What are spider mites?

Spider mites are a common pest of houseplants. Spider mites are arachnids which means they are related to spiders, ticks and scorpions rather than insects. The spider mite belongs to the family Tetranychidae. Some of these species form webs to protect their eggs and young from natural enemies.

There are super many different species of spider mites and although they come in different colors they are often difficult to see with the naked eye. They have a size between 0.2 and 0.5 millimeters, so a magnifying glass is useful to check if you are suffering from spider mites.

Spider mites begin their lives as eggs that adult spider mites lay on the so-called host plant. An adult can lay as many as 100 eggs in a three-week period. Unfertilized, the spider mite egg will become male. Fertilized eggs will become female, and it is usually about a ratio of 3 males to each female. Depending on the environment and the mite species, the eggs hatch into larvae within a few days or weeks. At this time, the larvae have only six legs instead of eight.

The larvae feed on the plant for a few days before turning into eight-legged nymphs. The nymphs feed for a few more days before changing to the second nymphal stage. This whole thing happens one more time, after which the nymph turns into an adult spider mite. So the mites only need a few days to complete each life stage. So in just one week they can grow from an egg to an adult, which means you suddenly have a big infestation! Most species of spider mites thrive on warmth, such as a nice warm living room. Although it may seem like they popped up out of nowhere, they may have been around your plant all along. It's also possible that they've hitchhiked in with you on shoes, clothing or pets. They can even blow in with the wind!

How do I recognise spider mites?

Spider mites are so small, chances are you won't notice the infestation until the plant is declining. The spider mite has a round or oval body that is usually less than 1 millimeter long. If you look very closely you can spot tiny spider legs. Do you have a magnifying glass? Then you can often see the younger spider mites and the eggs on the leaves.

When spider mites have been on the plant for a while, you will see that they destroy the cells of the plant. A single spider mite can destroy about twenty plant cells per minute by sucking the sap from the cells. Although the spider mites are on the underside of the leaves, you can often see the damage on top of the leaves. There are three main signs by which you can tell that you (may) be dealing with a spider mite infestation. Spider mites have sucking mouthparts that they use to slurp up plant juices from your plant. This leads to many small dots on the plant. When a lot of spider mites eat at the same time, and thus pierce holes in your plant, all the dots together will cause a discoloration of the leaves. You will see the leaves of your houseplant turn bronze, yellow or silver.

Another sign of spider mites are their thin webs. Once the population increases, the mites begin to form visible silk webs on or under the leaves and stems. These webs help distinguish them from other small pests, such as aphids and thrips. If you see small webs forming, it is recommended that you check the plant closely for spider mites!

Of course, your plant is not going to be happy if all its nutrients are sucked out of it. If the infestation really gets out of hand, the leaves will turn brown on their own and eventually die. If you really wait too long, the infestation can be fatal for your green friend.

Most spider mites need nice warm temperatures and low humidity. Your living room might just be the perfect place for the spider mite!

How do spider mites damage my plants?

A spider mite infestation can be subtle at first. It may seem like the plant is just taking a break. Sometimes you'll see little cobwebs that the spider mites strain on and between the leaves. It is only when you look really closely that you will recognize the spider mites. They are incredibly small! With the bare eye, spider mites look like red, yellow, black or brown moving dots.

A spider mite lives off the nutrients that flow through the veins of your plant. This vein system of a plant is called the phloem. The juices flowing through the veins flow through the phloem with considerable force. A spider mite drills a little hole, so to speak, with its snout, attaches itself to the phloem and is completely filled with nutrition without any effort! These tiny holes hinder the growth of your houseplant and cause discoloration of the leaves, usually in clusters. The result is reduced photosynthesis, which prevents the plant from continuing to grow nicely.

How can I prevent spider mites?

Prevention is better than cure, but unfortunately we cannot 100% prevent your plant from getting spider mite. However, you can take a few precautions to reduce the risk of this nasty pest. Spider mites travel with the wind and can also be found on your clothes. This makes us, unknowingly, the biggest spreaders of the pest! You should also make sure to inspect new plants, pots, or plant tools before you use them on your plantlets. Unfortunately, no matter how careful you are, there is still a chance of spider mite. Spider mites love a warm and dry environment. Old potting soil, for example, is perfect for breeding. By ensuring a higher humidity, a lower temperature in the house and every now and then a nice spray with the plant spray you can make your plant less attractive to the spider mite.

