LINCOLN, Neb. -- A tiny mite, aptly called an "itch mite," is responsible for the mysterious, itchy red bites reported by a number of eastern Nebraska residents recently, University of Nebraska entomologists say.

University entomologists worked with the Nebraska Department of Health and Human Services, Lincoln/Lancaster County Health Department, U.S. Department of Agriculture/Agricultural Research Service and entomologists from Kansas State University who are collaborating with the Centers for Disease Control and Prevention to identify the culprit, said David Keith, a university urban integrated pest management specialist.

The Pyemotes mite is preying on small fly maggots that cause the "leaf edge" galls on pin oak leaves, Keith said. The galls on pin oak leaves are unusually abundant this year and in many cases the maggots that caused the galls have matured and are emerging in the millions and dropping to the ground.

"These are harmless, but in examining empty galls, in which one or more maggots were killed, large numbers of the itch mites, a predator of the maggots, were found," the Institute of Agriculture and Natural Resources specialist said. "These microscopic mites, carried by the wind, are tiny enough to penetrate the mesh of a standard window screen and may be completely overlooked because of their very small size."

People sleeping with windows open could easily be bitten at night, giving the impression that something is infesting the bedroom.

"Every fall we seem to get complaints about insect and mite bites, but this year it is quite different," he said. "Although all the 'regulars' that we normally expect, such as cat fleas, pirate bugs, chiggers, mosquitoes and others are out there and doing their share, something else is involved this time."

The mites have been reported in several eastern Nebraska communities, but Lincoln seems to have been hardest hit. The mystery bites are being reported mostly by people who spend time outdoors, but also from others who remain indoors.

No one is seeing insects or associating them with these lesions, but several have reported they were working outdoors, and often standing in the shade of pin oak trees.

Keith recommends people keep windows closed and limit outdoor activity until the problem subsides, which should occur in the next seven to 10 days, he said.

"If you have to work outside, when you come back indoors, be sure to take a hot shower, lathering generously," he said.

Also, be sure to launder clothing after wearing -- "don't reuse yesterday's shirt," Keith said.

To reduce itching, apply calamine lotion, hydrocortisone cream or an antihistamine cream, such as Benadryl cream.

Also, wash the bites often with soap and use an antiseptic or antibiotic ointment to keep the wounds clean and promote healing.

"It's also important not to scratch," Keith said. "The bites are intensely itchy, but scratching provides little relief and actually causes pain and tenderness."

The bites don't hurt when they occur, but after a bite one or more red spots usually appears. The red spots vary in size from one-fourth to one inch in diameter. In the middle of the red spot is a small, raised "pimple" or blister, Keith said.

Most bites occur on the upper torso, abdomen, back and neck, shoulders and arms. With most people there are no apparent secondary effects, but some people have reported headache, fever, nausea or asthmatic symptoms.

Unlike chigger bites, these do not seem confined to ankles, feet, legs and the belt line, he said.

Some bites are quite small, but some may be as large as a quarter and each has a raised center which may take the form of a small watery blister.

The itch mite bites may occur in clusters, forming a rash which may last for several days.

Source: David Keith, Ph.D., Professor, UNL Dept. of Entomology, (402) 472-8918
Writer: Sandi S. Alswager, IANR News Service, (402) 472-3030