How to control cotton aphid?

The cotton aphid sucks the juice from the back and tender head of cotton leaves with suction holes, which makes the cotton leaves grow abnormally and curl backwards. The harm of cotton aphid mainly occurs in seedling stage and bud and boll stage. Cotton aphids that suffer at seedling stage are called seedling aphids. Generally speaking, this damage will delay the development of cotton seedlings, leading to late maturity and yield reduction. When seriously damaged, cotton seedlings can not continue to develop or even die; The cotton aphid that suffered in the bud boll stage is called aphid, which will make the bud boll fall off, and some will lead to defoliation and yield reduction; Cotton aphid, called autumn aphid, sometimes appears in cotton boll opening period, which pollutes cotton boll and reduces cotton quality.

Carry out cotton-wheat rotation, use wheat barriers to prevent winged aphids from moving into cotton fields, promote the transfer of natural enemies of wheat to cotton fields, and enhance the ability of cotton field regulation and self-control. Many growers choose old-fashioned sprayers to control cotton pests and diseases. It is suggested to spray the leaves more evenly and thoroughly with sprayer and other equipment, or add a certain amount of silica gel to enhance the permeability of drugs. There must be enough water when taking medicine, which is subject to a drop of leaves. Anti-flying powder is not recommended. If the reaction force is too small, it will damage the top leaf and the effect is not good.

There are many kinds of natural enemies of aphids, such as ladybug, sandfly, syrphid, stinkbug floret, Aphid bee and Aphid Peak. When controlling aphids in wheat fields, selective pesticides that do not kill natural enemies are used to protect natural enemies from transferring to cotton fields. After cotton production is stopped in mid-July, if it rains continuously for 5-6 days and the temperature rises above 26℃ after the rain, aphid mold can be prevalent and aphid damage can be controlled. The most important thing to protect and utilize natural enemies is not to use drugs casually. If the ratio of ladybug to aphid is below 1 to 150, do not use the medicine.

The number of three-leaf aphids per 100 seedling is 2500, or the average number of three-leaf aphids per plant is 200 with the occurrence of leaf-rolling plants as the control index. When the cotton aphid reaches the control index, it is in the stage of spot damage. Local spraying should be carried out to avoid large-scale medication. Low toxicity and high efficiency pesticides, such as imidacloprid and acetamiprid, can be used. It can also be used to control the third generation cotton bollworm and aphid.