If you have these clumpy-looking patches on your leaves and plants, there’s a good chance you’ve got unwanted scale insects on your vegetation. These little sapsuckers range from ⅛ inch to ½ inch in size – and although they are tiny in stature – they can cause big problems for your plants.
Scale insects may be on your plants because they are feeding, staying close together to other scale, and can be looking for protection. If you notice scale insects on your plants you can manually remove them with a toothbrush dipped in dish-soap or use neem oil to get rid of them.
Scale insects can be a challenge, and we recommend that if you have a large infestation to contact a professional right away – they will be able to create a plan to get rid of the scale insects effectively and completely. However, there are still some things you can do to get rid of scale insects – and we’re going to talk about that today!
What Are Scale Insects?
First things first, what are scale insects anyways? Scale insects are these teeny-tiny critters, that are covered in a wax-like coating that looks like armor, almost of which resembles a scale of a fish or reptile!
They have oval to round bodies and may be hard to determine because they look like spots on a leaf from far away.
According to the Wisconsin Division of Education, female scale insects do not have antennae or legs and are immobile. Male scale insects are incapable of feeding as they don’t have mouthparts and are not commonly seen.
Scale insects most commonly attach to ornamental shrubs, shade trees, and fruit trees, and will suck the sap from the leaves to feed. Unfortunately, they can deteriorate entire trees and plants if they are found in large quantities.
Now to really get you going. according to this literature based review published in Oxford Academic, there are at least 8194 different species of scale insects. YIKES.
Why Are Scale Insects On My Plant?
Scale insects are on your plants for a number of reasons: they feast on your plant’s nutrients, they find protection on certain host plants, and they are simply on your plant because they congregate together. However, the way scale insects get onto your plants is a whole other story.
Scale insects offspring can crawl, walk, and find host plants. After this, the scale insects go through stages of molt, which is comparable to the changing stages of a butterfly, in which they lose their legs and antenna, and become immobile.
However, as adults, if scale insects get on to your plants it’s either because the pot you used was infected with them previously and had some scale insects left over or they could have been blown to your plants in the wind.
Let’s dive into the reason why they chose your host plant in the first place!
Scale Insects Feast On Your Plant’s Nutrients
Scale insects simply feast on your plant’s nutrients, and according to the Statewide Integrated Pest Management System, a scale insect can live its entire life in one spot.
The scale insects will have eggs in that spot, and then the baby scale insects will find a new host or the same host to feed – and that’s just how the cycle goes.
Scale insects will suck all the sap from your leaves and plants and will cause your plant to wilt and turn yellow.
Followed by feeding, scale insects excrete a sticky “honeydew” onto your plants that turn into Sooty Mold. Sooty Mold will turn your leaves black and destroy your plant.
Scale Insects Are Protected By The Foliage Of Your Plant
Believe it or not, scale insects do know what they’re doing when they choose a host plant, and a lot of the time, they choose plants with a lot of foliage because it will keep them protected from predators!
Scale insects have a lot of predators such as wasps, beetles, insects, lacewings, and mites, so if they attach to plants with a lot of foliage, not only will they have a lot to feast on – but, they will be hidden from predators.
And hey – although this can be an even bigger issue, if you’re noticing a lot of wasps in your garden, there’s a good chance you may have some scale insects on your plants! Check out our article about some things that may be attracting wasps to your yard, and what to do about it!
Scale Insects Congregate On Plants Together
Another reason why scale insects are on your plants in bulk is that they congregate together. As the University of Florida states, they can appear like fluffs of cotton on your plant.
These scale insects stay close-knit and in groups, appearing to be a connected clump on your plants! Plus, a female can lay eggs underneath its waxy, scaly, armor, right on the same host!
Okay but enough about why they’re on your plants – if you notice them, it’s time to get rid of the scale insects! So, keep on reading to find out more!
Unfortunately, this is one of the main reasons why scale insects spread to other plants.
9 Best Ways To Get Rid Of Scale Insects For Good
Getting rid of scale insects can range in complexity depending on how large the infestation is, whether they spread, the type of scale insect and etc. Moreover, whenever dealing with pests of any kind, we recommend contacting a professional as soon as you can!
If you’ve contacted a professional already or want to try some things on your own – here are the best ways to get rid of scale insects for good!
Manually Scrape The Scale Insects Off Your Plant
If you’re not too squeamish you can actually remove the scale insects manually – and especially if you only notice a small amount, this may be the best thing to do!
By taking a toothbrush or cotton swab, and while wearing gloves, you can gently wipe the scale insects off of your plants.
For extra help, dipping the toothbrush or cotton swab in dish soap will help glide the scale insects off the plant!
