With a yard full of trees, you give your home an air of sturdiness and solidity. Yet no matter how solid your trees are, they’re vulnerable to insect attacks. Scale insects are a particularly serious pest in Southeast Michigan, attacking trees throughout the region and dealing serious damage. Thus as a homeowner, it is essential for you to know how to identify these pests and protect your plants from them. Only through a combination of preventative measures and insect elimination can you keep your trees safe and healthy for years to come.


Scale insects are a broad group of insects from the Hemiptera order. They are known for the waxy coating on their bodies, which gives them a shiny, scaly appearance. These waxy insects feed by piercing trees and other plants with their mouths and sucking out sap. They are most likely to operate in environments that are both warm and dry, making them a common source of trouble in Southeast Michigan during the summer.

A scale insect infestation can damage your trees over both the short and long terms. In the short run, these bugs will suck the sap out of the plants, making it harder for them to maintain the right amount of moisture and nutrients. Many scale bugs then excrete honeydew onto your trees, which is a major source of sustenance for sooty mold. Sooty mold outbreaks thus tend to follow in the wake of scale insect infestations, causing further damage to your trees down the road. This makes it critical that you get scale insect infestations under control as early as possible. The longer you let them continue and spread, the more they will harm your plants.​


The first step in eliminating scale insects is to identify them when they attack. This means figuring out which trees have been infested. Start by looking for honeydew on the trees, as well as yellow and light green sections of leaves and clusters of white egg sacs. You can also place double sticky tape on the branches of your trees to catch scale bugs.

Once you have detected a scale insect infestation, you should begin eliminating the pests as quickly as possible. This typically requires applying an insecticide treatment to infected areas. If the bugs in question are Lecanium scales, you can spray this treatment directly on the tree. But if you’re dealing with cottony maple scales, insecticide sprays may be ineffective or even counterproductive, as they will kill ladybugs, wasps, and other insects the feast on the pests. Instead, you will likely need to inject the treatment into the soil or apply it to the trunk. While this is more expensive, it should keep your tree free of scales for years.


While there are roughly 8,000 scale insect species in the world, not all of them predominate in Southeast Michigan. The most common of these pests in our region include:

The Cottony Maple Scale – A pest known for and named after its tendency to attack maple trees, this species does not cause as much direct damage to trees as other types of scale insects. It does, however, spread an especially large amount of honeydew on your trees. Not only does that leave the plants vulnerable to sooty mold infestations, but it also makes them less pleasant, as honeydew is sticky and tends to fall on anyone standing underneath. Cottony Maple bugs are also harder to get rid of than other scale insects, in part because the same treatments used to exterminate them will also kill their natural predators.

The Lecanium Scale – This bug attacks a wide variety of deciduous trees, with a particular preference for sugar maples, oaks, and ash trees. The insect excretes a similar amount of honeydew compared to its Cottony Maple cousin while causing substantially more damage to the structures of trees themselves. But it is also easier to control, as its natural predators are less likely to be harmed by the insecticides you use to kill it. Thus while it’s even more important to stop this species as early as possible, you won’t have as much time doing so.

Whether you’re dealing with Cottony Maple bugs, Lecanium pests, or any other variety of scale insect, the key to controlling them successfully is awareness. As a homeowner in Southeast Michigan, you must make sure to understand.

If you notice scale eggs on your trees but few adult bugs, you may be able to stop the infection early by killing the young pests. You can do this by applying a spray insecticide to the lower side of each leaf during late June and early July, just before these insects tend to hatch. While covering all the eggs in this way is difficult, if you can manage it, it is a highly effective way of eliminating these pests.

Don’t let scale insects destroy your trees! Contact a professional arborist today for quick, effective treatment and prevention services.