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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Woolly Aphids -- Interesting but Messy

This article was published originally on 6/27/2012

The peculiar sight of "flying-fuzz balls" has been described before.  Several species of woolly aphids live on ornamental and fruit trees in the Iowa landscape.  When the winged adults take flight it appears that a small tuft of cotton has grown wings and is propelling around the lawn.  See the photo below.  Amazing.
 
Equally amazing in finding the colonies of aphids on the stems of the infested maple tree.  These feed on sap from the maple trees from the time of bud-break until late June. The immature nymphs are plump, purplish-gray, oblong and wingless. The nymphs will become covered with dense, white, waxy strands as they grow.
 
Winged adults, most with abdomens covered in white fluffy wax, are produced in the colonies. These winged migrants readily fly when disturbed.  Until they do, they create quite a sight.  The winged adults leave the maple trees and fly to alders where they will establish new colonies on the secondary host.
 
Control is not warranted though the aphids are easy enough to control with an application of insecticidal soap to small trees and lower branches.  The appearance of the woolly aphids may cause alarm but the aphids apparently cause no permanent damage. Some infested leaves may drop but this does not reduce the vigor of healthy trees.  Honeydew and sooty mold may be a problem on cars, plants and buildings underneath or adjacent to heavily infested trees.
 
 

 
Nymphs on a maple branch.
 

 
Adult aphids with wings on a branch.
 

Honeydew on a maple leaf from woolly aphids.
 
Woolly aphid - winged adult
 
Woolly aphid - winged adult