A medium-size (2.8.3.0 cm wingspan) dull yellow brown moth, without darker markings. The forewing color is slightly darker on the lower half, inside the postmedian line near the apex and in an indistinct band running from the postmedian line through the reniform area. It is also lighter along the distal side of the postmedian line, in particular just below the apex. The reniform is marked by a few grey scales in some specimens, obsolete in others. The hindwing is dull white, lightly dusted with brown scales, especially near the outer margin. Antennae simple, sexes similar.  The related P. spumosum is larger more evenly colored and has more pointed forewings. A key to the species of Plagiomimicus, along with illustrations of both adults and the genitalia of both sexes, is provided in Poole, 1995. 

Mainly a prairie species, from remnant prairies in Illinois west to southern Saskatchewan and Alberta, Idaho, Utah and New Mexico. Known from Canada only in Saskatchewan (1 record) and Alberta. In Alberta it has been collected north to Lethbridge and Medicine Hat.

Dry open areas; disturbed areas in the dry grasslands region.

No Alberta data; elsewhere Iva xanthifolia (Asteraceae) has been recorded as a larval host (Crumb, 1956)

Adults have been collected in Alberta in late July and early August.

Poorly known. There is a single annual brood, with the adults flying in mid summer. The larvae have been described by Crumb (1956). The larvae undoubtedly feed on the seeds in the flowering heads, as do all known members of the family.   

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 2
Species With Barcodes: 1

At the northwestern edge of it's range in Alberta and Saskatchewan, where it is local and rare.