California, Compton, and Milbert’s Tortoishells can be found in our area and are generally smaller than the Mourning Cloak. The California’s brightly colored dorsal (upper) side of the wings is opposite to their ventral (under) side, which looks more like a dead leaf. The ventral side can look similar to a Comma’s but they lack the white “comma” on the hindwing or the sharp “ins and outs” along the wing edges. Caterpillars feed on various species of wild lilac (Ceanothus). California tortoiseshells stick mainly to the west, but sometimes stray to the midwest and east after population irruptions.
Size: Wingspan 1 1/4 – 2 3/4 inches (3.2 – 7 cm)
Photo by: Kristi DuBois on 3/27/22 in Mineral County, MT