Control and Eradication: When mites have been identified, appropriate control measures can be employed. A vacuum sweeper can be a valuable weapon in the mite control arsenal. Infestations of clover mites, rodent and bird mites in and around structures can sometimes be eliminated by vacuuming alone. Vacuuming may be less effective, but still of value, in controlling various food mites, straw itch mites and dust mites. Note that dust mites are not prevalent in ductwork; therefore, duct cleaning is not recommended for dust mite control. However, a high-efficiency particulate air (HEPA) filter can be installed to help prevent airborne allergens, including dust mite particles.
Moisture control also can be important. Mites transfer air and water through their body walls and are subject to desiccation at low humidity. Dust mite populations, for example, suffer when a relative humidity of 50 percent or less is maintained. On the other hand, high humidity can cause mite populations to increase exponentially.
Well-ventilated homes in dry climates contain few dust mites. Homes with a relative humidity that consistently rises above 50 percent can contain more than 100 dust mites per gram of dust. To reduce dust mite numbers, a relative humidity of less than 50 percent must be maintained for several weeks. Any fluctuation in humidity, however brief, seems sufficient for dust mites to remain and reproduce. Daily activities such as air-conditioning and showering, will cause humidity levels to fluctuate in portions of the home. Thus, other means of controlling dust mites should be employed in addition to humidity control.
For dust mites, products containing benzyl benzoate, and possibly abrasive dust formulations, may provide some control when applied to flooring and floor coverings. Bedding, draperies, floor coverings and furniture should be cleaned regularly. Pillows, mattresses and upholstered furniture can be discarded or sealed in plastic covers to help prevent dust mite infestation, and to reduce ongoing infestations and their associated allergens. Persons suffering from allergic reactions or asthma should consult a physician.
Exclusion methods also can be used for certain mites, e.g., clover mites. Structural entry points, e.g., gaps in and around foundations, doors, windows, vents, utility lines, etc., should be sealed. This will help to keep clover mites outdoors along with rats, mice, birds -- and the mites these pests bring when they are allowed to nest in structures. If nests are found, they should be removed and the area around them vacuumed. Other non-chemical methods include maintaining a plant-free border around foundations and reducing the amount of fertilizer applied to lawns – both of which help to keep clover mites away from structures.
Pesticides labeled for use against mites, known as miticides or acaricides, can be effective against clover mites and chiggers in grassy areas. For chiggers, however, insect repellents containing 7 percent to 30 percent “DEET” should be used as the first line of defense. To dislodge any chiggers that may have attached, take a hot, soapy bath or shower immediately after visiting natural areas where chiggers are present.
Images courtesy of the US Centers for Disease Control and Prevention, Wikimedia Commons, and other university websites.