Every now and then I’ll get a call about tiny red spiders invading a home and invariably these turn out to be clover mites.
With its bright red to brown coloration it’s easy to see how this tiny parasite provokes so much alarm in the uninitiated.
‘When I squish it there’s a bloody spot, is it a bedbug?” “Does it bite?” “Will it infest my food?” “Can it damage my home?”
The answer to all the above is no. The only damage they cause comes from being squished. The red pigments in their bodies can stain some wall paints.
Clover mites, as their name implies, feed on the sap of clover, but will readily feed on grass and many other plants. They are not known for damaging plants, except cosmetically and then only when populations are extremely high.
Historically this mite has seldom been a pest of homes. The introduction of lawns, succulent landscape plants, and the use of fertilizer has helped make them much more common.
Adults typically lay eggs on tree bark and in other protected crevices including foundations and siding. Eggs laid in fall will overwinter and hatch in spring.
Eggs laid in late spring will remain dormant through the heat of summer to hatch into nymphs (immature mites) in fall. Nymphs will seek shelter to survive winter and may enter walls in large numbers. As spring arrives, more mites may be seen indoors as fall eggs hatch and nymphs and adults attempt to find their way out of buildings.
Once these mites get in the house the best thing to do is resist the urge to mash them with your finger. Second, resist spraying them with pesticides (inside your home). If they don’t get outside these mites usually die in a few days. The vacuum cleaner with brush attachment will usually dislodge them without mashing them into a spot on the wall.
Allowing grass to grow against the foundation helps support populations in close proximity to the building.
Densely planted flowers can do the same thing. Maintaining a one to three foot zone of rock along the foundation devoid of vegetation will reduce access to the building.
Maintaining your lawn in “golf course” condition with fertilizer and regular watering can spark a population boom. Be careful not to over fertilize.
As a last resort, a professional application of pesticide to a band of soil adjacent to the foundation and extending up the foundation can be used to suppress activity.
Large scale application to the yard is not recommended. ■