Pacific Northwest Moths

Identification

Adults

Agrochola lota is a medium-size recently-introduced Eurasian noctuid moth (FW length 15 mm) with dark red and pale ochre subterminal line on a uniform yellowish, reddish, or purplish gray forewing that flies in southwestern British Columbia and adjacent Washington during late fall. The forewing color is even, variably tinted yellowish, reddish, purplish, or lead gray, darker along the costa and outer margin and lighter in the terminal area. The most common colors in the Pacific Northwest is slightly purplish gray or lead gray, but reddish or yellow forms are known. The basal, antemedial and postmedial lines are nearly obsolete, evident only on the costa or as thin black lines on the veins. The medial line variable, absent to sooty gray. In contrast, the subterminal line is prominent, nearly straight, with dark red inner and ochre outer components. The terminal line is a series of sooty dots between veins. The fringe is sooty gray with thin ochre base. The orbicular and reniform spots outlines are thin gray, black, or dark red. Both spots are filled with the ground color, except black in the lower reniform spot. The orbicular spot is round or slightly ovoid. The reniform is an upright oval with straight medial and lateral sides. The hindwing is lustrous orange tan with gray veins and discal spot, and extensive gray shading between veins and near the distal margin. The head and thorax are uniform dark gray. The male antenna is filiform, densely ciliate ventrally.

This moth is unlikely to be confused with other late-fall-flying noctuid moths. It differs from both other Agrochola species in area in being gray rather than orangish or reddish. Dark gray in the lower reniform spot and a straight red subterminal line are typical features of A. lota, but the ground color varies slightly between individuals. Agrochola lota is strikingly similar in color and pattern to Orthosia revicta, a spring flying moth. The eyes of A. lota lack hairs, a prominent feature of Orthosia and other species in the tribe Orthosiini. These species can also be distinguished by the date of observation, late fall for A. lota and spring for O. revicta.

Habitat

This species has been found in a number of lowland sites in the Lower Mainland of British Columbia, adjacent Gulf of Georgia islands, and adjacent Whatcom County, Washington. 

Distribution

Pacific Northwest

This species has been found in a number of lowland sites in the Lower Mainland of British Columbia, southern Vancouver island and adjacent islands, and Whatcom County, Washington. It was first detected in the Pacific Northwest near Vancouver in 2018. It appears to be spreading in southwestern British Columbia and adjacent Washington, having reached Bellingham, Washington in 2022.

Global

This species is introduced to North America from Eurasia, most likely Europe. It was established in the Northeast prior to being discovered in Vancouver, British Columbia, suggesting that the Pacific Northwest moths were introduced here from eastern North America through human transport as there is no evidence for contiguous spread across the continent (unlike for some other introduced species like Noctua pronuba). Agrochola lota is widespread in the Old World, occurring in most of Europe to the Altai Mountains.

Life History

Larvae

The larva feeds on a variety of hardwood trees and shrubs, preferring willow (Salix spp. (Salicaceae)) and alder (Alnus spp. (Betulaceae)).

Adults

Adults of A. lota are one of the latest-flying noctuids. Fresh specimens are routinely observed in October and November.

Economic Importance

None.

Literature

BugGuide

Moth Photographers Group

Ronkay L, Yela JL, Hreblay M (2001) Hadeninae II.—Noctuidae Europaeae, volume 5. Entomological Press. Sorø. 452 pp.