Tharsalea arota arota

Tailed Copper

Tharsalea arota arota - the Tailed Copper - is a beautiful summer butterfly that can be active into the heat of August some years. Males emerge first, usually in June, and stake out territory as they await females. They perch on trees or shrubs and can easily be found as they fly off to investigate possible females, then return to favored spots, often along a trail. In my experience, females are best sought for on the host currant shrubs about a month after the males have begun flying.

Nominate arota can be found in scattered colonies from San Diego County all the way up to the Sierras. The scarce subspecies nubila occupies a relatively small (and possibly shrinking) range in the Santa Monica Mountains and perhaps east towards Mt. Wilson in the San Gabriels (Griffith Park is the type locality). Most if not all of the colonies in the San Gabriels are nominate arota, as are those in the San Bernardinos.

This copper is single brooded, with larval development occurring before flights (April-July depending on elevation); they overwinter in the egg. Only this species of copper uses plants from the Glossulariaceae family as their host.