You recognize most of the insects that live in your yard. You know ants’ appearance and behavior. You can identify grasshoppers, beetles, and maybe even termites. But recently, a new insect invader has nested in your trees, and you have no idea what to call these pests or what to do about them. They don’t look like anything you’ve seen before, and they’ve made your trees sick.
Read below to see if this insect invader is scale. “Scale” may make you think of a tree disease rather than a pest, but this stubborn insect may prove more damaging than a disease if you don’t know how to control it.
What Do Scale Insects Look Like?
You could have one of over 1,000 species of scale insects in your backyard, but they all share features in common. Common characteristics of these insects include:
- Hard, almost inanimate shells that appear as bumps on your trees’ trunks and limbs
or soft shells that accompany a wax-like film and a sugary liquid called honeydew - A brown color that varies from dark to light
- Clusters of scale insects on parts of the plant, because they will not sit alone in most cases
Scale insects with hard shells cannot move. Some with soft shells do. But most of the time, once scale insects reach adulthood, they do not move from the place where they feed on the plant.
Other signs of a scale infestation include:
- Poor or stunted plant growth
- Yellow leaves and discolored stems
- Drooping leaves, twigs, and even limbs
- Trails of wax and honeydew on the plant
- Black fungus or sooty mold growing in the leftover honeydew
- Trails of ants that eat the honeydew
- Eggs covered in waxy white fibers, usually on leaves’ undersides
Scale insects don’t grow large, but their shells will gradually become larger with time. You may also see their immature nymphs running about the plant. The nymphs do not have wings or any other obvious body parts. They look like minuscule, pill-shaped blobs, and they can only move at this stage in their life cycle.
What Do Scale Insects Do?
When nymphs emerge from their eggs, they move a little ways away from the colony to find unoccupied plant matter and sink their teeth into it. And once they bite down, they continue to eat and drink from the plant in that location until their shells grow over them. At that point, as previously mentioned, scale insects with hard shells won’t move again. Those with soft shells may slowly progress along the tree.
Since scale insects steal nutrients that your plant would otherwise use to grow, your plants won’t become as lush and verdant as they would without a scale infestation. The insects may even kill your trees if you have a big enough infestation. Your trees could also contract an infection if bacteria or fungi enter through the bites.
What Can You Do to Eradicate Scale Insects?
You have a few options if you notice scale attacking your trees. Your solutions include the following:
- Remove and destroy branches, twigs, and leaves that the insects have infested.
- Pick the insects off by hand with small infestations. Just remember to spray bug repellent afterward.
- Coat individual insects with pest repellent or even rubbing alcohol. Make sure you inundate each scale with chemicals, but not so much that the chemicals could harm the tree.
- Set loose beneficial insects like ladybugs, lacewings, wasps, and praying mantises. You can buy these insects at your gardening store, and they’ll eat the eggs and nymphs for you.
- Install tape traps around infested areas to capture and kill nymphs. You can even use double-sided tape as a simple trap as long as you replace it often.
Keep in mind that scale insects’ shells protect them from many pesticides and other chemicals that would kill other pests. So make sure you choose chemicals that contain rapeseed oil, pyrethrum, thiacloprid, or tar oil wash. Use cotton swabs to dab the chemicals directly onto the scale insects as well. You don’t want the pesticides to seep into the soil and weaken your already suffering trees.
What If Home Treatments Don’t Work?
If the treatments listed above don’t work, then you still have a solution. You can call a professional. Professional arborists or exterminators have access to more powerful and more focused treatments that will eradicate a scale infestation in no time. Consider skipping the home treatments and call an expert immediately if scale attacks large, old, or sentimentally important trees.
Once the arborist has helped you with the infestation, he or she can nourish your trees and other plants so they recover. A healthy plant can defend better against future infestations than a sickly plant.
If different organism has attacked your trees, or if you simply want to learn more about keeping your trees healthy, have a look at our other blog posts.
The post What Is Scale, and How Can You Prevent It? appeared first on Schulhoff Tree and Lawn Care.