Care

A well cared for and healthy plant is the best protection against diseases and pests. Therefore, make sure that your plant is in the right location, gets light and water as needed and give it some extra plant food once in a while. To protect your plant against spider mites you should also make sure that your plant is not in a draught. Spider mites also simply blow in with the wind and see your green houseplant as the perfect landing strip! If an infestation should occur, the plant will be well cared for and strong enough to survive the attack. Cuttings and young plants often do not have enough strength yet to withstand an attack on their tender roots. If you suspect that you have a spider mite infestation, keep a super close eye on it and intervene as soon as possible!

How can I control spider mites?

Spider mites multiply quickly and therefore make your plant weak. If you suspect that your plant is suffering from spider mites, it is very important to take action immediately! Fortunately, there is no need to panic: Your green friend will not die instantly from red spider mite, but she will weaken, which increases the risk of other diseases and plagues. With cuttings and young plants it can go wrong quickly: they are not as strong as the adult plants. Put your shoulders to the wheel and try to start fighting right away!

If one of your plants is a victim of the plague, it is possible that other plants will also be infected. The spider mites can also jump to other plants. Therefore, put your infected plant in a separate room and away from your other plants. Fortunately, there are many natural methods to combat spider mites. With the following tips, we hope that you can get rid of this annoying animal quickly so that your plant can live happily ever after!

Fight spider mites with neem oil

Neem oil is a natural essential oil that works wonders in treating and preventing pests! Because of its smell, it has lasting effects on the plant. This wonder product is included in the PLNTSdoctor Kit. To ensure that the product "sticks" to the leaves of your plant, you mix the neem oil with water and natural detergent. Pour the mixture into a plant sprayer and apply it to the underside of the leaves. Reapply every few days until the spider mites are completely gone. Also, be sure to remove any dead insects once the oil has done its job. Stubborn clusters can also be dabbed with a cotton swab containing neem oil.

Neem oil can also be used preventatively to protect your plant from pesky insects, pests and fungi. Just be sure not to place the plant in direct sunlight afterwards. The oil can retain a little heat and can thus burn the leaves of the plant!

Ecokuur Leaf Insect Spray

This insect spray is an alternative to chemical pesticides. It is safe for humans, animals and the environment and therefore perfect for a simple way to combat your affected plant. Spray the product homogeneously over the plants where you have spotted the spider mites. Do not forget to include the underside of the leaves, this is where the spider mites are usually found! Treat from the moment you see the first insects and spray twice a week, with one week in between.

Fight Spider Mites with biological pest control

You could choose to fight off spider mites with biological pest control. The natural predatory mites are called ‘Phytoseiulus persimilis’. These bugs are effective and pretty fast. They will overpower the infestation in no time! The mites can’t be seen and eat about 6 adult spider mites or 20 young spider mites (eggs) per day. When there are no spider mites left to eat, they will eat each other and will disappear completely.

If you are interested in the topic of biological pest control, you might would like to read our blog: ‘Which natural and biological pest control against which pest?’

If you go online and look for the best way to combat spider mites you will come across many options. It is good to know that there is not one specific method that works for everyone. For some plants, one method works better than the other. It's just a matter of trying it out!

Below you will find a number of alternative hacks that will help you recognize and control spider mites.

Recognizing spider mites

Because spider mites are super small it is difficult to see them with the naked eye. Do you suspect that your plant is suffering from these pesky pests? Then take a piece of white paper and hold it under the leaves of your plant. Gently shake the plant. If your plant is suffering from spider mites, the spider mites will fall onto the paper. The specks on the paper look a little like pepper! To be sure that it is spider mites, you can always check with a magnifying glass.

Fight spider mites with methylated spirits

A home-garden remedy that is often used as a pesticide against pests is methylated spirits. Mix about 20 milliliters and 20 milliliters of biodegradable detergent with a liter of water. Spray the plant regularly with the soap mixture and the spider mites will eventually disappear completely.