You’re probably wondering what all this sticky mess is outside your house. It’s all over the patio and deck, and on the cars and driveway. It’s becoming a nuisance. You can’t sit on your furniture on a nice afternoon without getting it on your clothes and bringing it into the house. More than likely what you’ve got is an insect infestation very close to your residence that’s producing a substance called honeydew. It’s alarming but please don’t fret; it’s natural, nontoxic, and temporary.
Honeydew is excreted from sap-sucking insects or ‘phloem feeders’ such as aphids or soft scales. The spotted lantern fly is another culprit that is becoming a very prominent pest to our neighbors north of the Richmond area. As these various insects feast on the leaves of trees and plants, then drop this sugar-rich liquid that sticks to everything. The honeydew will collect over time and draw all kinds of other insects to come and consume it. Even fungus will take advantage of this opportunity in the form of sooty mold, which is the dark-colored coating on the honeydew.
Broadleaf trees such as tulip poplars and linden trees are prone to getting aphids ; whereas pecans, oaks, maples, and crape myrtles can get scale. The crape myrtles have been terribly infested with the CMBS or “crape myrtle bark scale” for the last 2 years. You may have also noticed the bark of the trees turning a dark color (due to the sooty mold). The honeydew will also get on the landscape beneath the trees, turning the leaves black so that the plants can no longer photosynthesize properly. This can cause long-term health effects and has been known to kill trees and plants.
Spring is the time when the sap is flowing in trees and plants, which brings all the bugs to the yard. The Aphids will come in droves, and their populations will flourish in the early to mid-summer after the spring showers cease to wash them away. But do not worry, because predators such as the wasp and ladybug larvae will show up soon after to eat the aphids and cut the infestation levels back down. Mother Nature is truly our greatest ally.
The CMBS can be treated with a soil drench, which is taken into the roots and kills the scale – but this process should be done by a professional. You can use dish detergent with a soft bristle brush to remove it from the bark and leaves. Use pesticides as a last resort, but the broadly-applied spray can kill the other beneficial insects in your garden and, as a result, have many unwanted side effects. Please consider Neem oil (keep this oil away from the bees) or White oil as a nature-friendly alternative.
Water is your best option. A spray can knock the bugs off of your trees and plants, and it can get the sooty mold off of everything by loosening the sticky bond. Then scrub with a brush or washcloth to remove the remaining residue. Don’t let the honeydew sit for long periods and harden, as it will become tough to remove. I would avoid using any harmful chemicals to clean, as the areas affected are generally close to trees and could get into the ground (and then get taken up by the root systems).
Whatever you choose, please remember to act responsibly in the meantime, and Mother Nature will deploy predators and rain to help in due time.