Oh my... What big balls you have!

I recently signed up to a gardening newsgroup "rec.gardens" and I posted the same question on there and this is one of the replies I got.

"These are galls, sometimes called "oak apples".

They are caused when an insect lays an egg inside the fresh, young tissues of the tree. The larva that hatches causes an irritation that causes the tissues to swell. The larva then eats out some (not always all) of the excess tissues.

When the larva matures and forms an adult insect, it bores its way out of the gall. The galls you show in the image will eventually turn black and fall from the tree. They will be very light in weight with a corky internal texture.

These galls are generally quite harmless to the tree, although cleaning them up from driveways and lawns can be a bother. Other galls (but not these spherical ones) can be symptoms of disease, which can cause serious damage to a plant.

During colonial times, these galls were gathered and boiled to extract tannic acid for making ink and dyes and for tanning leather."


So, there... Apparently they're "Oak Apples" and they will hatch into some freaky bugs of some sort... *SHUDDER* That makes me feel just freaking WONDERFUL about going out in my yard. Dontcha think!? (sarcasm sarcasm)