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How to control Tetranychus: divided into prevention, treatment, special

Tetranychus Tetranychus, which is often called red spider, is between 0.4 mm and 0.5 mm in size. It is a pest that sucks plant juice. It attacks the bottom of leaves and sucks plant juice to make plants lose vitality. When plants are seriously damaged, the leaves will fall off completely. Today, let's learn about the experience of Huayou in controlling Tetranychus!

How to control Tetranychus

As shown in the figure above, if we find many small white spots on the leaves, and the plant leaves are withering day by day, you can turn over the leaves to see if there are many tiny spider like insects on the back. At the same time, there are often a lot of spider silk like silk screen, then it can be concluded that it is Tetranychus. Because in some specific conditions, the mite larvae can drill into the petiole or stem. The female adult of Tetranychus Tetranychus inserts the leaf with ovipositor, pricks out many small holes in the leaf, and produces single, translucent, white oval eggs, which is the reason for the appearance of small white spots on the leaf. How to prevent and control Tetranychus: first of all, Tetranychus like high temperature and dry environment, so in high temperature and dry climate conditions, it will breed rapidly and produce diseases and pests. At the same time, this pest has strong reproductive capacity, can also parthenogenetic reproduction, and has a strong resistance, the same drug used many times is very easy to fail. The owner of the building has tested many kinds of pesticides, such as: shishiheji, avermectin, ivermectin, propargite, spirodiclofen In addition, Huayou also tried biological control, that is, the use of natural enemies, such as predatory mites (e.g. Amblyseius cucumeris), summed up the following experience.

How to control Tetranychus

1、 Prevention

Because Tetranychus Tetranychus has a strong reproductive capacity, but also has a strong resistance, so we must focus on prevention and control. Most of the leaf mites occur in hot summer, so we should take preventive measures in autumn, winter and spring.

1. Drug prevention

Lime water: this method is mainly aimed at woody plants. In late autumn, when the fallen leaves of plants enter dormancy, timely clean up the dead leaves and weeds and the dead bark of the trunk, and then brush the trunk with lime water, so as to kill the parasitic eggs on the surface of the trunk.

Sulfur powder: in late autumn, clean up the dead branches, rotten leaves and weeds on the soil surface, then evenly sprinkle a small amount of sulfur powder (recommended use: sublimated sulfur and edible sulfur), and turn the soil to make sulfur evenly spread in the topsoil.

Stone sulfur mixture: this medicine is a special insecticide and bactericide used in China for thousands of years, but the side effect is that it will poison some sensitive plants. Therefore, it should be carried out after the dormancy of plants in late autumn, diluted with 300 ~ 500 times of the mixture powder, and then evenly sprayed the trunk of woody plants (not recommended for herbaceous plants), and evenly sprayed the soil surface to 0.5 ~ 1cm surface soil.

Spirodiclofen: in early spring, take 20% emulsion of spirodiclofen, dilute it with 4000-6000 times solution, evenly spray the front and back sides of leaves and branches, and irrigate the roots.

2. Biological prevention

Predatory mites: the common predatory mite is "Amblyseius cucumeris", and the common one on the market is in paper bags. Generally, mites are released in spring and early summer when mite damage has not occurred, and the releasing time should be in cloudy day or evening (rainy day should be avoided). The release mode of woody plants: large trees can nail the paper bag directly on the trunk; herbaceous plants or small woody plants can be directly fixed in the leaves or branches with pins or clips. The effective period of each bag is generally one quarter.

Inside the circle is the spider mite

2、 Treatment

Washing powder: if a small amount of Tetranychus mites is found in early season, a small amount of washing powder can be used (the concentration is enough to stir and froth), and evenly spray the front and back sides of leaves and branches of the plant.

Avermectin / ivermectin: 2% EC diluted with 1500-200 times solution, 5% powder diluted with 3000 times solution (there are many kinds, according to the instructions), evenly spray the front and back sides of plant leaves, branches, and roots (continuous use shall not exceed 2 times).

Spirodiclofen: take 20% emulsion of spirodiclofen, dilute it with 4000-6000 times solution, evenly spray the front and back sides of leaves and branches of plants, and irrigate the roots (it shall not be used more than 3 times per quarter, and the effect is 3 months after spraying, and it is waterproof).

Propargyl mite: take propargyl mite 56% emulsion, dilute it with 2000 ~ 4000 times solution, evenly spray the front and back sides of leaves and branches of plants, and irrigate roots (this drug generally does not produce drug resistance).

Spirodiclofen and propargite: if there is a large outbreak of Tetranychus, please mix it in the same solution according to the above dilution requirements, evenly spray the front and back sides of the leaves and branches of the plant, and irrigate the roots (absolutely no drug resistance).

Tetranychus

3、 Special section

Sometimes, when the spider mites have nothing to eat, they even eat succulent plants, such as staghorn Begonia and branch apricot. The results showed that spirodiclofen and propargite diluted 4000 times had no harm to foliage spray or root irrigation.