What are Clover Mites
By Chris Williams on June 20, 2011.
Q. My house is covered with thousands of these tiny red ‘bugs’. They’re even inside on the windowsills, walls, and on the floor too! What are they?
A. It sounds like it could be clover mites. While these ‘bugs’ are more closely related to ticks and spiders than they are to insects, the good news here is that they do not bite or transmit disease to humans or pets. The bad news is that they are soft-bodied and easily crushed which can cause staining on walls, woodwork, and fabrics. Plus, when they show up both indoors and outdoors in huge numbers, it can be a bit unnerving. Clover mites are tiny (smaller than the head of a common pin) red/reddish brown arachnids that are oval in shape. Like the spiders, clover mites have eight legs. Under magnification, they can be distinguished from other mite species by their extremely long front legs. They feed upon many different plant species including turf grasses, clover, dandelion, and iris. Female mites lay eggs in protected areas like within cracks of building foundations or underneath tree bark. These eggs may hatch in cooler fall weather or during the following spring.
Young clover mites molt several times before reaching the adult stage and this can occur in as little as one month’s time. Several generations of mites may be produced in a single season, but this is entirely dependent upon favorable weather. In general, clover mites are more active in cooler seasons like the spring and fall, and will congregate on the sunny sides of homes and commercial buildings. During the fall months as temperatures decrease, they will hide under siding, window frames, shingles or doorframes and may even migrate indoors. Occasionally throughout my career, I’ve seen them inside during the winter months in places like office buildings, but by far the biggest ‘explosions’ of clover mites I see where I live (NH) seem to be during April and May.
Although it is a good idea to remove turf and other vegetation from around the immediate perimeter of a building foundation (1 ½ to 2 feet) to discourage clover mites from living so close, it is by no means a guarantee against infestation. I’ve still seen them get into people’s homes (though not in huge numbers) where the owners have installed crushed stone, or other types of mulch. While these ‘cultural control’ methods are worthwhile, they should be augmented with some type of professional chemical control to help keep your environment a ‘mite free zone’.