Glaucopsyche piasus excubita
Bush Lupine Arrowhead Blue
This subspecies gets into southern California in Kern County along the east slopes of the Sierra Nevada at lower elevations. They range from around Bishop south to the Tehachapis. Named in the 1998 Systematics book along with umbrosa and gabrielina, it is distinguished from nominate piasus by its greater ventral contrast and smaller size. Through most of its range it uses Lupinus excubitus, and like the other arrowhead blues it has a single flight (from late March to late June) and overwinters as a chrysalis.
I saw just this single Glaucopsyche piasus excubita flying around the lupines down Kelso Valley Road in this very dry year. I've only visited this part of Kern County a couple of times, and each time I've seen several species of blue on these lupines (just under a mile south of the intersection with Piute Mountain Road). But this is the first time I've seen this one, the one I've most wanted to see. April 7, 2014.
A week later than the above, I tried the Kern River Valley area and found Glaucopsyche piasus excubita in good numbers among the lupines along the Whiskey Flat Trail. Finding the right spot makes all the difference. April 13, 2014.
A female Glaucopsyche piasus excubita ovipositing on host Lupinus excubitus. Whiskey Flat Trail, April 13, 2014.
Dorsal view of a female Glaucopsyche piasus excubita. Whiskey Flat Trail, April 13, 2014.