Rosy Apple Aphid (Aphids)
General Description
Hosts
Apple, pear, narrow-leaf plantain, and dock.
Damage
Leaves - Tightly curled on spur growth and at base of shoots (Fig. 1); usually much honeydew present within the curled leaf and on adjacent lower leaves. The aphids do not hide under a cottony wax-like covering and do not attack twigs or branches like woolly apple aphids.
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| Figure 1. Rosy apple aphid damage to apple leaves. (H. Philip) |
Branches - Young shoots twisted and deformed.
Fruit - Small and deformed near infested leaves; Jonagold fruit especially sensitive to aphid feeding (dimpled fruit surface with green spots throughout flesh) (Fig. 2).
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| Figure 2. Jonagold apples damaged by rosy apple aphid feeding. (BCMA) |
Identification
Egg - Dark greenish to shiny black, oval.
Nymph and adult - Pink to purplish, up to 2 mm long, coated with a very fine white powder-like covering. Some adults have wings (Fig. 3).
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| Figure 3. Rosy apple aphid colony. (BCMA) |
Life History
Rosy apple aphid overwinters as eggs on 2-year-old or older wood. Eggs hatch when buds open in the spring. After several generations, winged adults migrate to plantain for the summer. Winged adults return to apple in the fall where they lay overwintering eggs.
Monitoring
Carefully examine 10 leaves or bud clusters per tree on 10 standard trees per block or 5 clusters per tree on 20 dwarf trees per block, beginning at tight cluster or early pink stage.
Management
Biological Control
Rosy apple aphids are attacked by several insect predators and parasites that can aid in control of this pest if not harmed by toxic chemicals.
Chemical Control
See chemical control of apple aphid. Control may be necessary if aphids are present on 10 of 100 bud or fruit clusters in a 100-cluster sample and few predators are present. Summer sprays will also control other aphids.
Recommended control timing and products include: