What are the advantages and disadvantages of chemical pesticides to control pests?

Chemical control is the key technical measure of integrated pest control system. Chemical control is effective quickly, and it can control a large area of serious pests and diseases in a short time. Generally, it can achieve a fairly high control effect on most pests and diseases, and the effect is stable. When pests and diseases are about to break out, only chemical control can play an emergency role. In forest pest control, some must be controlled by chemical control. At present, the main problems in chemical control are: ① environmental pollution. The use of pesticides has adverse effects on people and animals and the surrounding environment; The use of non-degradable pesticides leads to excessive residues in grains, fruits, soil, water and crop straws, which threatens human health. (2) Insect resistance. The directional selection caused by long-term use of the same pesticide makes the control object resistant, thus reducing or losing the control effect. ③ Kill beneficial organisms. Except for a few pesticides, most pesticides have a great killing effect on pests and their natural enemies. Long-term use of such pesticides weakens the control effect of natural enemies on pests, and even leads to more pests to be treated, which makes the farmland environment fall into a vicious circle.