Insects are as a group complicated and mysterious. Everyone loves dragonflies. Butterflies have clubs and societies devoted to their protection. Gardens are designed just to attract them. There are t-shirts and even jewelry to honor them. Why every sighting seems to cause joy and excitement.
Oak Galls are amazing and mysterious—but for some reason nothing seems to be done in their honor.
This is not fair–and this is why. Oak galls are made by tiny creatures almost all of these are cynipid wasps. Just as there are different types of butterfly that will lay eggs on only a specific type of plant, different types of cynipid wasp that will only lay eggs on one type of oak. The tiny egg produces chemicals that cause the tree to produce the strange growths called galls. The galls are different for each type of tree. The larvae hatch inside the gall where they eat and live until they are mature and able to hatch, fly mate and start the process all over again.
The galls are hard to see until they fall to the ground. If this happens before the creature is mature the gall can be cut open to reveal the little larvae. Of course, then it will not become a wasp—but this might be ok—in the interest of science.
The larvae only eat inside the gall. They do not damage any more of the tree. In fact the tree is almost never harmed by galls. The adults are wasps, but they do not sting. The galls themselves can be beautiful like the oak plum galls which do indeed look like little fruits.
Gall formation is unpredictable. Some years there are a lot of them, other years very few.
All in all these are simply little creatures that happen to have developed an amazing way of protecting themselves as they grow to be adults.
Have you ever heard of anyone planting oak trees in hopes of attracting cynipid wasps—it is doubtful. There seem to be no societies to appreciate and protect them.
This needs to change. Look around for oak galls. Tell your children their wonderful and amazing life story. Now surely someone could design a great t-shirt!!
Pictures by Starla Willis