How to prevent pests from developing drug resistance?

In recent years, due to the extensive use of chemical pesticides and the lack of basic knowledge of pesticide use by many flower farmers, improper drug use has led to more and more species of drug-resistant pests on flowers and trees, and the degree of drug resistance is also getting higher and higher. The following methods can be used to prevent the development of drug resistance of flower and tree pests.

I. alternate use of drugs

Do not use a single pesticide to control certain pests for a long time, so that the formation process of drug-resistant populations of pests can be cut off. The varieties used in rotation should choose pesticides with different action mechanisms as far as possible. Such as organophosphorus pesticides, pyrethroid pesticides, carbamate pesticides, biological agents pesticides and so on. If the insecticidal principles are different, they can be used alternately. The rotation of the same kind of pesticides should be used cautiously, because pests are easy to acquire cross-resistance, that is, resistance to a certain pesticide will also produce resistance to other varieties of the same kind of pesticide. For example, dimethoate-resistant chrysanthemum aphids are also resistant to dichlorvos and trichlorfon.

II. Mixed use of drugs

The mixed use of two pesticides with different modes and mechanisms of action can slow down the occurrence of drug resistance of insect pests, even if the drug resistance has been formed. At present, the successful schemes for mixed use of trichlorfon, dichlorvos and malathion, pyrethroid insecticides and organophosphorus insecticides, trichlorfon and phoxim, engine oil emulsion and organophosphorus insecticides, etc. Note: mixed pesticides can not be used alone for a long time, the use of drugs should be rotated, otherwise it will also cause drug resistance and even lead to multi-resistance of pests.