Aphids are common pests that can attack a variety of home garden and landscape plants. Aphids are small, usually 1/8th inch or less, soft-bodied, pear shaped with long legs and antennae. Their color can vary from green, yellow, black, gray or red. They may have a pair of transparent wings. They are typically found clustering on young shoots and leaves and can occur on flowers, twigs, branches and roots.
Aphids in general will not kill a plant, but they can remove large quantities of sap, which will reduce the vigor of the plant, and cause stunted growth. Leaves may curl and turn yellow due to aphid feeding. Aphids can take in more plant sap than they can absorb and use. Excess sap is excreted as a clear, sweet, sticky substance called honeydew. Honeydew can be found on tree leaves and surfaces below trees that are infested. A black sooty mold may grow on the honeydew. Ants, flies, wasps and bees may be attracted to the sweet honeydew substance.
There are many natural predators that feed on aphids. They will help control the aphid population. A forceful stream of water can be used on durable plants to remove aphids. You can also prune off the infested growth and remove the aphids. Insecticide applications are sometimes needed if there are not enough predators and or other methods do not work. Several insecticides are labeled for aphid control. Contact your county Extension office, Master Gardener hotline or local nursery for more information.