Aphids are very common. Sometimes called plant lice, they are small, soft-bodied, pear-shaped insects, generally less than 1/8" long. Most are green or black but they can also be found in a variety of other colors as well. A characteristic common to all aphids is the presence of cornicles, or tubes, on the back ends of their bodies, sort of like "tailpipes". These cornicles secrete substances that help protect the aphids from predators.

Aphids are small insects which thrive on just about any plant. Any gardener or farmer knows what aphids are and may consider them their number one enemy. Also known as plant lice, these small but persistent insects seem to appear out of thin air and will encompass all the new green growth of any plant they can find.

Aphids have piercing chewing mouthparts which enable them to feed off the sap or life blood of any plant. They are much like Fleas or Mosquitoes are to mammals; Aphids seek the blood of plant life and won't stop feeding regardless of how much they hurt or stunt the plant. They transmit some lovely, fresh-picked viruses directly into your leaves, flowers, and stems. To make matters worse, they even have the audacity to leave sweet, sticky anal secretions called honeydew all over your leaves, where, unless it's eaten by ants, quickly turns grayish black with mold and blocks the sun. Now imagine watching your leaves as they curl up, yellow, die, and drop into oblivion.

Aphids feed in clusters, or large groups, and usually prefer new, succulent shoots or young leaves. Some species, known as woolly aphids, are covered with white, waxy filaments which they produce from special glands. You will usually find aphids clustered on leaves, needles, stems, and at the base of blossoms.

Damage symptoms caused by aphids include foliage that is distorted, crinkled, rolled, yellowed, swollen, or stunted. For larger trees, if you feel it is necessary to manage aphids because of excessive "honeydew" production, or if they are a gall-forming species, the systemic insecticides can be applied. .

Protection of naturally occurring beneficial insects, such as lady beetles (ladybugs) and green lacewings is very important in keeping aphid populations under control, but the purchase and release of these beneficial insects is often not effective because they do not remain in the area after they are released.

Ants often protect aphids from their natural enemies, and in turn, eat the honeydew produced by the aphids. This allows aphid populations to expand rapidly. If you find ants on ornamentals in your yard, this is probably why they are there. Aphids attack both deciduous and evergreen trees, as well as your bedding plants. For example Spruce Gall is caused by the larval stage of the aphid. On deciduous trees and bedding plants look for the honeydew, presence of ants, and on the evergreens the new growth will have brown tip die back.

Aphids have unusual and complex life cycles which allow them to build up tremendous populations in very short periods of time. Most aphids overwinter, or spend the winter, as fertilized eggs glued to stems or other parts of plants. Nymphs which hatch from these eggs become wingless females known as stem mothers. There are no males present at this time. Stem mothers reproduce without mating, and their eggs are held within their bodies until they hatch so that young are born alive. All offspring are females which soon mature and begin to reproduce in the same way. This pattern continues for as long as conditions are favorable.

Periodically, some or all of the young develop wings and migrate to other plants. Some species always settle on the same type of plant; others have one or more alternate hosts. When the days get shorter in the fall and there are cooler temperatures, a generation appears which includes both males and females. After mating, these females lay the fertilized eggs which overwinter and eventually hatch into stem mothers the following spring. In summary there are biological, cultural and chemical controls.