What is a red spider and how to prevent it?

What is a red spider? What are the hazards of red spiders and how to prevent them? Also ask the netizens who know to help introduce the red spider, also known as cotton spider mite, which is mainly harmful to the growth of corn, sorghum, legumes, sugar beets, melons, vegetables and other crops in the middle and later stages. Therefore, the farming web has sorted out the harm and control methods of red spiders, which are listed in detail below for netizens' reference. The harm of red spiders: red spiders mainly harm the leaves, stems and flowers of plants, suck the stems and leaves of plants, reduce the moisture of the damaged parts, lose green and turn white, and show dense pale spots on the leaf surface, curling and yellowing. In severe cases, yellow leaves, scorched leaves, rolled leaves, fallen leaves and death occurred in the plants. And the red spider is also the transmission medium of viral disease. Red spiders generally resume their activities when the temperature reaches 7 ℃ in early spring, feed on weeds or overwintering hosts for 1 and 2 generations, and move into cotton fields in early May. The damage of red spider is the most serious during the period of high temperature and drought from July to August. In the cotton fields with continuous cropping, extensive management, many weeds, close to the vegetable field and sandy soil, the occurrence of cotton leaf mites is early and serious. Red spiders like high temperature, and high temperature drying is beneficial to growth and development. The time needed for each insect stage is shortened with the increase of temperature at 15: 30 ℃, and the most favorable for the growth of spider mites at 20: 27 ℃. The control methods of red spiders: first, timely and thoroughly remove weeds in the fields, ridges and canals, reduce the food and breeding places of spider mites, reduce the number of insect sources, and prevent them from being transferred to the field. Method 2. Protect beneficial insects such as lacewings and ladybugs and make full use of natural enemies to control the harm of leaf mites. Method 3. When cultivating crops, we should irrigate reasonably to avoid over-drying. Method 4. Chemical control should be carried out in the early stage of the occurrence of red spider. 73% propargite 1000-fold solution, 25% acaricidal manganese 1200-fold solution, 20% compound Liuyangmycin 1000-fold solution, 20% dicofol 1000-fold solution and so on. Spray once every 7 to 10 days, about 3 times in a row. The focus of spraying is on the upper part of the plant, especially the young leaf back and tender stem, to increase the amount of spraying on the seriously affected points or plants in the field. How to make armyworm board? what is a grub?