Oak Itch Mite
The oak itch mite is a pest to humans, not plants. A nearly microscopic mite, oak itch mites fall from pin oak trees starting in July through leaf drop in the fall. Raking oak leaves in autumn can also expose us to these mites. The oak itch mites bite and cause red chigger-like bumps and rashes. The bites can be distinguished from chigger bites since they are on the upper half of the body where the mites land after raining down from above. These mites feed on the larva of the oak marginal leaf fold gall and only bite humans incidentally when they fall from the tree. They start feeding in July and have one generation every 7 days. The females then lay up to 200 eggs, leading to a huge boom in the population. Any pin oak tree that has lots of oak marginal leaf fold galls can be a host. They are less often found on other red oaks.
Controlling this mite is nearly impossible since it hides in the marginal galls. This makes spraying ineffective. Since they are mites, DEET also doesn’t repel them. The best strategy is never to spend time under oaks with marginal galls and wear protective clothing. Wearing gloves and long sleeves while raking pin oak leaves in the fall is also recommended, as is taking a bath afterward and washing all clothes. One product that may reduce their numbers is Tanglefoot. It is a sticky substance that can be applied around the tree’s trunk in a 2-inch band. This sticky band catches the mites early in the year when they try to crawl up to the marginal galls to start feeding, breaking their life cycle.