One of the many joys of early spring is opening the windows and letting fresh air into the home. However, warm spring air is not all that is coming in lately.

Many homeowners are frustrated by a little visitor called the winter grain mite. As the name implies, these mites are small but can be obnoxious.

Winter grain mites are commonly found in the wheat fields of Kansas. However, because their food source becomes scarce during the winter months, they moved last fall into our Kentucky bluegrass, perennial ryegrass and tall fescue lawns. Now that the temperatures are warming, they are on the move once again.

The young mites are reddish-orange but become black with reddish legs as they mature. This turf pest is unique in that it feeds during the winter to early spring and spends the summer in the egg stage.

Damage often appears from January through mid-March and is evidenced by a silvery, scorched appearance to the turf. Mites feed on cloudy days or at night.

On sunny days the mites can be found on the crown of grass plants or in the thatch layer. They feed by rasping the leaf surface and sucking the released plant sap. The silvery effect is caused by the loss of chlorophyll and plant sap.

Unfortunately, the mites are not harmed by short periods of sleet, ice or frozen ground. In fact, they can actively feed under snow.

These normally outdoor pests become an even bigger problem when they move indoors often by accident. They climb through open windows and around doors to find their way inside.

The mites do not cause harm or bite but are considered a nuisance because of their numbers and the red spots they leave when smashed.

Although mites that are indoors can be killed with aerosol sprays containing pyrethrum or allethrin, there is no residual effect so several applications will have to be made.

Household insecticides containing resmethrin or premium-grade malathion have a longer residual effect. Spray these around doors, windows and other areas where mites enter to reduce the number of mites in the home.

Bruce Chladny is horticulture agent at K-State Research and Extension-Douglas County. For more information, call him at 843-7058 from 8 a.m. to 5 p.m. weekdays.