Mighty small mites around the Midwest and KC region leave nasty, itchy bites | The Kansas City Star

“She looked like she had been in a boxing match,” Koranda said.

The family pediatrician said he was 99 percent sure that the welt came from a chigger or insect bite.

Later Koranda, the Kansas Public Radio statehouse bureau chief in Topeka — who also had been scratching some apparent insect bites on the back of his knees — kept noticing online stories about the oak leaf itch mite, a microscopic arachnid whose bite is not noticeable but still leaves a nasty red mark or welt that will show up about a day later.

Then he remembered how, several days before, he had taken his daughter on a walk down a street lined with trees.

Oak trees.

“Then I put it together,” Koranda said.

With that Koranda and his daughter — who’s all better now — joined many across the Kansas City region this fall in being victims of the oak leaf itch mite, all scratching bites they had no memories of receiving.

The Kansas State Extension office in Olathe has fielded its highest number of mite-related calls in 10 years, said Dennis Patton, horticulture agent.

“It’s just the year,” added Bob Bauernfeind, Kansas State University entomologist in Manhattan. “The mites were big in 2004 and 2005, and then there were nine years in between with not a peep about them.”

The oak leaf itch mite — Pyemotes herfsi, first identified just a decade ago — hangs around gall formations established on tree leaves by insects such as midges. The midges will lay eggs in the gall formations.

“This year we have had a spike in the number of these gall formations,” said Patton.

The mites, meanwhile, feed on the insects in these gall formations. The microscopic mites, entomologist say, hold down the number of midge larvae. And because the mites are protected inside the galls, spraying trees with a pesticide won’t get rid of them.

With the coming of cooler temperatures and shorter days, the mites have been exiting the galls, Patton said. When the mites hatch, in just one day a tree could shed more than 370,000, entomologists say.

Anyone under or near one of these trees, or even downwind from them, likely has been visited by the mites — which are almost microscopic at just .2 millimeters in size.

Routinely their bites will leave persistently itchy red marks, sometimes with a fluid-filled center. The bites, while annoying, usually are not considered dangerous. The bigger risk is secondary infection caused by scratching, something both adults and children can find difficult to resist.

Dermatologists at Children’s Mercy Hospital are reporting no uptick in such bites, a spokeswoman said.

School nurses in the Blue Valley School District, however, have been supplied with mite-bite information.

Although the district does not formally track such bites, the district’s nursing coordinator has reported a “slight increase” in the number of students reporting itch bites, said Kaci Brutto, distict spokeswoman.

Over-the-counter bug repellants are not effective with the mites, Patton said. The smarter strategy is to limit exposure, such as wearing long-sleeve shirts and long pants.

Those who believe they might have been exposed should take a shower using a sponge and washcloth, and then put their clothes into the laundry.

Patton recommends calamine lotion or cortisone cream to help sooth the itch impulse.

Two hard freezes, he added, should bring an end to the oak leaf itch mite invasion of 2015.

For Koranda, the next time he takes his daughter for a walk, “I will wear long pants.”