September 10th - The oaks on Brownhills Common are having a hard time this year. These colourful growths on their acorns are Knopper Galls: the abode of the gall wasp larvae. The adult wasp - a tiny little thing - drills into the acorn as it grows, and injects a chemical into the hole. This chemical causes a reaction in the acorn, and these colourful growths result. The larvae live inside the gall until spring, when they emerge.
Isn’t nature incredible?