Eriophyid Mites Pears and apples sometimes can be infested by various species of eriophyid mites. These minute mites cause several disorders on the leaves and fruit. For example, the pear russet mite causes a dark thickening of the pear fruit skin. Blister mites produce small, scabby patches on the leaf surfaces of both apple and pear. Eriophyid mites do not affect fruit production in backyard orchards, although the damage they produce sometimes attracts attention.
Horticultural oils sprayed during the dormant season can kill overwintering eggs.
Scale Insects Scale Insects occasionally damage apples and pears. Heavy infestations can cause death of infested branches and spotting of infested fruit and can contribute to a general decline of the tree. Scale infestations typically are slow to develop. Regular treatments are rarely needed in backyard orchards. Treatments with horticultural oils during dormant periods in spring can provide adequate control of these Insects.