Oak Galls

Day 183: On the prairies of southwest Washington, apples grow on oak trees. Oak apples (also known as oak galls) form when a tiny wasp lays an egg on the host species. As the larvae develop, they feed on the plant tissues within the protective skin of the gall. Various species of gall wasp utilize Garry Oak (Quercus garryana) in this manner, with size of the gall and internal characteristics often providing a clue as to the wasp's species. These were well out of reach, so I did not examine the internal structure. And yes, I did consider pasting a "censored" sticker over the one on the top left. Nasty little wasp!