Clover Mites

Facts, Identification & Control

SCIENTIFIC NAME

Bryobia praetiosa

APPEARANCE

Clover mite adults are oval shaped, eight legged, red colored and about as small as the head of a pin. The front pair of legs is very long compared to the other six legs and may be confused for the mite’s antennae.

BEHAVIOR, DIET & HABIT

Mite Picture
Illustration of a Mite

Although clover mites are not a danger to human health and do not destroy furniture, clothing or food items, they can become an indoor nuisance when invading homes, business and medical facilities. Once inside, they will soon die, but not until they have created problems resulting from an annoying presence and cosmetic damage from red stains resulting from mites that are crushed. This stain is not the mite’s blood, but is the mite’s body pigments. Clover mites are not blood feeders, but feed on plants getting their nutrition from sucking plant juices from grasses, clover and other plants common to lawns. Clover mites can become a nuisance in multi-story buildings since they can live on rooftops and patios where mold or mildew provide sources of food.

Clover mites go through 4 life stages – eggs, larvae, nymphs and adults. The clover mite overwinters in any dry protected location primarily in the egg stage. Sidewalk cracks, walls of buildings and logs can host vast numbers of overwintering eggs.

The overwintering eggs hatch early in the spring and clover mite adults become active as soon as the temperature warm above about the mid-forties and begin to climb up the exterior walls from the ground and gain entrance around windows and doors. Overwintering mites hatch in the spring and begin to produce second generations. Spring generations will aestivate, which is a form of summer hibernation where mites go inactive on warm, dry days. Second generations typically complete in the fall.

REPRODUCTION

Clover mite populations may become large since females can lay up to 70 eggs and each becomes a mature adult in 30 days or less under suitable circumstances. Clover mites reproduce by parthenogenesis, which means the females are able to reproduce without being fertilized by the males.

SIGNS OF AN INFESTATION

Observance of the reddish colored clover mites crawling on surfaces such as windowsills and siding on the sunny sides of homes are the most obvious indicator of an infestation.

DISTRIBUTION

Clover mites are found throughout the United States.

MORE INFORMATION

Control of clover mites is best left to your pest management professional (PMP). Your PMP will perform an inspection and use the inspection findings to prepare an integrated pest management plan for clover mite control. Your PMP will use his expertise and knowledge to recommend the application of effective and efficient chemical control measures to reduce the clover mite problem. However, his control program will likely include some helpful preventive measures the homeowner may choose to employ, as well. Among these preventive measures are:

  • Using a wet sponge or a crevice attachment of a vacuum cleaner to remove mites, making sure to take precautions to avoid crushing the mites and causing stains.
  • Removing all grass and weeds from around the foundation perimeter and leaving vegetation free strip about two feet wide. This method is especially important on the south and southwest sides of the structure. Clover mites are not as likely to move through bare, loose soil as they are through soil that is supporting plants that touch the structure’s foundation. Use of pea gravel can also discourage mite movement into the structure.
  • Sealing holes, cracks and gaps on the foundations, windows and doors, thus helping discourage mites from entering the structure.
  • Making sure to use window screens that are tight fitting.
  • Making sure not to over-fertilize the lawn or ornamental plant areas since clover mite populations tend to do better in lawns that are well fertilized.