Звичайний павутинний кліщ (Tetranychus urticae)
The common spider mite is the most famous representative of the spider mite family. Its size depends directly on its nutrition. Sexual dimorphism of individuals is in size. Females have an average body length of about 0.5 mm, males are slightly smaller, about 0.4 mm. The spider mite is an arachnoid, which is characterized by 4 pairs of legs in adults and the production of spider coverings. By nature, polyphagous and cosmopolitan, omnivorous and inhabits everywhere except Antarctica. The fact that the spider mite is arachnid creates serious difficulties in combating it, because insect repellents are powerless in this case.
Stages of development
The animal has several stages of development (yes, it is an animal, not an insect, arachnids belong to the animal kingdom)
- egg
- a larva is green, light, or brown shades (six-legged phase of the mite)
- nymph
- an adult has red body, either pronounced or with the presence of shades
Unlike open ground, where mites do not pose a particular danger, due to changes in climatic conditions and precipitation, in greenhouses it is a dangerous rival. In the comfortable temperature conditions of the greenhouse, the spider mite egg can turn into an adult in just 7 days. At the same time, an adult individual can already produce offspring.
Spider mites feed on the sap of the plant, thereby weakening it. Damaged areas of the leaf turn yellow, which worsens the process of photosynthesis and the production of new nutrients. This leads to the death of damaged leaves, and if no action is taken, then a colony of mites in a few days can lead a small plant to death. During the defeat of the spider mite, fungal diseases are very often joined, which further complicates the life of the plant.
Infecting a plant with a spider mite is easy, they are carried by the wind, animals and people, and can also get caught in seedlings, because of their tiny size, they are almost invisible.
How to detect a mite?
The most obvious and sad stage is the web that envelops the plant. At first, it is invisible, but this does not mean that there is no mite.
The piercing-sucking apparatus of the animal is adapted to suck the juice from the plant. Bright spots appear at the site of punctures, which is already a signal to check the plant for the presence of a pest. The leaves of the plant can deform, change colour and fall off. Another signal is the black dots — the excrement of a spider mite.
How to deal with spider mites?
Folk remedies are ineffective in this fight. One of the best ways is to increase humidity by spraying with cold water. The spider mite does not like low temperatures, which slows down the process of its reproduction, as well as high humidity.
Chemicals require an integrated approach, because not all acaricides will bring results, and insecticides (insect repellents) are completely powerless. It is worth considering that the drugs do not destroy mite eggs, so after a few days, when new individuals appear, the treatment will need to be repeated. If you do not use an integrated approach and take into account the rate of reproduction, then you need to repeat the treatment repeatedly. Another nuance is the adaptation of mites to poison, that is, to get a result, it is necessary to vary the drugs.
Biological agents
Spider mite in nature has natural enemies. The main one among them is Phytoseiulus persimilis. It is a monophagous predatory mite, the basis of whose diet is just our pest spider mite. It destroys both adults and larvae and poses no danger to plants or humans. Also, suitable for this purpose is a predatory mite — Amblyseius swirskii. Despite the fact that it indirectly controls the mite population, it can be used in a comprehensive approach to control whitefly, mites, and thrips. It is extremely important to understand that predatory mites are very sensitive to acaricides, so in no case can both means of protection against the pest be used simultaneously. If you have already used drugs against spider mites, then you can start Phytoseiidae only after their effect ends.