Biological pesticides come from pests and pathogenic microorganisms and are very friendly to agricultural products and production environment. Biological pesticides for controlling Pieris rapae include abamectin EC, Bacillus thuringiensis solution and Bt wettable powder.
Pyrethroid insecticides have the advantages of high killing speed, high efficiency, low residue after application and safety. In order to control Pieris rapae, cypermethrin, phoxim and permethrin can be used.
Benzoyl urea pesticide is a new type of pesticide. There are many pesticides for controlling Pieris rapae, including Diuron No.3, flufenoxuron, teflubenzuron, diflubenzuron, chlorfenuron and so on. Please refer to the instructions on the package for the specific dilution concentration.
Pyrethrin, also known as natural pyrethrin, is an active ingredient with insecticidal effect separated from pyrethrum and internationally recognized as a pollution-free natural insecticide. When spraying 600 times diluted pyrethrin, Pieris rapae will show a strong reaction, the worm will be excited and crawl quickly, and then cramp and die. The whole process only takes 80 seconds.
Agricultural control method
After harvesting vegetables, it is necessary to thoroughly clean up the planting plots, remove the insect mouths on dead plants and leaves in time, and reduce the source of insects. In addition to paying attention to the prevention and control in spring and autumn, winter and summer can not be ignored, such as cleaning the countryside.
At the same time, the land can be thoroughly plowed to eliminate the eggs, larvae and pupae of pests attached to the soil surface, so as to reduce the population density of pests in the next crop; When cruciferous vegetables are planted in spring, it is best to choose varieties with shorter growth period, and combine with early-maturing cultivation techniques such as plastic film mulching to advance the harvest time of crops and avoid the peak period of pests.
The natural enemies of Pieris rapae include whitefly, Rabdosia rubescens whitefly, Trichogramma kwangsiensis, Lepidoptera, Vespa longipedunculata and so on. In production, we should actively protect and utilize the natural enemies of pests, and reduce the number of pests through the existence of natural enemies, thus reducing the harm of pests.
In the process of seedling raising, insect-proof nets can be set around the seedbed to isolate and cultivate seedlings to prevent adults from laying eggs on seedlings; Artificial killing of Pieris rapae adults and killing of larvae in cruciferous vegetables during the full flowering period of honey plants. Comprehensive control methods such as chemical control, artificial capture and protection and utilization of natural enemies should be adopted.
Refer to the above content: Baidu Encyclopedia-pyrethrins