What's That Bug? does not endorse extermination

Subject: Brown Moth Attack!
Location: San Francisco Bay Area
October 14, 2013 6:55 pm
Hello Bugman,
Lately, my school and my house have been infested with these interesting small brown moths. They are around two centimeters wide resting and have feathery antennae. I have looked on the internet and can’t figure out what they are! There are thousands of them all over the oak trees. Please help me solve this mystery!
Signature: Sidney

California Oak Moth

California Oak Moth

Hi Sidney,
Thank you for including the information about the oak trees, as that helped us to quickly locate the identity of the California Oak Moth,
Phryganidia californica, by matching to this photo on BugGuide.  Only the males have the feathery antennae.  According to BugGuide, there are:  “Two generations per year in northern California; sometimes a third generation in southern California. Overwinters as a larva on underside of oak leaf. Populations are cyclic: larvae are common in some years, and virtually absent in others.”  The caterpillar is known as the California Oakworm, and according to the UC Davis Integrated Pest Management System:  “The California oakworm (Phryganidia californica, family Dioptidae) is one of many species of caterpillars that feeds on oaks. It is the most important oak-feeding caterpillar throughout its range, which extends along the coast and through the coastal mountains of California. Damage is most common on coast live oak (Quercus agrifolia) in the San Francisco Bay and Monterey Bay regions. Populations vary unpredictably year to year from very high to undetectably low. Healthy oaks generally tolerate extensive loss of leaves (defoliation) without serious harm, so treatment to control oakworms usually is not recommended.”  This must be one of those plentiful years.

California Oak Moth

California Oak Moth

Thank you so much!! 🙂
Sidneh

What's That Bug? does not endorse extermination
Location: San Francisco, California

Leave a Reply

Your email address will not be published. Required fields are marked *