The role of insect net: 1. After the agricultural products are covered with insect-proof nets, they can effectively avoid the damage of various pests such as cabbage caterpillars, diamondback moths, cabbage armyworms, Spodoptera litura, flea beetles, beetles, and aphids. According to the test, the insect control net is 94-97% effective against cabbage cabbage caterpillars, diamondback moths, cowpea pod borers and Liriomyza sativa, and 90% against aphids. 2. It can prevent disease. Virus transmission can have disastrous consequences for greenhouse cultivation, especially by aphids. However, after the installation of the insect-proof net in the greenhouse, the transmission of the pests is cut off, which greatly reduces the incidence of viral diseases, and the control effect is about 80%. Insect-proof nets can avoid pesticides and make fruits and vegetables more green and healthy. 3. Adjust the temperature, soil temperature and humidity. In the hot season, the greenhouse is covered with a white insect-proof net. The test shows that: in the hot July-August, in the 25-mesh white insect-proof net, the temperature in the morning and evening is the same as the open field, and the temperature is about 1 ℃ lower than the open field at noon on a sunny day. From March to April in early spring, the temperature in the shed covered by the insect-proof net is 1-2°C higher than that in the open field, and the temperature in the 5 cm ground is 0.5-1°C higher than that in the open field, which can effectively prevent frost. In addition, the insect-proof net can block part of the rainwater from falling into the shed, reduce the humidity in the field, reduce the incidence of disease, and reduce the evaporation of water in the greenhouse on sunny days.