Found in association with black-crowned Adelids presumed to be A. trigrapha. This type has shorter antennae (about 1.5X wing length instead of 2.5X) and a red-orange crown; I do not discern any difference in the width of the forewing stripes. The red morph was also less abundant than the black, maybe about 1/5 of the large number that were present that day. Also, the black-crowned's were actively nectaring on newly opened Linanthus, while the red-heads seemed content to rest with wings folded, on blades of grass.
Either we have two moths here or the species is gender dimorphic.