We are often asked whether my cactus suffers from spider mites. Usually as a result of seeing a web on the plant. In this blog we will show you how to recognize spider mites, but also how to distinguish a spider mite's web from the web of a normal spider. We also give you some tips about when they are active, which types of cactus and succulents are susceptible to spider mites and what you can do about them.
What is spider mites?
Spider mites are very small spider-like insects, often up to 1 mm in size. So they are really very small. But often many at the same time. They can also reproduce quickly and are therefore able to damage a single plant in just a few weeks. You often see many small damages/scars on the plant. This is due to the bite marks of spider mites. After a while, small, dense webs of a few centimeters in size also become visible.
When are they active?
Our experience is that this spider mite is mainly active in spring and summer. In the autumn and winter months we see almost no infections or spider mite activity on the plants. How come? Spider mites like dry and warm air. They really thrive on this and it is also one of their weaknesses to tackle. More about this later. In autumn, humidity is often higher and temperatures drop. In winter you see that the new eggs do not hatch due to the drop in temperature. These then wait for better conditions in the spring. That is why it is important that you check your cacti and succulents extra for spider mites, especially in the spring.
Is it a spider or is it spider mites?
We are often asked whether a plant suffers from spider mites because a web is visible. In most cases it is an ordinary spider that is also active in spring and autumn and finds the shape of your cactus or succulent plant perfect for making a web. A normal spider won't hurt your plant.
We have listed the most important differences below for you so that you can easily recognize them yourself.
| SPINTS | SPIDER |
| Max 1mm in size | Often a few mm to cm in size |
| Web is several cm in size | Often a large web |
| There are many on your plant | Often found alone in a web or plant |
| The web is blurry white to white-blue in color | Clear web lines visible |
| No insects hang in the web | Other insects can hang in the web |
| Clear trace of bite scars on your plant | Do not leave scars on your plant |
| You see many small dots moving | Barely moves |
How do I get spider mites?
That is a good question. Even if you've never had it, you can suddenly get it. The contact and source investigation of your spider mite infection is actually impossible. Spider mites like to hitchhike on the wind and land on your plants. But even if you have been near a plant with spider mites, it will hitch a ride on your hands and clothes.
What can I do preventively?
As mentioned earlier, spider mites like warm and dry air. What we do in the spring on warm days is mist the plants. You can do this with a brush attached to your garden hose or with a plant sprayer. Spiders don't like this at all and they will quickly choose to leave. Spider mites hibernate and like to sit in old, nutrient-poor soil. Repotting or repotting your plants every few years after an infection will help get rid of any stragglers.
Providing nutrients with trace elements during the growth period of your plants also helps. This ensures that your soil does not become nutrient poor and also helps keep your plants healthy. Healthy plants are also more resistant to spider mites. Therefore, carefully check your cactus and/or succulent that is not doing well or set it aside.
What can I do about spider mites on my plants?
If you have a lot of plants together, I would first separate the plants with spider mites and keep a close eye on the plants that were around them. You can mist the plants with a mixture of water, spirits and green soap. Ratio: 1L water, 20 ml spirit and 20 ml green soap. Preferably do this at the end of the day. Then the eggs hatch and you immediately take the youngest with you and you will not get burn marks from the sun in the summer. NB: This is not suitable for succulents with a wax layer such as some Echeveria, Pacheveria and Dudleya species. The green seaweed and spirits in the water affect their wax layer.
Another alternative that works well and that we are strongly in favor of is biological control by using the natural enemy. By using predatory mites against spider mites. This way you let them do the work and our experience is that they do this very effectively and fanatically. You can buy these online from various providers here.
Are there species extra sensitive to spider mites?
An advantage is that cacti and succulents are generally less sensitive or less popular with spider mites than other houseplants. But you still sometimes see them there. Some species that, in our experience, are popular with spider mites are: Orbea, Huernia, Lophophora and Euphorbia species. In addition, they are also more likely to choose plants whose resistance is reduced or that are weak compared to healthy, strong plants.
We hope to give you some clear guidelines, so that if you have any doubts you can see whether you are suffering from spider mites on your plant or whether it was a normal spider. Do you have any questions about the general care of your plant? Or maybe how to deal with care in the spring? Then read our other blogs. And if you still have any questions, please feel free to contact us.
