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How to identify it
- Size figures vary: Penn State says adults are 0.75 mm long, Clemson about 1/30 inch, and the Pacific Northwest handbook about 1/16 inch. Colors are given as reddish-brown, rusty red, or greenish to olive green.[2][5][6][1]
- The first pair of legs is very long, about twice as long as the others, and held out in front so it looks like antennae.[2][5][7]
- To the naked eye they look like moving dark specks; Colorado State says they are often described as walking dust specks.[1][7]
- Crushed mites leave a red-brown stain from their body pigments, not blood, and Clemson says it can be hard to remove from fabrics and walls.[1][5][7]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Banks grass mite | Another turf mite, but smaller, usually green and paler, and without the clover mite's long front legs.[7] |
Where it lives
Feed on clover and grasses, especially lush, well-fertilized lawns; they overwinter as eggs in cracks in concrete, under bark and in walls, and are often seen on sunny windowsills.[1][2]
Biology and life cycle
They feed on clover, grasses and more than 200 other landscape plants, and do especially well in lush, well-fertilized lawns.[1][5][4]
Only females are known; they reproduce without mating. Studies have linked this to Wolbachia bacteria: antibiotic treatment showed the infection is strictly tied to the mites' all-female reproduction.[2][5][9][8]
They overwinter mainly as eggs in cracks in concrete, under tree bark and in building walls. Penn State says eggs hatch in early spring, around April 1 or once temperatures pass 45°F, and egg to adult takes about a month.[2][5]
They are cool-season mites that go dormant in summer. Penn State describes one spring and one fall generation; Colorado State says two or more outdoor generations develop during the cool seasons.[2][7][5]
In laboratory tests, development sped up as temperature rose to 32.5°C (about 90°F); at 35°C (95°F) females laid eggs but none hatched, and egg laying peaked at 20°C (68°F).[8]
They gather on the sunny side of buildings, and Colorado State says they almost always enter on the sun-exposed south and west sides. Penn State notes they became more common as household pests after World War II, possibly linked to more lawn fertilizer use.[4][7][2]
Damage and signs
- Indoors they are mainly a nuisance of large numbers and stains when crushed; they don't infest household products or feed on furnishings.[1][7]
- In lawns, heavy feeding can give grass a bronze or silvery look. Colorado State says injury shows as small silver streaks, nearly always within about 10 feet of a building or tree, and is often mistaken for winter kill.[5][7]
Health risk
Clover mites don't bite or feed on blood and won't harm people or pets.[1][2][7]
Control
Prevention
Keep grass and other host plants away from the foundation. Recommended widths differ: Penn State says a grass-free band 6 to 24 inches wide, Clemson about 18 inches, and Colorado State about 3 feet, which mites sometimes still cross. Clemson suggests filling the strip with pea gravel or plants mites avoid, while Minnesota says landscape rock alone isn't enough and plants in the strip should be spaced so mites can't bridge it.[2][5][7][4][1]
Avoid overfertilizing the lawn, which lets mite numbers build up. Colorado State adds that extra watering of warm, dry spots at the base of sunny walls reduces lawn populations.[1][7]
Spring invasions end on their own when warm weather sends the mites into summer dormancy, usually by late May or early June.[7]
Keep them out
Caulk cracks around windows and other entry points. Colorado State says a fine layer of dust such as talc, diatomaceous earth, baking soda or corn starch around windows can stop them crossing.[5][7]
Traps and physical control
Wipe mites up with a damp sponge or soapy rag, or use a vacuum crevice tool, taking care not to crush them. Clemson suggests putting the vacuum bag in an outside trash can. Don't apply insecticides to indoor surfaces.[1][5][2]
Pesticides
Mites on outside walls can be killed with a direct spray of insecticidal soap or 2 tablespoons of dish soap per gallon of water, though it leaves no residual control. Sources differ on perimeter treatments: Penn State and Minnesota describe exterior and lawn treatments near the foundation, while Colorado State says no chemical control is highly effective and the Pacific Northwest handbook keeps professional perimeter sprays for extreme cases.[1][2][4][7][6]
Common questions
- Are the red stains blood?
- No. The stains come from the mites' body pigments; clover mites don't feed on blood.[1][7]
- Will clover mites breed in my house?
- No. They don't reproduce indoors and die on their own soon after they get inside.[2][1]
- Why is the grass along my foundation silvery or dead in spring?
- It may be clover mite feeding. Colorado State says the damage is concentrated in sunny, dry areas within about 10 feet of a building and is often mistaken for winter kill.[7][5]
Sources
- University of Kentucky Entomology, “ENTFACT-627: Clover Mites.” entomology.mgcafe.uky.edu/ef627 (accessed 2026-11-11)
- Penn State Extension, “Clover Mites.” extension.psu.edu/clover-mites (accessed 2026-11-11)
- iNaturalist, “Bryobia praetiosa taxon page (order and family).” www.inaturalist.org/taxa/263127 (accessed 2026-11-11)
- University of Minnesota Extension, “Clover mites.” extension.umn.edu/insect-relatives/clover-mites (accessed 2026-11-11)
- Clemson Cooperative Extension Home & Garden Information Center, “Clover Mites.” hgic.clemson.edu/factsheet/clover-mites/ (accessed 2026-11-11)
- Pacific Northwest Pest Management Handbooks, “Nuisance and household pests: Clover mite.” pnwhandbooks.org/insect/structural-health/nuisance-household/nuisance-household-clover-mite (accessed 2026-11-11)
- Colorado State University Extension, “Clover Mites and Other Mites of Turfgrass, Fact Sheet 5.505.” extension.colostate.edu/topic-areas/insects/clover-and-other-mites-of-turfgrass-5-505/ (accessed 2026-11-11)
- Journal of Economic Entomology, via PubMed, “Ullah MS, Kamimura T, Gotoh T (2020), Effects of temperature on demographic parameters of Bryobia praetiosa (Acari: Tetranychidae), Journal of Economic Entomology 113(1):211-221.” pubmed.ncbi.nlm.nih.gov/31785205/ (accessed 2026-11-11). Cited from the PubMed abstract.
- Proceedings of the Royal Society B, via PubMed, “Weeks AR, Breeuwer JA (2001), Wolbachia-induced parthenogenesis in a genus of phytophagous mites, Proceedings of the Royal Society B 268(1482):2245-2251.” pubmed.ncbi.nlm.nih.gov/11674872/ (accessed 2026-11-11). Cited from the PubMed abstract.