Apple-Apple rust mite

Aculus schlechtendali

Pest description and crop damage 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. Low populations should be tolerated, since rust mites are an alternate food source for predatory mites. However, they can cause russeting of Golden Delicious.

Biology and life history These mites overwinter as adult females under bud scales and in bark crevices. When growth begins they move out onto the leaves to feed, and produce several generations. In late July or early August they return to hibernate.

Management-biological control

Predator mites such as Typhlodromus spp. effectively control this mite.

Management-chemical control: HOME USE

Spring and summer

  • carbaryl-Highly toxic to bees.
  • kaolin clay-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests. Some formulations are OMRI-listed for organic use.
  • sulfur-Some formulations are OMRI-listed for organic use.

Management-chemical control: COMMERCIAL USE

Stages 5-6: Pink spray

  • fenbutatin-oxide (Vendex 50WP) at 1 to 2 lb/a in up to 100 gal water per application. Do not apply more than two times per growing season. Apply no more than 4 lb/a per growing season. PHI 14 days. [Group 12B]
  • fenpyroximate (FujiMite 5EC) at 2.0 pints/a in a minimum of 100 gal water per application. Only one application per season. Suppression only. PHI 14 days. [Group 21A]
  • kaolin clay-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests. Some formulations are OMRI-listed for organic use.
  • pyridaben (Nexter ) at 5.2 to 10.67 oz/a in up to 100 gal of water per application. Only one application per season. PHI 25 days. [Group 21A]
  • spirodiclofen (Envidor 2SC) at 16 to 18 oz/a in a minimum of 100 gal of water per application. Do not apply more than one application or 18 oz/a per growing season. PHI 7 days. [Group 23]
  • spirotetramat (Movento, Ultor) at 6 to 9 oz/a in up to 100 gal water per application. Do not exceed 25 fl oz/a per growing season. Do not apply after petal fall. PHI 7 days. [Group 23].

Spring and summer

Also, see control recommendations for pink stage bud development.

  • dicofol (Kelthane 50 WSP) at 1 to 4 lb/a in up to 100 gal of water per application. Do not use with glyodin fungicide, because phytotoxicity is possible. PHI 7 days.
  • fenbutatin-oxide (Vendex 50WP) at 1 to 2 lb/a in up to 100 gal water per application. Do not apply more than two times per growing season. Apply no more than 4 lb per acre per growing season. PHI 14 days. [Group 12B]
  • pyridaben (Nexter ) at 5.2 to 10.6 oz/a in up to 100 gal of water per application. Apply as populations begin to build, between petal fall and harvest. Ground application only. Do not exceed two applications per season. PHI 25 days. [Group 21A]
  • spirodiclofen (Envidor 2SC) at 16 to 18 oz/a in a minimum of 100 gal of water per application. Do not apply more than one application or 18 oz/a per growing season. PHI 7 days. [Group 23]