They've Got Gall

The oaks, that is. These strange growths all have something in common: they are galls produced by wasps. They come in all shapes, sizes and colors. All these galls came from one oak tree in our front yard. I love these tiny ones. Some look like sponges, crowns, urchins and even chocolate chips.

Growing in the tree they even resemble fruit.

Up close, they look more like tumors.

While I admire them , pick them off the ground, take pictures of them and watch Aidan pulverize them with his shoes, I will leave it to the experts to explain what galls are and how they are formed. Thank you Mr. Ed Perry, Farm Adviser, at UC Davis for this description:

The tiny gallwasp begins the gallmaking process in early spring by piercing a selected tree part with its egg laying device and depositing an egg inside the plant tissue. Fluids deposited with the egg cause the plant cell multiplication process to begin. The larva that hatches from the egg produces additional substances that maintain and control cell devision. The larva develops within a cavity inside the gall, feeding on material produced in the cavity lining. At maturity, the larva transforms into a pupa, and later becomes an adult that chews its way out of the gall. By causing the tree to form a gall, the gallwasp has provided food and shelter for its offspring.

It's amazing that a little bug I've never seen can provide so well for its offspring, all in one package, right in my own front yard and probably in your yard too. I feel a connection to these small creatures as I too try to provide for my young in the self-contained package we call home. The results aren't always pretty; somedays it's chocolate chips, but other days it's gnarly tumors.

There is so much more going on in the trees than I can fathom, and to think I once dismissed the galls as yard debris; but isn't there always so much more than meets the eye?


  1. Wow! I had no idea. Thanks for the way cool science lesson!

  2. Thanks for sharing this unique Fall beauty. A good reminder to look beyond what first meets the eye.

  3. Tracy HarrisOctober 23, 2007

    Wow, you learn something everyday! Thanks for the bit of knowledge!

  4. How did my offspring get so smart? Your thirst for knowledge is amazing. Keep teaching us!

  5. Is that what those things are? Cool! Carry on, Mama... creating that cozy little nest of yours :-) I think it must be a marvelous place to be!

  6. Good information!! Thanks for sharing.

  7. I never knew what those malformed tumerous bulbs were for. My kids loved crushing them with their heels as well. Thanks for the info Molly! Love it.

  8. We love these too. Jack always gets excited about the possibility of a somerthing living inside, like a little bug home.

  9. we have these on our oak trees, too. I love the analogy you've created with them. I'll never look at them the same way now....

  10. I don't think I've ever seen anything like that. My neighbor has a lovely oak that overhangs my yard. I'll have to see if we have any 'gall' ;).

    Thank you so much for that information and for the positive, upbeat post. It was definitely a nice change after what I've been getting in my inbox these days ;).

  11. So I was picking up galls, acorns and leaves in the backyard today and one more thing hit me about galls: the wasps are so smart, they get the tree to build a house for their young. We could learn a thing or two from insects.



email: mollydunham@sbcglobal.net
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