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How to identify it
- Adults are tiny, about 1/60 inch (0.02 inch) long, oval, and yellowish green to yellowish brown, turning brown with age, with two red eyes. Males are slightly smaller than females, with a pointed hind end.[2][3][1]
- The McDaniel mite carries several dark spots on its back; the PNW handbook counts four, where the twospotted spider mite has two.[3][2][1]
- Overwintering females are orange and unspotted, and turn green once they start feeding in spring. Eggs are round and translucent to opaque or yellowish; the young look like small, paler adults.[2][3][1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Twospotted spider mite | Utah State and the PNW handbook cover it alongside the McDaniel mite, with the same kind of leaf damage; it has just two dark spots on its back.[3][2] |
| European red mite | Adults are globular and red with white spines, and it overwinters as red, globular eggs in bark crevices on twigs and young limbs instead of as adult females.[3] |
Where it lives
Utah State covers it in Utah orchards and landscapes, and the Pacific Northwest handbooks list it among the spider mites of the region's tree fruit.[2][1][3]
Biology and life cycle
It is typically found on fruit trees but has many hosts. Utah State's fruit page lists apple, apricot, cherry, peach and nectarine, pear, and cane and bramble berries as hosts of it and the twospotted spider mite.[1][2]
Mated females spend the winter under bark or in soil debris around the host plants. In spring, once active, they move onto the young foliage and begin laying eggs.[3][1]
Spider mites on fruit trees breed fast in hot, dry weather. A female can lay up to 10 eggs a day and more than 200 in her life, an egg can become an adult in 7 to 10 days in summer, and the overlapping generations continue from spring to autumn.[3][1]
Mites spread on the wind, and large colonies spin fine webbing along the leaf midribs.[1][3]
Damage and signs
- Mites puncture leaf cells and suck out the contents, leaving small yellow-white stipples on the upper leaf surface. In heavy infestations the spots run together and the leaves yellow or bronze, then brown, dry and drop early, and the webbing gives the tree a dirty look.[3][1][2]
- On fruit trees, heavy feeding reduces tree vigor and fruit color, size and yield. Utah State also lists russeting on pear fruit and scarred, shriveled tart cherries, and notes that mite-stressed trees are more prone to winter injury and death.[2]
Health risk
It is a plant-feeding mite; Utah State and the PNW handbook describe only damage to plants and mention no risk to people or pets.[1][3]
Control
Prevention
Avoid dry, dusty conditions and plant stress. Water trees properly, since drought-stressed trees are more susceptible; avoid excess nitrogen; and use cover crops to cut dust. Broadleaf weeds such as mallow, bindweed, white clover and knotweed build up mite numbers, so keep them down.[3][1]
Traps and physical control
Check for mites from April with a paper test: hold a sheet of white paper under a branch, shake the branch hard, and watch for tiny moving specks. Home growers can knock mites back by spraying the tops and undersides of the leaves with a strong stream of water.[1][3]
Biological control
Natural enemies usually bring spider mites under control by midsummer if broad-spectrum insecticides are avoided. In Utah orchards the western predatory mite, Typhlodromus occidentalis, gives the most consistent control; Stethorus lady beetles, minute pirate bugs and other predatory bugs, some thrips and lacewings also feed on spider mites, and predatory mites can be bought to boost their numbers.[3][2]
Pesticides
Spray only when needed. Utah State warns that miticides often make mite problems worse by killing predatory mites, and that twospotted and McDaniel mite populations have developed resistance to miticides; the PNW handbook advises avoiding pyrethroid sprays during the growing season. Home-use options it lists include horticultural mineral oil, insecticidal soap (not during bloom, with thorough coverage of leaf undersides), azadirachtin (neem) and sulfur.[2][3]
Common questions
- How do I tell McDaniel spider mites from twospotted spider mites?
- Look at the backs of the adults: twospotted adults have two dark spots, while McDaniel adults have more, four according to the PNW handbook. Both are tiny, about 1/60 inch long.[3][2]
- Why did spider mites get worse after I sprayed my fruit trees?
- Broad-spectrum sprays and many miticides kill the predatory mites that normally hold spider mites below damaging levels, and McDaniel and twospotted mites have developed resistance to miticides, so spraying often makes the problem worse.[2][3]
- When should I start looking for them?
- Start in April with the paper test, and keep checking leaf undersides along the midrib through hot, dry weather; stippled or yellowing leaves are often easier to spot than the mites themselves.[1][3]
Sources
- Utah State University Extension, Integrated Pest Management, “Two-Spotted and McDaniel Spider Mites (Ornamental Pest Guide).” extension.usu.edu/planthealth/ipm/ornamental-pest-guide/arthopods/mites/two-spotted-mcdaniel-spider-mites.php (accessed 2026-11-08)
- Utah State University Extension, Integrated Pest Management, “Spider Mites on Fruit.” extension.usu.edu/planthealth/ipm/notes_ag/fruit-spider-mites.php (accessed 2026-11-08)
- Pacific Northwest Pest Management Handbooks (Oregon State, Washington State and University of Idaho Extension), “Peach and nectarine-Spider mite (Pacific Northwest Insect Management Handbook).” pnwhandbooks.org/insect/tree-fruit/peach-nectarine/peach-nectarine-spider-mite (accessed 2026-11-08)
- iNaturalist, “Tetranychus mcdanieli taxon page (order and family).” www.inaturalist.org/taxa/1475386 (accessed 2026-11-08)