The Larva of the California Tortoise Shell Butterfly feeds on Ceanothus plants. There are over 50 species of Ceanothus found in California. They range in size from two foot anywhere to twenty foot and have flowers anywhere from white, to blue, to lavender. One of this plants common names is wild lilac. It is also evergreen making it an excellent garden plant!
The California Tortoise Shell
has large fluctuations in population. Some years there is a huge burst in population ans in some there are very few to be seen. In years where the populations are greater there is more migration and these butterflies can be found in the mountains and northern portions of California.