Manually scraping the scale insects off your plant can be the easiest, quickest, and most effective way to get rid of the scale insects before they take over your plants.
Isolate Your Plant If Possible
Another way to stop the spread of scale insects is to take the infected plant and isolate it from all other plants, if possible. This may mean digging the plant out of the garden or moving the pot away from other vegetation.
Of course, you may not be able to isolate a tree as easily as you would a plant or shrub, but, if you find that scale insects have attached to at least one plant – removing and isolating the plant as quickly as possible is the best thing you can do.
Once the scale insects spread – it’s hard to manage. Plus, they can easily deteriorate entire plants if the infestation gets out of hand.
Neem Oil Is Amazing Against Scale Insects
Another effective method in getting rid of scale insects is to use neem oil as an insecticide against them.
According to the Environmental Protection Agency, Neem Oil is made by cold pressing the seeds of the Neem Tree and is proven to be an effective insecticide, so much so that it is used commonly as the active ingredient in many insecticides for purchase.
You can easily purchase Neem Oil, like this Organic Neem Cold Press Oil from Amazon. To use Neem Oil, you can directly add the oil with a cotton swab to the problem areas.
For larger scale scale insects (see what I did there), you can create a Neem Oil spray solution: mix a few drops of neem oil into a spray bottle filled with water, and use that solution to spray directly onto the scale.
Bonide Captain Jack’s Neem Oil Insecticide is another great insecticide that uses Neem Oil as its active ingredient. If you aren’t too into making your own solution, definitely try this one out!
Give Your Plants A Shower – Spray Scale Insects With The Hose!
Sometimes you just need to give your plants a little shower to get rid of any insect infestations!
Spraying your plants, at a higher pressure than usual (but not too high, so you don’t damage the plants) will help get rid of scale insects on your plants.
Spraying your plants not only helps the plant gain back some hydration after a heavy scale infestation, but it will prevent any future scale insects from coming to your garden!
Hydrogen Peroxide Can Work Against Scale Insects
This Amazon Basics Hydrogen Peroxide can work against the scale insects of your plants! Mixing hydrogen peroxide and water in a spray bottle and spraying it directly onto problem areas can effectively get rid of the scale insects.
Hydrogen peroxide is an irritant to scale insects and acts as an insecticide.
Using hydrogen peroxide will not only get rid of the scale insects but stop the scale insects from spreading. Just make sure to test this on a small area of your plant first and notice the effect it has on the leaves.
Remove Singular Leaves If They Are Too Affected By Scale Insects
Another fool-proof way to remove scale insects is to actually remove the singular leaves that are affected by scale from the plant itself! Not only will this help save the rest of the plant, but it will also effectively get rid of any clumpy scale that you see on the few leaves they are on!
By grabbing garden shears like these 8 Inch Pruning Shears, you can easily cut off problem leaves, without having to put stress on the entirety of the plant.
Although many insecticides and the things we suggest are safe for your plant – adding anything to a plant will cause it a period of trauma, and it will need to recover. So, if you can prevent the whole production by just cutting off and getting rid of only scale-infected leaves – you’ll be golden!
Try A Pre-Made Insect Spray To Get Rid Of Scale Insects
However, when worst comes to worst – and all else fails, going in with a pre-made insecticide spray is going to be your best option for getting rid of the scale insects. Start with Garden Safe House Plant & Garden Insecticide and look at similar options if you don’t to go with any of the above choices.
Using an insecticide will be the most effective way to treat your scale infestation and using sprays like the above will not be harmful to your plants!
Repot Your Plant If Your Dirt Is Affected By Scale Insects
Lastly, after getting rid of your scale insects, it’s important to repot your plant so that it doesn’t spread any leftover insects, and that you’re offering it a clean space to regrow and thrive in.
Scale insects are teeny-tiny, so there’s a chance you could have missed one or two. Since that’s a possibility, repotting your affected plant will help it regain control, it will bring back new nutrients from the soil and will give the plant a space to fully recover, while doing your best to make sure that the dirt no longer has scale.
Use Essential Oils To Prevent Scale Insects From Coming Back
If you’ve gotten rid of scale insects, we suggest using different scented essential oils that the majority of insects hate – to keep them away for good.
Some essential oils you can use to get rid of scale insects are peppermint oil, clove oil, cedar oil, lavender oil, eucalyptus oil, and lemongrass oil.
All of these oils have very strong aromas and can be irritating to most insects. Moreover, these oils will mask the smells of food, predators, and host plants – which will confuse the insects and make them deem the area dangerous.
