Aphids are soft-bodied insects that range from
1/16 to ? inch long. They may be green, yellowish, pink, gray or black. They
feed by piercing plant tissue and sucking plant sap. They prefer feeding on new
growth in such areas as shoots, buds and the undersides of leaves. As they feed
on plant sap, they excrete honeydew (a sugary material). The sooty mold fungus
feeds on the honeydew, resulting in unsightly, dark fungal growth.Woolly alder aphid (Paraprociphilus tessellatus) is gray to black in
color. It gets its name from the fluffy, white wax found on its abdomen. It
requires alder and silver maple to complete its life cycle. Occasionally, it is
found on red maple. Colonies of these pests are obvious because of their white,
fuzzy appearance. They are usually seen on leaves, twigs or bark. Although
infested leaves shrivel and drop early, the pests cause little permanent
damage. As a result of the honeydew, sidewalks and cars become sticky.
Several natural enemies, such as
ladybird beetles (ladybugs) and lacewings feed on aphids. As much as possible,
these predators should be allowed to reduce aphid populations. Controlling this
pest on a large tree using chemicals is expensive and often not practical.
Since little permanent damage results from woolly alder aphids, tolerating some
damage is a good choice. As a result of their phenomenal ability to reproduce,
aphids are very difficult to control with insecticides. Leaving one aphid alive
can result in the production of a new colony very quickly. In addition, the use
of insecticides kills the beneficial insects that normally keep aphid
populations under control.
However, if natural predators do not reduce aphid populations
sufficiently, the following foliar spray insecticides are recommended:
cyfluthrin, lambda cyhalothrin, permethrin, bifenthrin, pyrethrin and neem oil.
Treat when aphids appear and repeat at seven- to 10-day intervals, if needed.
As an alternative, dinotefuran or imidacloprid can be applied as a drench around
the root zone of aphid-infested plants and is systemically taken up by the root
system for insect control ..