Perched on flowers of
Plectritis macrocera near ridgetop in mixed Oak Woodland/Chaparral in an area of serpentine substrate.
Initially I narrowed this down to one of three species:
Adela thorpella, A. oplerella or
A. flammeusella. These species are discussed on pg 40 of Powell & Opler
(1).
According to the info there,
A. oplerella is known only from a few serpentine locales in the San Francisco Bay area. That fit well and sounded intriguing. But reading further, it turns out
A. oplerella has small eyes, and antennae equal or shorter than FW. So that seems to eliminate it here.
Next I looked at the images of
A. flammeusella and
A. thorpella on BugGuide. All the images of
A. flammeusella had three large, distinctive, white spots on each forewing (as does the
image from Powell & Opler(1)). The color and markings of the image of
A. thorpella seemed to fit my moth better...and that BugGuide post was shot at a relatively nearby locality (Mt. Hamilton).
However, two things prompted me to reconsider
A. flammuesella over
A. thorpella. First, the host plants for
A. flammeusella (namely, species of
Orthocarpus/Castilleja) were more likely to be nearby to where I shot the photo than the host plant of
A. thorpella (
Platystemon californicus)...though the latter might be present as well. Second, in reference to the white wing-spots of
A. flammeusella, Powell & Opler state that "both sexes, especially females, have reduced or lack markings in some populations". So the lack of conspicuous forewing spots on my moth wouldn't necessarily eliminate the possibility of
A. flammeusella.
In the end though, I decided to go with
A. thorpella because Powell & Opler also state that, in contrast to
A. flammeusella "...
A. thorpella has shorter antennae (2.5 X FW length in males)..." And, using photoshop tools, I measured the antennae length of my moth here to be less than 2 X FW length.
As always, I welcome and appreciate any comments, corrections, or confirmations here.