Pacific Northwest Moths

Identification

Adults

Anarta antica is a small to medium-sized (FW length 14 - 16 mm) slightly yellow-tinted powdery light gray moth with a forewing pattern of thin black lines and spots and a white and gray hindwing that flies in dry forest and steppe habitats during the spring and  summer. The forewing is covered with a light even sprinkling of dark scales and is slightly darker gray toward the outer margin. The basal and antemedial lines are thin dark gray to black, double filled with the ground color. The basal line has a short black segment across the cell and is gray elsewhere. The antemedial line has two dark spots on the costa and is weaker elsewhere, irregular and slightly slanted toward the outer margin from the costa. The median line is gray, variable in prominence from a spot on the costa to complete across the wing. The postmedial line is thin black, evenly toothed, smoothly excurved around the reniform spot and oblique toward the base from the lower end of the cell. The subterminal line is pale, vague and irregular, mostly evident as a transition from darker gray in the subterminal area to the lighter terminal area. It is preceded by ill-defined light gray spots at the costa, on the mid-wing, and at the trailing margin. The terminal line is a series of spots. The fringe is concolorous with the terminal area. The outlines of the orbicular and reniform spots is thin black, incomplete at the anterior and posterior margins of both spots. The orbicular spot is oval filled with the ground color. The reniform spot is kidney-shaped, filled with the ground color anteriorly and gray posteriorly. The gray in the lower spot appears to be a component of the median line is specimens in which the line is dark. The claviform spot is small and black, often absent. The hindwing is pure white with a slight pearly sheen and is marked with an incomplete brown-gray marginal band that is darker and wider in females and dark gray veins that are darkest at the expected position of the postmedial line. The hindwing fringe is white. The head and thorax are uniform of the forewing color. The basal segment of the foretarsus has normal short spine-like setae. The eye is covered with fine hairs. The male antenna is filiform.

This species and Anarta decepta are closely similar in superficial appearance and can be distinguished from other Anarta species by the whitish gray forewing color with faint pattern of black lines and spots. They are best separated from each other by examining the first tarsal segment of the foreleg under magnification. Large curved tusk-like setae are present in A. decepta, but only normal short "spines" are present in A. antica. The forewings of these species are similar to those of Scotogramma submarina, a species that is restricted to southeastern Oregon in the Northwest. The hindwing of the Anarta species is much lighter than that of S. submarina.

Habitat

This species is found in desert habitats at low elevations in the Great Basin region.  It is moderately common on very dry sagebrush steppe in the Alvord Desert of southeastern Oregon. It has also been found in low elevation forest in the Siskiyou Mountains of southeastern Oregon.

Distribution

Pacific Northwest

Anarta antica is found in southern Oregon in the Northwest, from the Siskiyou Mountains to the deserts near Steens Mountain in Harney County.

Global

The range of this species is poorly defined due to confusion with Anarta decepta. It occurs in central and southern California and in Nevada. The range appears to extend to the western Great Plains where it is found from southern Alberta to west Texas.

Life History

Larvae

No information is presently available regarding larval foodplants of this species, but it probably feeds on herbaceous vegetation like related species.

Adults

Adults have a long flight season and are not only "early" as the species epithet antica suggests. Confirmed specimens of this species were collected from June through August.

Economic Importance

None.

Literature

Moth Photographers Group