Woolly aphid adults are pear shaped, usually 0.13 inch or less in length, and cover themselves with white
Identification of species
Some species feed in groups and cause swellings on bark or roots. Cankers and burs or burls can develop
on limbs. On roots, nodular masses of gall tissue may form. Foliage-feeding species can cause infested
leaves to curl, distort, discolor, or form into galls. Some species secrete honeydew, which results in
growth of blackish sooty mold. Others produce pale waxy secretions, causing white flocculent material
to collect on and beneath infested plants. Gall-making species may confine their honeydew or wax to within
distorted tissue so this secretion is not obvious unless galls are cut open.
enemies and the parasite Aphelinus mali help
to control aphids, but may not appear in sufficient numbers
until aphids are abundant. If aphids cannot be tolerated
and insecticides are deemed necessary,
use materials such as insecticidal
soaps and narrow-range
oils. Oil and soap professionally applied with
a high-pressure sprayer can provide some control. Homeowner
application of these materials isn't highly effective. Spot
treat where aphids are most abundant to preserve natural
enemies elsewhere. Repeated soap
sprays may wash away stickiness and exposed cast skins. Manage
ants as they can disrupt biological control.
Where aphids feed within curled leaves acephate can
be used on ornamentals, but is toxic to natural enemies.
Other controls have not been investigated.
Woolly apple aphid adults
Burs on limbs caused by woolly apple aphids