What are the control methods for rapeseed aphids?

(Agricultural Wealth Network) 1. Chemical control. Start spraying when the rate of aphid-infested plants at the seedling stage reaches 10%, with a pest population density of 1 to 2 aphids per plant, or when 10% of stems, branches and flower clusters are infested with aphids during the bolting and flowering stage, with 3 to 5 aphids per branch. Generally 2 to 4 sprays. 2. Yellow board trapping to kill aphids. After autumn sowing, set up yellow boards at the edge of the rapeseed field. The method is to use a 0.33 sq m plastic film, coat it golden yellow, then apply a layer of petroleum jelly or machine oil, and set it up on a frame 0.5 m above the ground, which can trap and kill a large number of winged aphids. 3. Biological control. Pay attention to protecting natural enemies. Aphidius wasps, green lacewings, hoverflies and various ladybugs are important natural enemies of aphids.