September 09, 2005
They're Back Itch Mites on the Increase
LINCOLN, Neb. Itch mites those tiny insects that bit hundreds of southeast Nebraskans last fall are back and are likely to be a problem again this fall.
Several Lincoln residents reported itchy, red bites after being outdoors over Labor Day weekend, said Jim Kalisch, University of Nebraska-Lincoln insect diagnostician.
UNL entomologists have been monitoring itch mite numbers this summer using sticky traps. The last sticky trap check revealed significantly more mites.
"Itch mites are emerging now in high numbers in some Lincoln and southeast Nebraska neighborhoods, especially those which have extensive plantings of mature pin and red oaks," Kalisch said.
Itch mites, tiny creatures associated with galls on the leaves of pin and red oaks, usually bite people's upper torsos, necks and arms, said Dave Keith, urban integrated pest management specialist in the university's Institute of Agriculture and Natural Resources.
"As in 2004, this summer we once again have an abundant crop of leaf edge galls and itch mites, the latter feeding on the midge larvae, or maggots living in the galls," Keith said.
Just because the itch mites are back doesn't mean people must stay indoors, Keith said.
"Visit with your neighbors and check the lower leaves of pin oak, red oak or black oak trees in your neighborhood to see if leaf edge galls are abundant," he said.
The galls are easy to spot, Keith said.
"Just look for the thickenings of the leaf margins, usually found in the notches of the leaves," he said. "In some trees, the galls are so numerous that the leaves are twisted and disfigured. If you have few or no galls, you may not have a problem, but remember that during mite showers the mites can be blown to your property from surrounding trees."
Mite showers occur when thousands of mites emerge from galls and either drop to the ground or become airborne on wind currents, Keith said.
People who are bitten can expect symptoms within four to six hours. Bites are red, from one-fourth to three-quarters of an inch in diameter, with a hard, raised pimple in the middle. Bites are intensely itchy, but scratching offers little relief and is painful.
"The bites are irritating, not life threatening, although a few sensitive individuals with large numbers of bites, 100 or more, have been hospitalized briefly," Keith said. "A few bites have about the same effect as the same number of mosquito bites."
Itch mites don't transmit disease. Bites usually heal in about 10 days if they are properly treated and not scratched.
To treat bites, use calamine lotion, an antihistamine cream, such as Benadryl, or a hydrocortisone cream to reduce itching. Wash the site often with soap and use an antiseptic or antibiotic ointment to keep the wound clean and promote healing.
UNL entomologists believe that the mites disperse from trees during evening hours, and that they are not as active during the day.
"This suggests that outdoor work activities from morning into the afternoon are much less risky for getting bitten," Keith said. "However, we don't want people to get excited. We do not recommend tree removal, spraying of oak trees to prevent midge galls or spraying lawns for mites." No insecticides are available to control the mites.
"Remember, many other types of critters, such as mosquitoes, chiggers, fleas and black flies, also can bite you and cause red, itching welts," Keith said.
University entomologists make these recommendations:
Continue normal outdoor activity during the day. Keep an eye out for leaf edge galls on pin oaks, red oaks and black oaks and watch closely for bites.
Plan to take a warm shower and lather well after being outside working, playing or sitting under or been near a pin oak, red oak or black oak tree, especially during the evening. Burr oaks are not affected by this gall insect and do not generate mites.
Wear an insect repellent, but do not use on children under 3 years. Check the label and follow directions for use. Keith said some people claim sun screen helps reduce bites.
When returning indoors, remove and launder clothing. Mites are tiny and not readily visible and are small enough to penetrate the weave of most fabrics.
Dont handle grass clippings or oak leaves with bare hands.
For more information about itch mites, consult UNL Extension NebFact, NF05-563, Pyemotes Itch Mites, available from local extension offices or on the Web.
9/9/05-SAK David Keith - Ph.D.
Entomology Professor (402) 472-8918
 
Jim Kalisch
Entomology Entomology Technician (402) 472-8691
Sandi Alswager Karstens IANR News and Photography (402) 472-3030
Department:
Entomology
|
