The blues in your photographs are all the “Bernardino” Square-spotted Blue (Euphilotes battoides bernardino). Recently, according to many butterfly authorities, this butterfly should be considered as full species, the Bernardino Blue (Euphilotes bernardino) which is found throughout southern California and western Arizona where its food plant the California Buckwheat occurs. There are several forms of Dotted Blue (Euplilotes enoptes) which occur in southern California, including one which can be found in the nearby San Gabriel Mountains and it feeds on Naked Buckwheat (Eriogonum nudum). Although it was not listed in the 1977 The Butterflies of Orange County by Larry Orsak (out of print), I recent list I’ve seen has it listed. Since E. nudum isn’t found in Orange Co., I doubt the butterfly occurs. In addition, this butterfly looks very different from the Bernardino Blue with much smaller spots.
All of the buckwheat blues stay very close to their food plant and usually nectar on it as well as mate and the female lay eggs on it. Thus there is good chance if you are looking at a buckwheat blue on California Buckwheat it is a Bernardino Blue. The Acmon Blue has a similar pattern with black spots and orange on the hind wing and could be found nectaring on California Buckwheat (lots of butterfly species can’t resist), but it is different enough (larger, paler blue above and with iridescent hind wing marginal spots) that it should be mistaken for a buckwheat blue.

—–Best regards, Fred Heath
( Author of An Introduction Southern California Butterflies )