To use essential oils simply add a few droplets to cotton balls and strategically place cotton balls in high-scale insect areas. Or, you can add droplets of the essential oil directly to the leaves that scale insects were on, or to the soil around your plants.
What Do Common Scale Insects Even Look Like?
Scale insects are hard to spot – and it’s not just because they look like spots. There are a few tell-tale signs that you can use to identify scale insects like being in clumps on your leaves, looking like bumps, and staying in one spot.
However, not all scale insects look exactly the same. Remember, there’s over 8,000 species. But – they have similarities between the entire species that we’re going to talk more about below.
They Are Small
It’s true. Scale insects are teeny-tiny, and according to Iowa State University, the most commonly seen scale insects range in size from ⅛ inch to ½ inch. There are larger species of scale insects out there like the Diaspididae that can be up to ¾ inch but are not commonly found.
Although smaller-scale insects are very small, they make a huge impact on your plants and vegetation. They will suck all the nutrients from your plant and leave it with their “honeydew” which breaks down and turns the plant yellow.
Scale insects can really be considered parasitic insects, as they just will keep sucking the nutrients from the plant, while not offering any benefits.
They Are Round
Scale insects are mostly round to oval in shape, and kind of look like pill insects when they’re rolled up (roly-poly) – minus the legs, and the antennae – basically – they look like the rolled up, armored look of a roly-poly bug.
Scale insects are round, with a very hard appearance, which can be explained as looking like armor or a singular scale on a fish or reptile.
The scale insects give the appearance of scales on a leaf or plant, and although they are round, form in all-shaped clumps on your plants.
Scale Ranges From Tan To Brown To Black
Scale insects come in various shades of color, and may change their color depending on the stage of life they are in.
According to Washington State University, scale insects have 3 stages of life: egg, immature, and adult. When they are born, they are typically tanner in color, when they become an adult the females turn a darker brown to black color, whereas the males stay a tan to brown color.
However, these are only the colors of most of the scale insects out there. There are instances where scale insects can be white, gray, red, or even purple!
They Often Leave Your Plant Sticky
Scale insects leave a sticky residue behind on their host plants called honeydew. And no – it’s not the melon, so don’t taste it! This sticky, sweet substance is excreted from the scale insects and creates big problems for the plant itself.
The honeydew will actually turn leaves yellow, will cause them to wilt, and can completely deteriorate the entirety of the plant. This sticky substance attaches to plants, leaving them to ruin.
The honeydew is especially bad because once it’s on a plant long enough, it starts to create Sooty Mold which is a black substance that becomes a fungus on your plant. If your plant gets the Sooty Mold – it will surely need help to recover and will need to be treated immediately.
That’s A Wrap!
All in all, if you have scale insects – it’s time to remove them. Getting rid of scale insects, and using some preventative measures to keep them from coming back are important for the health and safety of your plants.
Let’s quickly go over some of the ways to get rid of scale insects:
- Manually scrape scale insects off of your plants
- Use Isopropyl Alcohol to get rid of scale insects
- Isolate your affected plant from other plants to stop the spread of scale insects
- Give your plants a shower – hose off any scale insects you may see
- Use Neem Oil as an insecticide to get rid of scale insects
- Use Hydrogen Peroxide to get rid of scale insects
- Cut off and remove scale-infested singular leaves from your plants
- Purchase ready-made insect spray to remove scale insects from your plants
These methods are all effective ways to get rid of scale insects, however, we always emphasize how important it is to contact a professional, especially when dealing with large amounts of insects.
Getting rid of the insects is typically easy, however, making sure they don’t come back can be challenging!
Culik, Mark P, et al. “Diaspididae (Hemiptera: Coccoidea) of Espírito Santo, Brazil.” Journal of Insect Science (Online), University of Wisconsin Library, 2008.
Uchegbu, M., Okoli, I., Esonu, B., & Iloeje, M. (2011). The grovving importance of neem (Azadirachta indica A. Juss) in agriculture, industry, medicine and Eenvironment: A review. Research Journal of Medicinal Plant, 5(3), 230-245.
García Morales, M., Denno, B. D., Miller, D. R., Miller, G. L., Ben-Dov, Y., & Hardy, N. B. (2016). ScaleNet: a literature-based model of scale insect biology and systematics. Database, 2016.
Zack is a Nature & Wildlife specialist based in Upstate, NY, and is the founder of his Tree Journey and Pest Pointers brands. He has a vast experience with nature while living and growing up on 50+ acres of fields, woodlands, and a freshwater bass pond. Zack has encountered many pest situations over the years and has spent his time maintaining and planting over 35 species of trees since his youth with his family on their property.
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