-- These aphids infest the undersides of leaves, leaf stalks, and tender
twigs of trees in the red and white oak groups throughout the East.
Heavy infestations distort the foliage and weaken the plants. Honeydew
and sooty molds further mar the beauty of ornamentals.
Insect (figure 36). -- The aphids are .04 to .06 inch (1 to 1.5
mm) long, soft-bodied, pearshaped, with a pair of cornicles at posterior
of abdomen. They may be yellow, green, pink, or brown, with darker pigmented
blotches on the abdomen, and dusky bands on wings. Winged and wingless
Injury. -- Clusters of aphids feed largely on the underside of the
leaves. Feeding injury curls and folds the leaves. Every leaf on a tree
may be curled and distorted during heavy attacks. Leaf surfaces become
sticky with honeydew followed by growth of black, sooty fungus.
-- Overwintering occurs as eggs deposited in bark crevices of host plants.
The eggs hatch in the spring and nymphs begin feeding on the leaves.
There are several generations per year, but the highest populations
have been observed during the spring.
-- Natural enemies usually keep infestations in check. Insecticides
are sometimes needed on ornamentals and other high-value trees.