...is a true monophage on Isocoma acradenia (E. Greene) E. Greene on which it produces two annual generations, one florivorous which alternates with a longer generation that spends most of the winter, spring, and summer ....inside a slowly developing ....gall.

...each gall represented a foreshortened axillary branch circumscribed by up to 20 ranks of scale-like, lanceolate, entire-margined leaves demarking stunted internodes... Procecidochares blanci is a bivoltine, circumnatal species.... on Isocoma acradenia in southern California....until January when larval eclosion and gall initiation coincide with axillary bud growth stimulated by the resumption of winter rainfall...

[photos of gallicolous generation at https://www.biodiversitylibrary.org/page/16178092#page/70/mode/1up]