I was walking down the street and saw this plant and was sort of baffled by it. Have I seen this before? Maybe? Anyway, I took some pictures and googled around.
So, these are caused by aphids. They are eating the leaves and cause the leaves to create this redish gall around the aphids. I’m still sort of having trouble picturing exactly what is happening here but the link above has a pic of a manzanita gall cut open and filled with aphids. I never took the Pests class at Merritt and clearly I should have!
