Pacific Northwest Moths

Identification

Adults

Eumorpha achemon is a very large moth (FW length 44–45 mm) with boldly geometrically-patterned tan and dark brown thorax, a similar forewing pattern, and bright pink hindwing.  The forewing is long and narrow with a slightly hooked tip.  It is medium-dark gray-tan, lighter gray on the basal and posterior forewing, and darker and browner toward the outer margin.  The median area posterior to CuA2, the apex, and anal angle are marked with sharply-defined patches of velvety warm brown.  A small black spot is located near the wing base.  The hindwings are bright pink, darkest near the anal angle.  The outer margin is powdery gray-tan, lighter gray posteriorly, with a brown and black submarginal band that is divided into discrete spots on the posterior half of the wing.  The head and thorax are similar to the forewing ground color, with dark triangular tegulae.  The antenna is whitish, club-shaped. The abdomen is gray-tan with weak banding on each segment.

This species can be definitively identified by its very large size, tan color with distinctive geometric dark brown patches on the forewing and each side of the thorax, and pink hindwing.  It is unlikely to be confused with any other species in our area.

Habitat

Eumorpha achemon is moderately common in riparian areas with grape (Vitis spp., Vitaceae).

Distribution

Pacific Northwest

Records of this species are most common in southwestern Oregon in our area, although isolated occurrences are documented through the Willamette Valley into south-central Washington.  It appears to be an established resident in the Klamath Mountain Ecoregion (Edna Bottorff personal communication 2011).  It has been collected in northwestern Wyoming near the eastern edge of the Pacific Northwest but has not been found in eastern Idaho or western Montana.

Global

Eumorpha achemon is widespread in North America north of northern Mexico.  It is found across the southern part of the United States, ranging as for north as southern New England in the east, southern Saskatchewan in the Great Plains, and northern Utah in the Rocky Mountain region.  It is absent from most of Nevada but occurs in most of California west of the Sierra Nevada crest.

Life History

Larvae

This species is a foodplant specialist feeding on various members of the Vitaceae including cultivated grapes (Vitis spp.).

Adults

Adults are crepuscular and nocturnal and visit flowers for nectar.  They are attracted to lights.  The few Pacific Northwest records are from June and again in August and September.

Economic Importance

This species may be a local pest on grape vines in urban areas.

Literature

BugGuide

Moth Photographers Group

Powell & Opler (2009)

Tuttle (2007)