A Rose (gall), by any other name...

​Last week, while doing a plant survey I came across something extraordinary and weird on a native rose bush. It appeared to be growing out of the leaves. It was hard and globular with spikes but the spikes were actually soft to the touch. Surely this was some sort of gall but what kind of crazy creature could create such a thing!?

Being an intrepid scientists, Dianne (an environmental educator on the sunshine coast) and I were eager to slice the galls open to see who was living inside. Not going to lie, I imagined poking one of these with a knife, hearing a popping noise and having a bunch of maggot-like critters explode onto my lap. Instead, the galls were dense. Inside there were a few pockets like cubby holes, and in each - a curled up, scared little larvae. These larvae wriggled  and thrashed when disturbed

So who are these mysterious creatures? With a bit of research and the keen eye of my classmate Dan, we discovered that these are the larvae of a cynipid wasp of the family Dipolepsis. The wasps lay their eggs on the rose and rather than the larvae chewing their way through the leaves the induce growth in the rose to create the gall - a continuous food source. When mature, the wasps emerge from the gall.

​Anyone else seen these galls around the Squamish area?