Fatal Metalmark
Calephelis nemesis
This male butterfly was photographed along the Agua Fria s. of Lake Pleasant, Arizona and is also hosted at Wikimedia.
This female was taking nectar at Sweet Bush (Bebbia juncea) and was observed at Camp Creek, Maricopa County, Arizona in September 2008. This specimen is very light and golden. Tom Horton informed me that this image is likely a female of the closely related Wright's Metal-Mark, Calephelis wrightii
Riodinidae -- Metalmark Family
By mid summer these small brown butterflies are common in riparian habitats of the Sonoran Desert where they actively seek nectar at flowers, especially the white blooms of Seep Baccharis (Baccharis glutinosa). This plant is also the host for the caterpillar stage. The wingspan is less than 2 cm. Many species of metalmarks are strikingly colored with various metalic hues; this species glistens metalic depending on the angle of view.