I was examining
Rhopalomyia californica galls on coyote brush (
Baccharis pilularis) at the local salt marsh today, and noticed this gall with a large hole in it. I'm curious if anyone has ideas about what may have caused the large hole. Is it an exit hole from a parasitoid? A hole opened up by some predator hunting larvae?
The hole is about 1.8 mm in diameter. You can compare it size-wise to the
R. californica exuvia protruding from the gall in the lower righthand part of the image. I'll also upload crops of the large hole and the pupa.
Update: After bringing the gall home and examining it more carefully, I've revised the dimensions above, and have some additional images that I'll upload.
Later update: See also this additional set of images, which show an empty dipterid egg case, a leaf mine, and a brownish object (perhaps a pupa?) that I found on the leaves and stem at the base of this gall:
Still later update: Stuff has started emerging from the gall. See:
Still yet later update: I've gone ahead and cut the gall open to see what the inside looked like; see attached photos.