Callophrys siva near chalcosiva (San Bernardino Mtns.)
This butterfly can look very much like nelsoni, but they tend to be more boldly marked. The host is Western Juniper, Juniperus occidentalis, while nelsoni uses Incense Cedar as host. At Onyx Summit and along the Sugarloaf Trail down to Wildhorse Meadows, this butterfly can be easily found taking nectar on flowers. Thanks to John F. Emmel for help with this butterfly. Dr. Emmel says some specimens of this butterfly show intergradation with nelsoni. Perhaps what we're witnessing is an early stage of speciation, with one entity adapted to juniper and showing slightly bolder markings than the closely-related entity nearby adapted to Incense Cedar. Emmel says of near chalcosiva:
They occur in areas of Juniperus occidentalis in the San Bernardino Mts., southern Sierra Nevada around Kennedy Meadows, Loon Lake area west of Lake Tahoe, and in large stands of J. occidentalis in Lassen and Modoc counties. There is Calocedrus nearby these stands, and in those Calocedrus areas you get the typical nelsoni phenotype. Some of the specimens from Onyx Summit show intergradation between the two entities. Likewise in Modoc County the two hosts can be intimately sympatric and have the whole gamut of underside pattern from nelsoni to chalcosiva. I have beaten larvae from Juniperus occidentalis in Modoc County which were typical "near chalcosiva". (Pers. comm.)
These overwinter as papae in the ground litter beneath the host Junipers. Larvae eat fresh growth.