Montana Field Guide

The Rosey Dart (Diarsia rosaria) forewing is red-brown often with the discal cell black between the discal spots. The wingspan is 33 mm (Powell and Opler 2009).

Shropshire and Tallamy (2025) provide a list, with synonymies, of 13,055 described native, exotic, and occasional straying Lepidoptera species of North America, north of Mexico; known but undescribed taxa, taxa with unresolved taxonomy, and excluded species are also included. The main manuscript includes links to supplementary materials, including a reference list for Lepidoptera of North America north of Mexico, and a filterable spreadsheet with information on taxonomy, synonymy, size ranges of species, distribution by state, province, and country with references, and host-plant Family and Genus associations with references.

The similar species Diarsia esurialis has a forewing that is yellow, orange, or pink-lavender, often with the discal cell black between the discal spots (Powell and Opler 2009).

Shropshire and Tallamy (2025) provide a link to a supplemental filterable spreadsheet with information on host-plant Family and Genus associations with references for all Lepidoptera species of North America, north of Mexico.

The larvae feed on grasses (Powell and Opler 2009).