Mamestra curialis (Smith, 1888)
BC : Northern Rockies Co.
AK Hwy @ One Thirteen Crk, 3297 ft
July 03, 2017, LG Crabo.
Specimen courtesy of LGCC
Photograph copyright: Merrill A. Peterson
Mamestra curialis is a moderately large noctuid moth (FW length 18 mm; n = 1) with a mottled nearly black forewing with ochre base and subterminal area and white reniform spot filling and subterminal line that flies in forests of British Columbia and the Rocky Mountains during summer. The forewing ground color is brownish black. The wing base is mottled with dark ochre scales to the antemedial line. Additional ochre scales are present in most of the subterminal area and in the apical terminal area, with the yellowish subterminal area as a major pattern element. The basal, antemedial, and postmedial lines are black, double filled with the ground color, fairly indistinct against the dark ground. The postmedial line is strongly toothed in the anterior wing and concave in the fold. The subterminal line is white, another prominent pattern element, sinuous with weak W-mark on the mid-wing, and preceded by the ground color. The terminal line is a series of black chevrons between veins. The fringe is of the ground color with thin black lines. The orbicular spot is black or absent and the claviform spot are black, filled with the ground. The reniform spot is outlined in black and filled with pure white traversed by netlike dark gray lines. The hindwing base is translucent pale gray with dark gray veins basally, dark gray distally, with a small pale mark along distal vein CuA2. The hindwing fringe is white with yellow and gray basal stripes. The head and thorax are dark gray. The male antenna is filiform, ciliate ventrally. The eye is covered by fine hairs.
This moth resembles several other moths in the tribe Hadenini, all of which have hairy eyes, as well as Mniotype in the Xylenini that lacks eye hairs. Mamestra curialis can be recognized by the combination of the subterminal area color, dark ochre medially and black distally, with white reniform and subterminal line. Mamestra curialis is most similar to Mamestra configurata and Spiramater lutra. Compared to M. curialis, M. configurata tends to be larger, has a reddish brown tint to the dark forewing areas, has light greenish rather than ochre color in the subterminal area that extends all the way to the subterminal line, a stronger W-mark of the subterminal line, and larger reniform spot with more white filling. Spiramater lutra lacks the extensive ochre in the subterminal area and has a rusty brown patch on the posterior wing base that M. curialis lacks.
Mamestra curialis occurs in boreal and montane forest.
Mamestra curialis has been found in northern, central, and eastern British Columbia as well as eastern Idaho in the Pacific Northwest. Most records are from the Rocky Mountains.
This boreal forest species is found across southern Canada to the Maritime Provinces. It also occurs in New England.
The larva of M. curialis is a cutworm that feeds on a variety of low plants.
This moth flies during the summer. All Pacific Northwest records are from July. It is nocturnal and comes to light.
This species is occasionally injurious to crops in eastern North America, particularly cabbage.
Forbes WTM. 1954. Lepidoptera of New York and neighboring states. Part III. Noctuidae. Cornell University Agricultural Experiment Station Memoir 329. 433pp.