How to Manage Pests

Pests in Gardens and Landscapes

Pearleaf blister mite—Phytoptus pyri

Adult mites are very small and cannot be seen without a 14 to 20X hand lens. The body is white, long and slender, striated, and with a few long hairs. Immature forms resemble adults but are smaller.

Identification of species | Life cycle


Mites feed under the bud scales during winter and may cause buds to dry and fail to develop in spring. Feeding on pears results in oval russet spots, usually depressed with a surrounding halo of clear tissue. Mature fruit is often deformed and misshapen. Leaf feeding causes small blisters that are first red and later blacken.


In backyard situations, natural enemies usually keep bud mites under fairly good control. For high populations, apply a horticultural oil spray after harvest during late October or November. Once fruit is set, damage has already occurred and cannot be corrected.

Adult pearleaf blister mites
Adult pearleaf blister mites
Blisters on leaves
Blisters leaves
Russet spots on fruit
Russet spots on fruit

Statewide IPM Program, Agriculture and Natural Resources, University of California
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