Spider mites are tiny plant-eating mites, which look like spiders and ticks, to the naked eye, spider mites just look like red, yellow, black, or brown moving dots, attacking more than 180 types of plants. When it’s warm, they live and eat all the time, while in winter or cold regions they spend the whole time resting in the soil. Spider mites are most active in dry, hot environments and feed on the fluid that is drawn from individual plant cells using their needle-like mouthparts. Their presence in your landscape raises a red flag even though they don’t bite people or animals.
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Identifying Spider Mites
Spider mites are so tiny that a magnifying glass is required to see them clearly. Female mites are longer than male mites, measuring less than 1/20 inch.1 They appear as tiny moving dots to the unaided eye, but it is much simpler to see them as the webs that spider mites spin. These webs distinguish spider mites from other types of mites and other tiny pests that can infest plants, like thrips and aphids. Spider mites are present and actively feeding when webs are seen and plant foliage has tiny, discernible holes.
Always check new and old outdoor plants for spider mites on a regular basis. Check carefully for webs on the stems and undersides of the leaves, and keep an eye out for mites. Early detection of spider mites can help prevent severe damage and widespread infestations.
Spider mites, a bothersome pest, settle on our plants during the height of the summer. Their goal was to pierce and consume plant leaves.
The best way to guard your plants against spider mite damage is to be aware of the symptoms of an infestation, treat it, and take preventative measures to avoid further issues.
Signs Of Spider Mite Infestation
Since you won’t notice when spider mites arrive in your garden or home, the best weapon against a spider mite invasion is you, specifically your ability to recognize the tell-tale signs of an early infestation. If you notice any of these symptoms, be sure to carefully inspect your plants for spider mite infestation signs because they will become more obvious as the infestation grows.
Stippling: Spider mites typically live on the underside of leaves. They find shelter from the elements and a nice little spot to lay their eggs in the foliage, which they will do in just a few days!).
Plants are not bit by spider mites. In reality, they suck out the plant’s juices by squeezing into its cellular structure. Since the spider mites have started to gradually rob the plant of its chlorophyll, you’ll start to notice sparse patterns of tiny white dots on the leaves as they progress.
This will initially only affect a small area, perhaps just one or two leaves on a branch. However, as the mites move from leaf to leaf and branch to branch, the number of white spots will soon grow and start to appear on other nearby leaves. If untreated, those white spots will merge into one another so completely that you won’t be able to distinguish them from small, blotchy patches of decomposed plant matter.
Leaf Curl: Plants frequently curl their leaves in an effort to protect themselves when they are under stress. You’ll need to look closely to check for stippling on the plant’s foliage because there are a variety of causes for leaf curl, but when it comes to spider mites, stippling will first appear, and leaf curl will follow shortly after.
You should identify and eliminate spider mites as soon as you can for this reason, among others. Spider mites have even more protection in the plant’s curled leaves, which are a result of stress. In other words, the spider mites gain an advantage every day that a spider mite infestation is ignored.
Why? Because spider mites are delicate and perish when exposed to bursts of oily or soapy water. They usually conceal themselves on the underside of leaves because of this. The leaves shield the plants from dangers that could otherwise kill them.
Spider mite-infected plants are typically sprayed by gardeners (more on that below), but regrettably, curled leaves counteract the spray’s effects by preventing it from reaching hidden spider mites. The more crinkled leaves your plant has, the more cover the spider mites have.
They can reproduce more frequently as a result of the increased protection they receive, which increases the infestation and causes more curled leaves. As a result, the cycle not only continues but does so at an exponential rate.
Patchy, Decaying Foliage: You can tell when the stippling effect has spread to the point where there are no longer stipples but rather entire sections of the plant that have lost all of their chlorophyll by looking at white or brown patches on the foliage of your plant.
If you notice white patches anywhere on your plant, you need to take action right away because they will quickly turn brown and crusty as the plant’s leafy material dies and decomposes. You’ll observe a similar, albeit heightened, effect as leaves rot: dead foliage and decaying plants will make it more difficult for you to eradicate spider mites by putting up additional defenses against your treatments.
Pruning and discarding leaves are preferable once they have reached this stage of decay. You will get rid of hundreds, possibly even thousands, of spider mites from your plant by removing the infested foliage. Additionally, you’ll take down a barrier that separates you from the remaining pests.
Webbing: You most likely won’t see much, if any, webbing on your plant in the initial stages of a spider mite infestation. You’ll start to notice tiny, wispy threads in or around a few leaves and branches as spider mites multiply. Do not, however, mistake these for spider webs because spider mites are not spiders. Spider mites leave behind thin, silky clusters that are initially sparse but will increase in size and number as the infestation goes on, unlike spiders, which make webs that are intended to trap prey.
These webs have two main functions. First, they give the spider mites more protection, which increases their ability to spread to nearby leaves and branches. The second, and potentially most harmful, effect is that they give spider mites a way to move from one plant to another and from one garden to another.
Simply put, parts of these silky webs can be blown off plants and sent into the air in moderate to strong winds. Due to the wispy nature of their structure, the spider mite webbing can move from one location to another, transporting its passengers to different areas of your property or to other properties nearby.
It’s unclear, as far as I can tell, how far spider mites can move in this way. A localized infestation, however, could quickly spread across your property and onto the plants of your neighbors if the right circumstances and the spider mites’ reproduction rate were present. To prevent both localized and widespread spider mite infestations, take immediate action if you spot webbing. I’m hoping your neighbor will, too!
