This fall, many mid-Missouri residents found that raking the colorful abundance of leaves that flooded their yards left them with more than just a clean lawn. In fact, some were surprised to find dozens of itchy chigger-like bites around their neck, face and upper torso areas. This was the byproduct of coming into contact with a nearly microscopic mite known as the oak mite.
Originally recognized in 2004 after a major outbreak in Kansas, this microscopic mite was reported to reach outbreak levels in 2004-2006 in other Midwest states as well, including Nebraska, Texas and Missouri. Since then, the level of activity had been low, until this year.
“They are always around,” said MU Entomologist Richard Houseman. “Though in some years they may have peaked and you’ll have higher numbers. It usually depends on whether there is some abundant insect prey, and for oaks that is usually gall minges.”
Oak mites are known to prey on small fly midge larvae that form in the marginal fold galls of pin oak leaves. When these gall larvae drop to the soil in early fall to pupate for the winter, a huge number of the oak mites often fall with them.
“They are a unique insect,” Houseman said. “An adult female has an egg sack that develops right on their bodies and becomes five to 10 times their body size. So you have a single female off the end of a huge, round spherical egg sack, and when the eggs hatch the young will actually wait on the outside of the egg sack to mate with their siblings.”
Many entomologists estimate up to 300 mites can develop from a single female egg sack, and according to research at the University of Nebraska, approximately 16,000 adult female oak mites can emerge from one infected oak leaf. This could potentially leave the poor soul who just dived into or started raking the infected pile of leaves with hundreds of chances to wake up with red welts around the upper parts of their body.
“We are not their regular prey,” Houseman said. “They have a mouth part that’s like a little tube that they jab into their insect prey and when they jab into us, it often leaves some enzymes in our skins that our body starts to react to”.
There are many safe ways to prevent and control these itchy pests:
- Pay attention to media sources such as; radio, newspapers, and local news from T.V. and internet for news about local outbreaks.
- Keep a look out for bites around mid-summer to fall.
- Remember to keep windows shut during “mite shower” months (August- Mid October) if your home is located in a high marginal oak leaf gall area.
- Wear clothing that covers most areas of the body.
- If you get bitten, apply topical lotions such as Benadryl or calamine lotion, but refrain from excess scratching as it can often lead to more serious infections.
If you notice the area around your oak trees becomes infested due to “mite showers” there are many insecticides that can also be used to reduce the numbers of these itchy pests. For a list of these products go to: www.kellysolutions.com/ne/.