Description
Aphids that cover themselves with white or gray waxy threads that look like wool or cotton are called woolly aphids. If the threads are removed, small (1/8 inch), dark, soft-bodied insects will be found clustered beneath. Woolly aphids infest only woody plants. Some species infest leaves, often causing them to curl inward. The damage is unsightly but rarely fatal to the plant. Other types of woolly aphids cover the trunk, branches, and roots. Galls may develop where they feed, and infested roots may be heavily branched. Young plants severely infested with woolly aphids are often stunted and may die. Older plants with galls on the roots may be weak and produce less fruit. Most of these aphids have a summer and a winter host. They spend the summer on 1 type of plant and then, in the fall, produce a generation that migrates to another plant species. Sometimes, especially in warmer climates, woolly aphids spend the entire year on the summer host.
Control
Woolly aphids protected inside curled leaves are best controlled with a systemic insecticide such as an insecticide containing acephate. Use acephate or an insecticide containing malathion on woolly aphids infesting branches or trunks. Make sure your plant is listed on the product label. Repeat the spray if the plant becomes reinfested.
