There are nearly 8,000 unique species of scale insects, all varying greatly in appearance, but most are protected by their hard shell, or waxy covering. Mealybugs are a species of scale that are not armored and easier to deal with.
Scale insects are often found in groups or clusters and generally do not move much, if at all. The majority of scale insects do not have legs, and instead, remain in one place, sucking the sap out of the leaves of plants. They are small, bump like insects that can cause wilting of the leaves, yellowing discoloration, loss of foliage, stunted or no new growth, and honeydew, the sticky sap excreted from them. Black sooty mold will grow on the honeydew if it remains.
Scale insects can be difficult to deal with because they are generally armored, and reproduce asexually. Because of their protective covering, some contact insecticides are not effective. Horticultural oils have shown to work, which effective suffocate them in place. Additionally, systemic pesticides have been found to be effective, as they poison the sap in the plant, killing the scale insects as they feed.
They are disgusting, and detrimental to your plants, but they can be controlled with diligence.
You can either purchase and use a commercial solution that treats scale insects, such as Dead Bug Brew, or Insecticidal Soap solutions, (both found to be effective) or you can follow our At Home Recipe for a non-insecticidal alternative you can mix up and use.
Using a 16 ounce water spray bottle, combine 12 ounces of water, 4 ounces of 92% Isopropyl Rubbing Alcohol and 2 tablespoons of Dawn Dish Detergent. You can use other dish detergents, if you do not have Dawn, but we find that the classic, blue Dawn is the best.
If you can not find 92% Isopropyl Alcohol, you can use 70%, however you will want to alter your solution to 10 ounces of water and 6 ounces of Isopropyl Alcohol. Do your best to find the 92% though, as scale insects are tough to begin with and we find that they stronger isopropyl is much more effective.
With this solution in the spray bottle, thoroughly spray your entire plant. Be sure to cover both the top and undersides of the leaves, all stems and branches, and pay close attention to any new growth areas.
Because these pests can reproduce so quickly, you will have to spray your plant every 2-3 days for 2 weeks to ensure that all adults, larvae and eggs are killed and you stay ahead of them.
It is good practice to wipe the leaves of your plants clean after 2 or 3 treatments have been applied. This will remove any dead Mealybug adults, larvae and eggs. This can be done with a wet paper towel. There is no need to completely rinse your plant off after full treatment, simply wiping the dead scale off is good.
There is some risk in treating any plant with any insecticide or non-insecticidal treatment. You may notice some leaf browning, wilting or loss of leaves. This should correct itself relatively quickly, once the infestation is taken care of, and your plant is allowed to grow without hinderance.
If you have any further questions or need more assistance, please feel free to reach out to us.