What are spider mites?
Spider mites (Tetranychidae) are tiny arachnids that are among the most common and persistent pests on houseplants, balcony plants, and garden plants. Due to their often reddish to orange-brown coloration, they are also known as small red spiders. However, there are also spider mite species that are more yellowish-green in color.
- Classification: Spider mites belong to the family of arachnids. They are assigned to the subclass of mites and the suborder Prostigmata.
- Size: With a size of only 0.2 to 0.5 millimeters, spider mites are tiny.
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Appearance: Their coloration varies from yellowish to reddish depending on the species and season.
In addition, spider mites reproduce extremely quickly. Females lay up to 100 eggs during their short lives, from which larvae hatch after just three days, developing into reproductively capable adults in only two weeks. Therefore, you should not hope that a spider mite infestation will disappear on its own. Quick action is crucial to prevent spread and greater damage to your plants.
Identifying spider mite infestation
Due to their tiny size, it is difficult to spot spider mites with the naked eye. However, there are some signs, especially on the plant itself, that indicate a spider mite infestation.
Spider webs on plants
The first sign of a spider mite infestation is usually the characteristic webbing. The formation of fine webs is typical, which often wrap around stems and shoots and are easily recognizable on houseplants.
It is important not to confuse these webs with normal spider webs on plants. Real spiders occasionally build webs on plants, but this is completely harmless. Spider mite webs appear finer and more delicate, almost like a thin white veil that clings tightly to the plant tissue. A spider web, on the other hand, is coarser, more three-dimensional, and usually stretched freely between two points.
Moving dots
Even if they are not always directly recognizable as animals, closer inspection often reveals tiny, moving dots – either in the webs or directly on the undersides of the leaves. If you discover spider webs on your plant, you should examine it more closely.
Weakened plant
Another sign of a spider mite infestation is a plant that appears diseased. Spider mites suck the cell sap directly from the plant tissue. As a result, the plant becomes increasingly weakened, and the leaves turn yellowish. In case of severe infestation, the leaves may curl, dry out, and eventually fall off.
Effectively combating spider mites
Without timely intervention, the plant can be severely damaged or even die. Therefore, it is important to act quickly to curb the spider mite infestation and save the plant. You can combat spider mites with these measures:
- Isolate the affected plant: Place the infested plant separately from other plants to prevent contact and spread between plants. Adjacent plants should still be treated as a precaution.
- Shower the plants: A simple and effective step is to thoroughly shower the plants. Place them in the shower and rinse them off. This washes off the pests and simultaneously increases humidity.
- Treat the plants: Chemical pesticides can be used for targeted control. However, these agents should be used with caution as they can also harm the plant. Natural alternatives are a better choice.
Home remedies against spider mites
There are various effective remedies you can spray on your plants to combat spider mites. A gentle and simple method is a mixture of rapeseed oil, water, and a few drops of dish soap. Neem oil, diluted with water, has also proven to be an effective alternative. Another remedy for spraying plants is a soap solution made from mild soft soap and water. Thoroughly spray the affected plants with the solution, especially the leaves and undersides of the leaves. Repeat the application every two to three days over a period of at least two weeks to combat the infestation sustainably.
Using beneficial insects
Beneficial insects such as predatory mites or lacewing larvae are natural enemies of spider mites and an environmentally friendly method to control infestations. The beneficial insects eat both the spider mites themselves and their eggs and larvae. For the optimal use of beneficial insects, it is important to consider their specific requirements for temperature and humidity.
Prevention: How do spider mites occur?
To prevent a spider mite infestation from the outset, it helps to understand how it occurs in the first place. Spider mites love warm, dry conditions and thrive particularly well in heated indoor spaces where humidity is often low. They often enter the home via newly purchased plants, cut flowers, or even clothing. Weakened or stressed plants are particularly susceptible. So, those who take good care of their plants make it harder for the mites from the start. Here's what you can do to prevent spider mites:
- Increase humidity: Regularly spray your plants with water or place a bowl of water nearby.
- Isolate new plants: Newly purchased plants should first be carefully inspected and, to be safe, placed separately from your other plants for a few days.
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Fertilize regularly: Well-nourished plants are more resistant. Fertilize your plants regularly to keep them strong and healthy.
- Check regularly: Those who observe their plants carefully will spot initial abnormalities early and can intervene before an infestation spreads and spider mites cause significant damage.
