Recently, with the gradual increase of temperature, the occurrence of some insect pests such as aphids and aphid shell insects has slowed down, but as a garden maintenance staff, our conservation management work cannot be relaxed at this time, because the harm of red spiders begins to peak as the temperature is getting higher and higher.
The picture shows the red spider
The red spider is a very common stinging pest in the garden, commonly known as the big spider, the big dragon, the sand dragon and so on. Red spiders are very serious in the north and south of China, and the distribution is very extensive; and the diet is more mixed, which can not only harm a variety of crops, fruit trees, vegetables, but also cause serious harm to many garden plants.
<h1 class="pgc-h-arrow-right" data-track="40" What are the hazards of red spiders to garden plants in >? </h1>
The picture shows the harm of red spiders to the leaves of the national locust
In the garden, the red spider mainly harms the safflower sorrel grass, jasmine, hairy rhododendron, moon season and other grasses and flower shrubs, as well as small trees such as osmanthus flowers, begonias and citrus.
Because the harm of red spiders is to suck the juice in the leaves with the mouthparts, so that the chlorophyll is destroyed, so the garden plants that are harmed by it will often be white and green in the early stage of the harm, and many small white dots will appear; in the later stage, they will begin to show gray-yellow spots or patches, photosynthesis is seriously affected and cannot carry out normal metabolism, and the growth trend is gradually weakened; if it is not prevented in time, it will cause the leaf to wither, fall off or die when the light falls.
The picture shows the fallen leaves of the national locust caused by the red spider
<h1 class="pgc-h-arrow-right" Data-track="39" What are the difficulties in the prevention and control of red spiders >? </h1>
1, the breeding speed is too fast.
The picture shows the harm of red spiders to the moon season
Red spiders can occur in 13 generations a year, mainly as eggs or fertilized female mites overwintering in cracks in plant branches, deciduous leaves, and soil cracks in the shallow soil layer around the rhizosphere. Hatching begins in early March of the following year when the weather warms up, and in early April, all hatching is completed and the hazard begins. It reaches its peak in mid-May, and as the temperature rises, it peaks throughout the year from July to August, especially from late June to early July. The leaves of the whole tree are often yellowed and white, and the wintering begins after late October.
It takes an average of 10 to 15 days for the red spider to complete a generation, and the fastest time is about 5 days to reproduce a generation; and it can also camp both sexual reproduction and parthenogenesis, the female mites only mate once in a lifetime, and the male mites can mate many times.
Therefore, the reproduction rate and number of red spiders are very large, which makes it very difficult for the control of red spiders.
2. The phenomenon of generational overlap is serious
The picture shows a red spider in various forms
Due to the rapid reproduction rate of red spiders and the serious phenomenon of generation overlap, there are often four forms of eggs, young mites, mites and adult mites on one leaf of the endangered plant. When it comes to drug control, it is difficult to find a mite drug that is effective against all four forms of red spiders at the same time.
3. The activity is relatively hidden
The individual of the red spider is very small, often less than 1 mm, plus it likes to hide on the back of the plant leaf to suck sap, so it is difficult to be found in the early stage of harm, and when the leaf front shows symptoms, often the situation is more serious at this time, so that we miss the best control period.
In addition, the red spider will also spit silk cocoons, so that the drug can not be well contacted with the insect body, so that the drug can not achieve the best control effect.
4. Strong resistance
Because red spiders reproduce faster and occur in large quantities, they often need to use drugs frequently when controlling; if the same drug or similar drugs are used frequently, the resistance of red spiders will become stronger and stronger, making the control effect worse and worse.
<h1 class="pgc-h-arrow-right" data-track="19" how can we do a good job in the prevention and control of red spiders >? </h1>
The picture shows the leaves of the national locust after being harmed
1. Strengthen daily management
In the daily garden maintenance and management work, it is necessary to pay attention to reasonable pruning to enhance the ventilation and permeability of plants. Rational application of phosphorus and potassium fertilizers makes the resistance of plants stronger.
In addition, when red spiders are found to be harmful on the leaves of plants, the affected leaves should be removed in time and taken out of the park for destruction, and then sprayed with drugs for control.
2. Grasp the timing of prevention and control
For most red spiders, they are high temperature active. The level of temperature determines the development cycle, reproductive rate and yield of each insect state of the red spider, and the dry and hot climatic conditions often lead to its large occurrence. Therefore, it must be prevented in time before the arrival of the high temperature and drought season.
Therefore, in order to prevent the large-scale outbreak of red spiders, in addition to the prevention and control of red spiders during the incubation period in early March, a drug control should also be carried out before the large-scale outbreak of red spiders at the end of June and the beginning of July.
3. Choose the right agent
In the selection of agents, you can choose a kind of insecticide compound of avermectin and pyridoxine, because avermectin has a touch and gastric toxicity effect, and the quick-acting is good; while the pyridoxine is a broad-spectrum tactile acaricide, which has a better control effect on eggs, young mites, mites, etc.
The compounding of the two not only avoids the rapid development of resistance of pests using drugs, but also expands the insecticidal common. It has a good control effect on various forms of red spiders.
It should be noted here that in order to achieve a better control effect of the drug, in addition to spraying insecticides during the control, we can also use foliar fertilizer and osmotic agents to increase the efficacy of the drug and also help the garden plants to recover their vitality and landscape ornamental effects as soon as possible.
New method of prevention and control: root irrigation control.
Root spraying can effectively solve the problem of difficult to spray drugs uniformly due to the tall trees, and it can also solve the pollution caused by chemical spraying to the surrounding environment.
The principle of root irrigation insecticide is that after burying or irrigating drugs at the root of the seedling, the drug can be transmitted to the branches and leaves of the aboveground part of the seedling with the absorption of the root system of the seedling, so that the whole plant can carry the drug, which in turn plays an insecticidal role. (Taking 10% imidacloprid as an example, a 15 cm chest diameter of the tung needs about 30 grams of water to irrigate the roots)
Key considerations for root irrigation control:
1. In the early stage of harm, it is necessary to use endorbent insecticides for irrigation in time.
This is mainly because root irrigation control is absorbed through the root system, and it takes a certain amount of time (about 10 days) for the drug to be absorbed from the roots to the branches and leaves transported to the aboveground part of the seedling. Therefore, when we find that a small number of red spiders begin to harm the leaves of trees, we can irrigate medicine, do not wait until the national locust is seriously endangered before irrigating the roots, so it is often a little late.
In the period of serious harm of the tung, it is not only necessary to administer endoric insecticides at the root, but also to spray permethrin insecticides in the tree part, so as to achieve the dual effects of rapid prevention and long-term prevention.
2. Root irrigation can not only control reticulum bugs, but also control other stinging insects.
Root irrigation drugs not only have a good control effect on red spiders, but also have a significant effect on other types of stinging insects. In order to make the efficacy of the drug better, the ratio of the drug (g) to the water (kg) is generally 1:5 when the drug is compared, so as to ensure that the drug can be absorbed by more roots, and the concentration of the drug when transported to the branches and leaves of the seedlings can also kill the pests.
Well, the control method of red spiders will be briefly shared with you here today.
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