Archive for Saturday, January 8, 2005

Texas bites linked to tiny mites that troubled Kansas, Midwest

Straw itch mite may be making appearance in Lone Star State

January 8, 2005


— Dewey and Bette Garner believe their West Texas pecan grove may be producing more than just pecans -- it also seems to be the source of itchy, red bumps covering Dewey's upper torso and neck.

"We decided pecans were not the thing to have," said Bette Garner, explaining that the bumps first arose shortly after her husband raked leaves near their new retirement home at Clyde last fall. A dermatologist told the Garners that bug bites were to blame.

Texas Cooperative Extension entomologist Michael Merchant said Garner might be getting attacked by Pyemotes mites, tiny eight-legged predators that plagued Kansas, Nebraska and Missouri last year.

The mites have been confirmed in the Dallas area, where residents report being bitten while raking leaves.

The unusual Texas outbreak may be linked to a particular species of the itch mite that made its first verified appearance in the United States last year, said Kansas State University researcher Alberto Broce. Investigators believe wet weather may be increasing the Pyemotes' population.

"I've talked to several people in Dallas, and the bites are very similar to what we have in the Midwest," Broce said.

For most people, the bites are nothing more than a minor irritant, although a Garland man suffered an allergic reaction and had to be taken to an emergency room after being bitten while raking leaves, said Merchant, who is based in Dallas. Pyemotes feed on insects that eat leaves.

"Their biting on humans is accidental or incidental to what they normally do for a living," he said.

Merchant said Pyemotes mites were extremely small and of the same genus as the straw itch mite, which is well known to farmers.

The straw itch mites are common in grain storage bins and feed on moths and caterpillars. People are occasionally bitten when cleaning out infested bins.

"You don't very often get a new pest that no one recognized before as a pest, and that's what seems to be going on right now," Merchant said. "Entomologists are beginning to realize that one of these pests is potentially a human biting pest, and it may explain some previously unexplained bites that people get outside."

The Dallas mites may belong to the same species of Pyemotes found to be the source of mysterious bug bites in the Midwest last year. Those mites made headlines after hundreds of bites were reported in Pittsburg, Kan., and Lincoln, Neb.

Florida entomologist Cal Wellbourn later identified the genus and species as Pyemotes herfsi. Broce said verification of the Central European variety was the first confirmation of its presence in the United States.

More sampling will be needed to confirm that the Texas mites are from that species, Broce said. Researchers say they fit the same profile.

A hard freeze eradicates the bugs, but Broce said he had no idea whether the troublesome mites would return in strong numbers later this year.

Repellents based on DEET provide protection from Pyemotes bites. A change of clothing and a hot, soapy shower after working out of doors -- especially around oak trees -- should help reduce the incidence of the bites, Broce said. Spraying insecticides does not appear to help.

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