How to Manage Pests

Seasonal development and life cycle—Pear rust mite

Female mites overwinter beneath bud scales and bark predominantly on 1- to 2-year-old wood. As buds open in spring, mites emerge, move to developing clusters, and feed within buds. As clusters open and leaves expand, some pear rust mites move to the leaf tissue and feed until leaves mature and harden, while large numbers remain on the fruit. As leaves mature, pear rust mites move either to young succulent leaf tissue or to fruit.

Eggs are produced shortly after adults become active in spring. Eggs are spherical and nearly clear when first laid. Immature mites grow rapidly through two instars.

Several generations occur each growing season; each takes only 10 to 14 days under ideal conditions. During the growing season, adults are pale white to cream colored. By late summer, only females are present, and they seek overwintering sites under scales of newly developed buds or in protected areas on 1- and 2-year-old twigs, unless tender new foliage is present, in which case they may remain active into November.