Pacific Northwest Moths

Identification

Adults

Manduca sexta is a very large moth (FW length 52–59 mm). The forewing is mottled gray-brown and gray with a complex pattern of wavy black lines, including a complete black subterminal line. The forewing is very long, apically pointed, and concave posteriorly. It is mostly mottled gray-brown, grayer in the terminal area. The antemedial, postmedial, and subterminal lines are black and irregular, but usually discernible. The fringe is checkered black and white. The discal spot is small, black with a white center. The smaller hindwings are light whitish gray, slightly bluish in some specimens, with several black and dark gray to brown-gray bands. The outer margin is powdery gray and the fringe is white with gray checkering. The head and abdomen are dark gray-brown. The antennae are whitish, club-like. The robust abdomen has a black base and bright yellow and black bands on each dorsolateral segment which are separated in the midline by a hoary gray to gray-brown stripe. 

This rarely encountered species can be identified as belonging to the genus Manduca by the yellow and black spots on each side of the dorsal abdomen. It is similar to the much more common Manduca quinquemaculata. They can be differentiated by the shape of the forewing subterminal line, wavy and similar the other forewing lines in M. sexta and black, nearly straight, and more distinct than the other lines in M. quinquemaculata.

Habitat

This species appears to be a long-distance migratory stray, and is not an established resident in the Pacific Northwest.

Distribution

Pacific Northwest

The few Pacific Northwest records for this species are from southeastern Washington and Oregon's Willamette Valley.

Global

Manduca sexta has a large distribution throughout the New World, occurring as far south as Chile. In the United States it occurs from coast to coast. It is found as far north as Nebraska in the Great Plains and Massachusetts on the East Coast. Its western distribution is more limited to near the Mexico border, extending to California north of San Francisco along the Pacific Coast.

Life History

Larvae

This species is a foodplant specialist that feeds on various members of the Solanaceae such as tobacco, tomatoes, and potatoes in urban and agricultural habitats.

Adults

The few Pacific Northwest records are from May and September.  It typically occurs in late summer and early fall in most of its range.

Economic Importance

This species may cause economic damage to agricultural crops in the southern United States, but is of no significance in the Pacific Northwest.

Literature

BugGuide

Covell (1984)

Moth Photographers Group

Powell & Opler (2009)

Smith (1995)

Tuttle (2007)