Red spider is one of many strawberry insect pests, high incidence in the flowering period, its harm is large, the prevention and control will not be timely strawberry plant dwarfing, serious cases will also lead to strawberry yield loss of 25-40%, in addition, will also lead to small fruit, poor quality, deformed fruit, then strawberry red spider insect pest how to control it?
<h1 class="pgc-h-arrow-right" data-track="6" > strawberry red spider</h1>
Red spiders are also one of the important pests of strawberries, with high frequency and serious harm. The red spider is very small, and it looks like a small red dot to the naked eye. The red spider is a sucking mouthpiece. Prefer to suck sap on unexplored young leaves or the back of leaves.
Red spiders reproduce very quickly in high temperature and dry climates, and can breed more than 10 generations in a year. Female adults overwinter in the soil in the open field, lay eggs the following spring, and begin to be harmful after hatching. In greenhouses or greenhouses, breeding can also take place in winter, or overwinter on the back of old leaves.
< h1 class="pgc-h-arrow-right" data-track="65" > symptoms</h1>
Strawberry leaves are gradually scorched and shed, and the plants are short and grow slowly. Among them, the strawberry plants that were killed were dwarfed and prematurely aged, and the leaves showed reddish-brown dryness symptoms; during the flowering period of strawberries, they were endangered by red spiders, and the strawberry fruits shrank and stiffened, and the deformed fruits were often more, which would seriously affect the yield and quality of strawberry fresh fruits
<h1 class="pgc-h-arrow-right" Data-track="66" Why is the red spider difficult to fight >? </h1>
The red spiders that harm strawberries are mainly dichophyllum mites. It is small, adaptable, overlapping generations, and reproduces quickly.
1. Hidden in the leaf back: The red spider is very small, you have to look carefully to see, and also like to hide in the leaf back to suck the juice, and when the leaf front shows symptoms, the situation is often more serious.
2. Spit silk cocoon: A large number of red spiders spit silk cocoons can defend against pesticides and bad environments, which is also one of the reasons why red spiders are difficult to cure.
3. Strong drug resistance: long-term single use of a few acaricide varieties and the pest mites to produce drug resistance or drug resistance enhancement.
4. Safety issues: The flourishing period of red spiders is the flowering and fruit setting period of strawberries, so the safety of flowers and fruits, bees and humans should also be considered for spraying.
<h1 class="pgc-h-arrow-right" data-track="67" > the time point of prevention and control of strawberry red spiders</h1>
First, the spread of red spiders
1. Mainly seedling transmission, although the open-air seedling land occurs slightly, it is difficult to eradicate;
2. Greenhouse residue: Usually the high temperature is stuffy, and the shed temperature is above 60 ° C, which is enough to kill them. At this time, there are no green plants in the shed, it has no food, and after 10 days, the eggs left on various corners must be dehydrated and die at this temperature, or they will become young mites, and then there is no food, and they will starve to death. Therefore, it is wrong to say that if there is a high temperature and stuffiness, it is also necessary to penetrate the back wall;
3. After entering the shed: mainly artificial transmission, more importantly, artificial transmission in the process of leaf splitting. It is recommended to put the leaves directly into the bucket after splitting the leaves, and the inner wall of the bucket is a little better, and it is concentrated to bring out the greenhouse.
Second, the red spider prevention and control node
1. An important time node in the early stage of transplanting: after the first leaf splitting;
2. Time node before lamination: as needed, after each leaf splitting;
3. The time node of the whole season: before the last split of leaves before the mulch, after the mulch, after the opening of spring, and the interval between the two stubbles of flowers and fruits.
If it is a strawberry seedling bought, usually the seedling merchant pays attention to the prevention and control of the red spider, so even if there are insects, there will not be more, so when the first split leaf in the early stage of transplanting, the number of red spiders is less, although the temperature is still high at this time, but because the slow seedlings need to be often moisturized, it is not conducive to the development of red spiders, and everyone knows that the fewer red spiders are, the better the defense, so after the first split leaf, it is the first key point.
After transplanting - before the mulch film, whether it is necessary to control every time, you can find out whether there are small yellow dots on the leaf surface of the newly formed leaves as needed, and if there is, control it.
There are 3 season points, which have been described above. The most important thing is that before and after the mulch film, it will blossom and bear fruit, and the leaf volume will gradually increase, and the last opportunity to penetrate the strawberry will be lost.
<h1 class="pgc-h-arrow-right" data-track="71" > how strawberry red spiders should be controlled</h1>
1. Environmental regulation
Strawberries during the flowering and fruiting period need a higher temperature during the day, and the temperature should be adjusted to a lower level under the condition of ensuring the normal growth of the plant, generally 25 ~ 27 ° C. The temperature requirements at night are low, generally 10 ~ 12 ° C, such temperature conditions are conducive to the prevention of red spiders. Since the flowering period requires a dry air environment, in order to ensure the occurrence of no deformed fruits, the air humidity is generally about 40%. Drying is an important reason why red spiders are prone to reproduction, so in the management method of water, under the premise of maintaining soil moisture, when the temperature is too high, ventilate as much as possible, water and cool down, and inhibit the rapid growth and reproduction of red spiders. It is necessary to remove the old leaves in time to eliminate the source of insects.
After strawberry fruit set to before coloring, the indoor humidity should be appropriately increased by about 65%, and the air, ground and leaves can be atomized and humidified once. Increase humidity to prevent the occurrence and spread of red spiders.
After strawberry coloring, in order to prevent the rot of the fruit, the indoor temperature and humidity should be reduced to ensure that the temperature is between 23 and 25 ° C, and the humidity is about 50%.
Ensure that the soil moisture is sufficient, and the amount of watering with drip irrigation can be appropriately too large, and if there is an uneven phenomenon, manual watering will be carried out. Avoiding drought can also appropriately reduce the occurrence of red spiders.
2. Strengthen plant management
Timely removal of the bottom of the yellow leaves, old leaves, diseased leaves and disease residues, in order to ensure adequate nutrient supply, you can apply sea spirit biological stimulants 200 to 300 times the liquid, promote balanced absorption of the root system, improve the resistance of plant stress. Once a small number of plants are found to have red spiders, they are immediately treated, and all the plants with red spiders are moved to the same area to remove all their flowers and fruits.
3. Biological control
The use of predatory mites to carry out control, such as California's blunt mites, intellectual small plant mites, etc., generally a leaf on top of a predator mite, you can effectively control the red spider. However, the effect of predatory mites is slower, and if the outbreak of red spiders is more serious, it is still necessary to focus on drug control.
4. Drug prevention and treatment
When a red spider is found, make sure to address the source of the insect and block its spread to other plants. Recommended drugs: biphenylhydrazide, ethanazole, thiazone, gram mite, spironate, etc. are used in rotation.