

GAINESVILLE—When it comes to creepy-crawly insect pests that thrive in warm weather, the tiny, almost invisible dust mite can cause big problems around the home, especially for allergy sufferers.
“Just thinking about a dust mite is enough to give you the heebie-jeebies,” said Phil Koehler, urban entomologist with the University of Florida’s Institute of Food and Agricultural Sciences. “For some people — especially clean freaks — finding out you’ve got dust mites living all around you can ruin your whole day. Worse yet, you may be inhaling droppings of the dust mite.
“These microscopic scavengers, which feed on skin shed by people and pets, are invisible to the naked eye but the dust mite can be found even in the cleanest homes,” he said. “A gram of dust may contain up to 4,800 dust mites, and an ounce of dust may host 136,000 or more dust mites.”
Koehler said dust mites can inhabit mattresses, pillows, blankets, quilts, carpets and fabric-covered furniture. The more these items come in contact with people, the more likely dust mites will be present.
Dust mites are most prolific in bedrooms where an average bed contains 10,000 dust mites and a 2-year-old pillow can get about one-tenth of its weight from dust mites, dead dust mites and their droppings. And carpeting may be home to millions more.
“While dust mites certainly make gross bedfellows, dust mites are harmless to most people. If you’re not allergic to the dust mite, you probably don’t even notice them. You can’t smell them, but dust mites do produce allergens that can trigger allergic uncomfortable reactions in approximately 80 percent of allergy sufferers,” he explained.
Koehler said dust mite protein and their fecal matter is the culprit. When this allergen becomes airborne and is inhaled, it can trigger asthma, hay fever or itchy skin reactions. A single dust mite can produce up to 20 microscopic pellets of fecal matter daily.
The typical life cycle of the dust mite ranges from 20 to 45 days, with some females laying as many as 80 eggs during this period. (The scientific names for the two most common American house dust mites are Dematophagoides farinae Hughes and Dermatophagoides pteronyssinus Trousessart.)
“Up close under an electron microscope, dust mites are very ugly little creatures and they’ve got sticky little feet that give them the ability to hold on, especially when you’re trying to vacuum them up.”
He said UF/IFAS research has shown dust mites thrive in warm, humid environments. Bedding usually provides these ideal conditions. Research also indicates dust mites will stop reproducing and die if the humidity level is 50 percent or lower. In Florida, humidity levels almost never go below 50 percent during summer months.
Marie Hammer, UF/IFAS home environment specialist, offered these suggestions for battling dust mites:
