Apple rust mite
Aculus schlechtendali
1 host plant
Last updated
Apple rust mites are too small to see without magnification, but their feeding produces a characteristic bronze or russeted discoloration on apple leaves and fruit skin. You will notice the damage first as a subtle dulling of leaf surfaces in early summer, progressing to a leathery brown texture by midsummer. These eriophyid mites overwinter under bud scales and emerge with new growth.
Predatory mites, particularly Typhlodromus species, provide excellent biological control when conserved. Avoid carbaryl and other broad-spectrum insecticides that destroy these natural enemies. Dormant oil in late winter reduces overwintering populations. Sulfur sprays during the growing season offer targeted control if predator populations are insufficient.
Quick Reference
Extremely small, wedge-shaped mite, which is tan to amber colored. Magnification is required to see this mite. Feeding makes leaves look off-color, sometimes with a silvery sheen. Leaves roll lengthwise. Feeding shuts down terminal growth. Populations of apple rust mite should be tolerated because rust mites are an important alternate food source for predatory mites. However, rust mite can cause russeting on 'Golden Delicious' or other green/fair colored apples and some control may be required...