The eggs are laid in groups of 2 to 4 under the host plant leaves. The eggs hatch in 7 to 8 days and after hatching, they feed on the underside of the leaves on the host plant. Caterpillars in Colorado and Wyoming are reddish brown with red spines, with third or fourth instars hibernating. The caterpillars feed on Viola species and willows. The caterpillars can be found from April to June. The caterpillars are silver gray with white dots.
