During a visit the day before, J showed me her lupine bush and asked me about these caterpillars. They totally grossed her out, because there were so many (~100?), all tangled in webbing. The best I could do on the spot was offer generalizations with comparisons to other gregarious and silky caterpillars, like
western tent caterpillars and
fall webworms. Curiosity got the better of me, so I asked her if I could take lupine clippings and caterpillars to raise, which
I like to do from time to time, to find out which kind of moth they turn into. I didn't really need to collect any, because a simple internet image search "caterpillar eats lupine" got me an easy answer when compared to my photos. Eh, the
adults don't excite me much; they're little brown jobs (LBJs) with
snouts. Both the common names,
Genista broom and
Sophora, come from other preferred legume host plants. A couple bloggers I follow have also featured the Genista broom moth:
Ohio Birds and Biodiversity (excellent comments about sightings) and
Bug Eric. It's interesting to note we're seeing local caterpillars in October, versus spring and summer elsewhere. As for the specific bush lupine, this is my best guess based on J telling me hers has both yellow and blue blooms like those at Asilomar, a characteristic that I believe is distinctive in yellow bush lupine populations along the coast. And, I believe this phenomena is different than just the normal flower color change from yellow to purple after being pollinated. Being the nice friend that I am, I clipped off the remaining caterpillars and bagged them to save J from the ick factor. Her bush lupine is now only 2/3 its former size. It'll be fine.
ps 03/20/14 - I noticed several moths have emerged. They're not much to look at, a medium-sized moth brown. I put both containers in the freezer. Am not sure what I'll do with them, but I'm done having them use up my best rearing containers over the winter. I didn't take any pictures, because they're really ugly to look at after 5 months of tangled and chewed, dried lupine stalks, numerous flat and felty cocoons attached to the rounded parts of the containers, and lots of dried poop and eclosion stains (forgot the name for this, but when leps emerge they release a liquid waste that's often reddish in color). J would be even more grossed out! I would like to practice dissecting, but I'm always reluctant to haul out my dissecting scope, because it takes up desk space that I usually reserve for piles of paperwork.
