This is a fairly common copper that flies in multiple broods from April to October depending on location. Hosts include members of the Polygonaceae including species of Rumex such as salicifolius, triangulivalvis, hymenosepalus, and fueginus. They also use knotweeds Polygonum spp. and also common knotweed, Persicaria lapathifolia. Males and females differ dramatically in coloration, but both are handsome butterflies. A reliable spot for these for me has been Trout Pond Trailhead at Cuyamaca Lake in the late summer/early fall.
A female Purplish Copper - Lycaena helloides - from a creek-side area not far from where highway 74 meets the 371 in Riverside Co. This and the following three shots were taken August 3rd and 4th, 2011.
This is a male Purplish Copper - Lycaena helloides - at an excellent place to find them: the Trout Pond Trailhead, Lake Cuyamaca, San Diego Co., October 6, 2007.
A female Purplish Copper, at the same spot around Lake Cuyamaca, October 6, 2007.
One more male, same place on August 25, 2007.
Male, same place on October 6, 2007. This looks like a non-native knotweed (Polygonum aviculare?) to me.
A Purplish Copper had recently emerged, leaving this pupal skin behind on a dock plant. Riverside Co. near Keen Camp, August 4, 2011.
The original description by Boisduval in 1852. Lorquin had would have collected helloides in San Francisco in 1850/1851 and sent those specimens to Boisduval in Paris.