Hi this is eating a native live oak in San Francisco, and has nearly defoliated the entire large tree. Incidentally, it is causing a lot of mess for the building owner who is really frustrated. I have suggested Bt, but its a really big tree and would probably require professional spray equipment.
I am not sure these are all the same sp., but perhaps you will know.
Thanks for looking.
You appear to have an infestation of the California oakworm, Phryganidia californica, (Lepidoptera: Dioptidae). see https://ipm.ucanr.edu/PMG/PESTNOTES/pn7422.html for more detailed information.
Wow. Thank you so much!
It sounds like a significant infestation. Professional treatment with Bt using proper equipment is the best approach for a tree that size; I recommend consulting an arborist for an effective solution.
