Andricus fecundator is a species of gall wasp in the Cynipidae family.
This small insect is similar to A. kollari, but is smaller, and forms a different gall. This species is found in woodlands where Oak is found, where it can lay it's eggs and produces it's galls where the buds should occur. The grubs live in the galls.
Artichoke Gall - http://www.flickr.com/photos/qwertyqwertyqwerty/