Hosts: apple, pear
Biology: Rust mites are microscopic mites in the eriophyid group. Adults overwinter under leaf bud scales of pear and apple, and emerge with new leaf growth in the spring.
Symptoms: Russeted fruit; pear leaves are sensitive to rust mites, becoming bronzed or scorched.
Monitoring: Use a hand lens to inspect leaves starting in mid-spring.
Treatment Threshold: No threshold determined.
Degree Day Model: None
Management Considerations: In apple, rust mites can be beneficial in that they may serve as alternative prey for predatory mites that also help suppress spider mites. In pear, lower populations can be tolerated.