orange tint on the forewing costa. All Spaelotis females are best identified by the size, shape, and placement of a set of shallow pits on the posterior ventral abdomen which lose their covering of loose scales after mating. Those of S. bicava have two relatively large shallow triangular pits that are situated next to each other near the tip of the abdomen. Spaelotis males are best identified by association with the females, but can also be distinguished by dissection.

Habitat

This species is endemic to the Great Basin in desert and dry forest habitats.  It barely enters the Pacific Northwest in northern Nevada and southern Idaho.

Distribution

Pacific Northwest

Spaelotis velicava is found in southern Idaho in our region.

Global

This species' range lies slightly to the east of that of Spaelotis havilae, although the two overlap in eastern California near Mono Lake and in northern Nevada. Spaelotis velicava is also found throughout most of Utah into western and southern Colorado.

Life History

Larvae

No information is presently available regarding larval foodplants of this species, but it is probably a climbing cutworm that feeds on both hardwoods and herbaceous vegetation based on related species.

Adults

The few Pacific Northwest records of this species are from July and late August. It is nocturnal and comes readily to lights.

Economic Importance

None.

Literature

Lafontaine (1998)

Moth Photographers Group