What Causes Spider Mites
Spider mites are able to easily invade our landscapes due to their size. You may have purchased outdoor plants from a garden center or nursery that have spider mites. Or the wind could have blown them in.
Due to the variety of plants they feed on, spider mites can also disperse quite quickly. Spider mites don’t have a particular preference for whether their prey is evergreen or deciduous, indoors or out.
How To Get Rid Of Spider Mites
Here’s how to treat spider mites in the summer or winter season:
- In the summer, a strong water spray will remove spider mites from your tree. At various points during the season, rinse your tree with a hose. The bottom of the leaves must be sprayed because that is where the spider mites are found.
- Use dormant oil to get rid of spider mite eggs that have settled on your tree during the winter or any time prior to the start of bud break in the spring. Less is known about how to give your tree dormant oil.
Knowing natural predators, i.e. what eats spider mites can also help. Rival insects like predator beetles or lacewings can help cut down on spider mite populations
How To Prevent From Spider Mites
1. Clean Those Leaves
Spider mites like dusty leaves on plants that are suffering from water stress. By periodically wiping off soiled leaves and making sure your plant receives the proper amount of water, you can deter them. You might occasionally try using a leaf shine as well.
2. Keep Humidity Up
Since spider mites like it dry, keeping the air humid around your plants is a great way to deter them from settling on your plant. Make the space more humid by using a humidifier, misting your plants occasionally, or placing a container of water nearby to evaporatively evaporate. Adding peat moss to the soil and using a sheer curtain to block direct sunlight from the room where your plant is growing are other options.
3. Debug For Departure
If you like to keep plants outside during the summer, make sure to take precautions to debug your plants before bringing them back inside.
Frequently Asked Questions
Can Spider Mites Spread To Other Plants?
Spider mites can move quickly between plants. Typically, they do this by flying through the air on a strong wind gust, hopping on clothing or tools, or crawling across interconnected foliage.
I’ve actually seen this procedure in action. A Brandywine tomato plant that I had next to one of my cherry tomato plants last year had an early stage of spider mite infestation. I crouched down to examine two entwined branches and spent a few minutes closely examining one of the more stippled leaves. To my surprise, two of the red dots appeared to be particularly active, and as I continued to observe, I noticed a red dot slowly move across the edge of a leaf that was touching another leaf. I continued to watch as it moved toward the second leaf because I was interested in what would happen. It took around 15 minutes, but during that time it was able to transfer from its first leaf to the second leaf.
In other words, a bridge had been created by the branches connecting the first and second plants, and the spider mite had wasted no time in utilizing it.
Clothes or tools may experience the same type of issue. Due to their size, spider mites can be unintentionally transferred from one plant to another while you are working in your home or garden. Since there is no way to tell if a spider mite has traveled from one place to another, the best course of action is to exercise caution when working around infested plants and to wash your hands, clothes, and gardening tools after coming into contact with a plant that appears to have a stage three or four infestations.
Spider Mites: Can They Crawl On People?
Spider mites can climb on almost anything, so transmission via skin or hair is also a possibility. Clothes are probably one way that spider mites spread from human to human.
By looking at a Purple Russian tomato plant that was infected last summer, I put this theory to the test. I looked at a few curled, broken leaves and found one of them covered in dozens of spider mites. I touched the leaf near the mites with the tip of my fingernail. I succeeded in squeezing a few mites onto my finger after doing so.
Regarding your safety or health, there is nothing to be concerned about. There is no evidence that spider mites can harm humans in any way, in contrast to their cousins the ticks, which are weak and easily killed. But when working close to plants that have different levels of spider mite infestation, you’ll need to be cautious.
What Can I Do To Stop The Spread Of Spider Mites?
To stop the spread of spider mites, you should first diagnose the stage of infestation, then take one of the following actions:
- Water: By literally blasting the spider mites off your plant with a water hose, you may be able to stop the spread of the infestation in its early stages. Spider mites cannot withstand a burst of water, so you must be careful not to harm the plant or spray the spider mites onto nearby plants. This method’s lack of use of chemicals or oils makes some people prefer it. Infested individuals have even been observed carrying their houseplants into the shower. I don’t think water is a particularly good remedy, though.
- Soapy Water: Add soap to your water and give your plants a good spraying to increase your chances of success. Spraying a soapy water solution on spider mites usually results in their demise. I advise mixing five tablespoons of a good insecticidal or Castille soap (like Dr. Make sure to cover the tops and bottoms of your leaves when applying the liquid soap (Dr. Bronner’s) with a handheld one-gallon pump sprayer.
- Soapy Water + Neem Oil: You’ll need to be more aggressive for stage two and three infestations by adding neem oil to your soapy water solution. If you thoroughly spray your plant with neem oil, you can kill spider mites by coating them, but failing to do so will only postpone the infestation. Make sure to use this remedy in the early evening. Your plants run the risk of being burned if you apply in the morning or late afternoon.
- Companion Planting: It is best to use a technique called companion planting, in which you place plants that spider mites prefer alongside plants that repel, resist, and also trap them. This will lessen the impact of spider mites once they have invaded your garden. By doing this, you’re establishing a natural barrier between plants that are vulnerable to spider mites and those that aren’t.