If your otherwise healthy tree has recently begun to leak sap, you may have an aphid problem. Also referred to as greenfly, ant cow, or plant louse, there are approximately 4000 species of aphid worldwide. You can usually find these sap-sucking pests on plants and trees in low to moderate numbers. However, they sometimes congregate in large numbers, causing sap and dead leaves to rain down on the ground below.
Unfortunately, the sticky mess produced by aphids often lands on cars, decking and people who are trying to enjoy the shade.
Why Do They Make Such a Mess?
When there is a large population of aphids occupying a tree, it will seem as though the tree itself is leaking sap. In actual fact, most of what rains down isn't sap at all. Aphids suck sap from leaves, fresh buds and stems. Some excess sap may drip from the wounds they make, but the bulk of the liquid is actually the waste they produce, which is known as honeydew.
Honeydew is a clear, watery substance and is the reason that ants are often found farming and protecting aphid colonies.
Can Aphids Harm Trees?
In moderate numbers, the damage they do to trees is minimal. However, when conditions are right, such as when winters are mild and rainfall is scarce, aphid numbers may explode, and this is when trees can become stressed. Affected trees will experience stunted growth, loss of coloration, leaf loss and in extreme cases, even death. The worst thing about an aphid-infested tree, however, is usually the mess.
Aphid waste can permanently stain car paint and even make it difficult to open a car door should enough honeydew build up in one area.
How Can You Get Rid of Them?
Under normal circumstances, aphids' natural predators, such as lady birds and lacewings, help to keep aphid populations under control. Despite that, aphid numbers can sometimes balloon due to mild weather and a lack of natural predators in the area. When this happens, you will need to intervene.
To get their numbers under control you can use a combination of pruning and your garden hose to remove them. Remove heavily infested leaves and carefully blast off aphids with bursts of the garden hose.
If your tree is particularly large, you may need to call a tree service. A professional arborist will be able to examine the tree to determine the best course of action. They may either apply a soil insecticide or a spray as long as the tree isn't too large. Whatever method they use, you won't have to worry about aphid waste staining everything in sight any longer.
For information on how to care for your trees, contact a tree service in your area.