In recent years, small pests such as whitefly, thrips, mites and other small pests have become increasingly serious, and this type of pest reproduces quickly, the number is large, and the resistance is fast, and if you do not pay attention, there will be a large-scale outbreak in the shed, which has a great impact on the vegetables in the shed.
<h1 class= "pgc-h-arrow-right" >1, whitefly</h1>
Whiteflies are harmful vegetables and have two manifestations. First, due to its own secretion of honeydew, it often causes coal pollution disease in vegetable leaves such as eggplant, affecting the photosynthesis of vegetable leaves, resulting in a decrease in yield. Second, whiteflies are sucking mouthparts, which are important vectors for the transmission of viral diseases.
Life habits of whiteflies: The growth and development and reproduction of whiteflies are very much related to temperature and humidity. The optimal temperature for its survival is 20-28 ° C, and when it is above 30 ° C, the mortality rate of eggs and larvae is high, the life of adult insects is shortened, and there are few eggs laid, or even no reproduction. Experiments have shown that under the condition of constant temperature of 30 °C, the survival rate of whiteflies is only 14.69%,00%, while at 26 °C, the survival rate is 86.4%. Moreover, whitefly is a temperature-changing animal, and its respiratory rate will increase significantly when it is above 30 ° C, and it is easy to inhale more pesticides, which can greatly enhance the efficacy of pesticides.
In the spring, summer and autumn, the severity of the occurrence of whitefly is related to the external rainfall, especially in the summer, if there is more rain, the incidence of whitefly is light.
Prevention and control program: Most of the current spray insecticides are mainly touch killing, and a few pesticides have both fumigation and food refusal effects. Whitefly cling to the leaf back to suck the sap of the leaves, which is easy to form a dead angle that pesticides cannot reach, especially in the case of lush plant growth.
First, an aspirant agent is applied to the pit before colonization. For vegetable species that are susceptible to viruses, such as tomatoes and watermelons, insect control should start from seedling colonization. Because after the colonization of vegetables, especially after the colonization of autumn stubble vegetables, it is the period when the whitefly is seriously harmful, and only by starting from before colonization can we avoid the large number of whiteflies and spread the virus.
Moreover, when the whitefly is alarmed, it will fly to avoid, so that the touch killing effect of the liquid medicine is significantly reduced. Therefore, once the whitefly breaks out, it is difficult to rely on spraying alone to play a good prevention and control effect. Since the growth and development and reproduction of whiteflies are also very closely related to temperature, spraying combined with temperature or spraying should be adopted.
Temperature control method: the vent can be closed to ensure that the temperature in the shed is 1-2 hours at 30-33 ° C (it should be noted that the temperature should not be too high, and the time should not be too long, otherwise it is easy to produce drug damage), which can effectively improve the efficacy of pesticides and play a better control effect.
Whitefly have a strong tendency to yellow, and yellow armyworm plates can be set up in greenhouses to trap adult insects. Yellow plates can be purchased directly from the market or made in-house. Paint the cardboard yellow with paint, put on a transparent plastic bag, apply a layer of sticky oil (mix well with no. 10 oil and a little butter), and reapply the sticky oil every 10 days.
<h1 class="pgc-h-arrow-right" >2, thrips</h1>
Mainly in greenhouses, it harms crops such as eggplant, cucumber, kidney beans, peppers, and watermelons. Thrips use adults and nymphs to file the juice of vegetable shoots, young leaves and young melon fruits, and the young leaves and young shoots become hard and shrink, the fur becomes gray-brown, the internodes are shortened, and the growth is slow. for
It should be reminded that because the thrips are filing suction mouthpieces, they will not cause the "bright skin" of the peel when harming the fruit.
Adult thrips are good at flying and afraid of light, and are mostly harmful in the hairy bushes or flower trays or corolla between leaf veins or young shoots or young fruits.
Thrips have the habit of lying down at night, which is one of the reasons why thrips are difficult to control. When conventional contact killers are used, the insect body is not sprayed during the day. The peak period occurs in November-December in autumn or winter, and the second peak period occurs in March-July. Thrips prefer warm, arid weather, its suitable temperature is 23-28 ° C, suitable air humidity of 40% -70%; too high humidity can not survive, when the humidity reaches 100%, the temperature reaches 31 ° C, the nymphs all die.
Prevention and control plan: According to the characteristics of rapid reproduction and easy disaster of thrips, prevention should be the mainstay and comprehensive prevention and control should be carried out. If nutritious soil is used to raise seedlings and remove the diseased leaves of the residual plant, frequent watering can eliminate nymphs and pupae in the ground, and frequent weeding can reduce the harm.
It can be booby-trapped by using a blue plate, and during the thrips outbreak, when the dew is not dry in the early morning or in the evening, focusing on the parts of plants where thrips are easily moved.
<h1 class = "pgc-h-arrow-right" >3, mites</h1>
The most harmful vegetables in the greenhouse are mainly tea mites and diplodocus mites. The symptoms of mite pests are similar to viral diseases and hormone poisoning, and they are easily misdiagnosed by vegetable farmers. Mites, such as tea yellow mites are mainly harmful to the delicate tissues of vegetables, with the mouth needle to suck vegetable stems, leaves, fruits, in order to harm the growth points of plants and young fruits, after the harm, often cause the leaves and fruits deformed or split fruit, turn gray or brown; plant growth is hindered, growth weakening, seriously affecting the yield and quality of vegetables.
It is precisely because mites are mostly harmful to plant growth points, so their symptoms are similar to hormone poisoning or viral diseases.
The optimal temperature for mite growth and reproduction is 16-23 ° C, and the high temperature will shorten the life of adult mites and reduce their fertility. Humidity has little effect on adult mites, relative humidity above 40% adult mites can reproduce, but eggs and young mites have higher humidity requirements, relative humidity remain above 80% to develop. Therefore, a warm and humid environment is conducive to the occurrence of mites.
Control scheme: mites are mainly dimaculated leaf mites and tea mites, according to avermectin on the dimered leaf mite special effect, pyridoxine on tea yellow mite control effect is good characteristics, can be used 1500 times mixed with avermectin 2000 times spray treatment.