Aphids, also known as Plant Lice,  make up an extremely large family of insects that feed on plants. Some species feed on foliage, some on twigs and branches, some on flowers and fruits and some even feed on plant roots. Aphids feed on just about any type of plant, both coniferous and deciduous. Most species are host specific and only feed on one or two different types of plants.

These soft bodied insects are relatively small in size, the largest are about 6 mm in length, but all can been seen by the naked eye. Aphids are oval to pear shaped and have two appendages coming out of the rear of their bodies called cornicles. Aphids typically overwinter as fertilized eggs, and hatch early in the growing season. They can be active year round in the greenhouse setting. All aphids without wings are females, and these females use parthenogenetic reproduction, which means they don’t need to mate to reproduce. This is why populations are known to explode literally overnight if the environmental conditions are right. They give birth to live babies. The males are the only ones with wings and they are responsible for moving the colonies from one host plant to the next. Aphids have a sucking mouthpart that looks like a long needle when seen under the microscope. They insert this mouthpart into the host plant and suck the liquids from the plant, which gives way to distorted growth by the host plant.

Use chemicals such as Marathon, Safari,  Flagship, Abamectin, Avid, Talstar, Sevin, Acephate and horticultural soaps and oils to treat. There are many native biological enemies of these pests such as green lacewings, lady beetles, and parasitic wasps.

By Matt Shultz, Horticultural Tech Support Specialist and Sales Representative, Harrell’s LLC and Marshall Horsman, Technical Services Manager, Harrell’s LLC.