The Content Of The Article:
- What conditions do spider mites like?
- Which plants are affected?
- Disadvantages of chemical control
- What are predatory mites?
- This is how predatory mites help against spider mites
For spider mites, the underside of the plant leaves provide access to nutritious treasures. They sting one cell after another and suck her life juice until it is completely empty. The emptied cell fills with air. Together with adjacent empty cells, it is perceived as a bright spot. If this area gets bigger, it shimmers slightly silvery. Cell by cell, the green leaves lose their natural color, turn brown at some point and finally die. Unlike an aphid infestation, there is no sticky coating. That's because they do not suck on the sugary sap. However, they form a very fine web on the underside of the leaf, which spreads as the infection progresses. Finally, the spider web can even cover the entire plant.
Note: An exception are the fruit tree spider mites, these hardly form nets.
What conditions do spider mites like?Dry and warm air is the ideal environment for spider mites. Especially in winter, the dry heating air promotes their explosive propagation. They then often make their way over houseplants. It is therefore useful in winter to examine the leaves of all plants regularly for spider mites. If the plants are still close together in their winter quarters, the spider mite effortlessly wanders from one plant to the next.
In summer, the spider mite occurs in dry and hot weather in the field. If you have many warm and dry days together, you should keep an eye on your plants and regularly inspect the leaf undersides for spider mites.
Which plants are affected?Spider mites are not food deviants. They have been spotted on almost every plant. However, spider mites, just like us humans, have favorite foods that they are particularly likely to fumble with. Cucumber and bean leaves are often sucked out in the garden. On hot summer days, fruit trees must count on their visit. When it comes to indoor plants, citrus plants are very popular with the spider mite.
Disadvantages of chemical controlSpider mites go through various stages of development until an egg has become a full-grown spider mite. In a rest period between two stages, their food intake is limited. At such a stage, they can fight badly because they do not absorb the toxic substances of the insecticides in sufficient quantity. The treatment must therefore be repeated several times to make it successful. This and also the harmfulness of chemical substances to the cycle of nature, is causing more and more gardeners to look for other, biological alternatives. Predatory mites are one such alternative.
What are predatory mites?Predatory mites are also small arachnids, which are approximately the same size as spider mites with a size of about 0.5 mm. Her body is pear-shaped and yellowish to reddish brown. For our plants, predatory mites pose no danger because they do not suck their sap. They are interested in the spider mites, which serve as food for them. Therefore, the predatory mite is a natural enemy of the spider mite, which makes it beneficial for us humans.
This is how predatory mites help against spider mites
- Already in the early stages of infestation act
- Use predatory mites in sufficient numbers
- Relieve predatory mites immediately after delivery
- different species require different conditions
- Follow the instructions of the breeders / suppliers
- Give the beneficials directly to the leaves of the infested plants
- ensure good humidity
- If necessary, add a new "portion" of predatory mites after about seven days
If the infestation is already very advanced and also already numerous webs are to be seen, is for this biological control method already too late. Therefore, it is a good way to use predatory mites as early as spring, when the spider mites awake from their hibernation. The freshly hatching spider mites are thus prevented from spreading from the beginning. This procedure is especially recommended if plants are grown on a large scale. If it is still the favorite plants of the spider mites, the early use could secure the harvest.
Note: Chemical control agents such as fungicides and insecticides are harmful to predatory mites and should not be used in parallel.