What harm does corn aphid have to corn? What kind of medicine should be used for prevention and treatment?

Aphids are widely distributed in the world, mainly concentrated in temperate regions, is one of the most destructive pests on the earth, harming most crops, and its destructiveness is more obvious in corn. So, what harm do corn aphids do to corn? What kind of medicine should be used for prevention and treatment?

First, what harm does corn aphids have to corn?

The survival of corn aphids depends on the ants in the cornfield. The eggs are stored in the nest by the ants in winter. In spring, the eggs are moved to the grass root and then transferred to the corn root. Adult aphids and nymph aphids are harmful to the heart leaves of maize at seedling stage and to ears after heading, which absorb sap and hinder growth, and can spread a variety of Gramineae cereal viruses. As the plant grows, the damage is concentrated on the new leaves. At booting stage, it is harmful to concentrate in the flag leaf and leaf sheath, while absorbing corn juice, while excreting a large amount of honeydew, covering the honeydew on the leaf surface affects photosynthesis and is easy to cause mold parasitism. The growth of the injured plants was weak, the growth was poor, and the yield decreased.

Second, what drugs are used to control corn aphids?

1. Chemical control

(1) seed dressing with chemicals

Coating with 70% thiazine seed coating agent or seed dressing with 10% imidacloprid wettable powder has a better control effect on aphids at seedling stage.

(2) use granules

In the heart and leaf stage of corn, before the occurrence of aphids, 3% phoxim granule 1.5kg / mu or 15% chlorpyrifos granule 300g / mu, mixed with fine sandy soil according to the ratio of 1 ∶ / 30 / 40, was used to control corn borer.

(3) spray prevention and control

Seedling stage and early heading stage are the key periods for the control of corn aphids. If more aphids are found, spray such as 1000 times of imidacloprid wettable powder, 2000 times of cypermethrin EC, 2500 times of 2.5% cypermethrin or 2000 times of aldicarb and 6000 times of thiazine water dispersant are selected.

2. Agricultural prevention and control

In addition to the use of chemical control, the cultivation method of interplanting corn with wheat ridge is 10 times earlier than that of corn sown after wheat, which can avoid the peak period of aphid reproduction and reduce the damage. It can also timely field weeds to ensure the ventilation of the planting site. In addition, when planting, it is best to plant it in a place with good light, so that the chance of infecting aphids will be reduced.

3. Prevention and control of natural enemies

There are many natural enemies of aphids, including ladybugs, lacewings, aphid flies and parasitic wasps, which have a strong inhibitory effect on aphids. Try to apply as few broad-spectrum pesticides as possible, avoid applying pesticides during the peak period of natural enemy activities, and artificially raise and release aphids under certain conditions.

Generally speaking, although aphids are small, their harm should not be underestimated. In the process of planting, early detection and early control should be achieved.