Comprehensive DescriptionRead full entry
General DescriptionA medium-size (3.5-5.0 cm wingspan) broad-winged moth. Color quite variable in both sexes. The FW of females is dark chocolate brown, almost black in the basal and costal one-third, paler and red-brown in the outer half. The ST line is black and well defined along the lower two-thirds, darker distally except for apex region. HW chocolate brown striated with many faint black bands, and with a nearly straight black line with paler yellow brown scaling along the outer edge crossing the outer third. Both wings moderately scalloped. Male smaller, brighter. Basal one quarter and costa dark brown, most of median area bright red-brown or mahogany, separated from the basal area by a lighter grey band. The terminal area is light yellow-brown or cream divided into an upper and lower patch. HW like female but lighter brown, and with a pale patch on the lower one-third. Antennae simple. Similar-wings greatly resemble geometrid moths, both in their unusually patterned HW and their habit of resting flat with wings partially opened. The Mahogany Similar-wing is very similar to the Lunate Similar-wing (Z. lunata)which, although not yet taken in Alberta, occurs both to the east and west and should be watched for. Questionable specimens should have their identity confirmed by examining the genitalia. Alberta specimens are referable to ssp. norda, a brighter form, named from southern Alberta material.