How do plant aphids come into being (on the causes and control of crop aphids)

The occurrence of aphids may be caused by climatic factors, or by the decrease in the number of natural enemies of aphids. Aphids have strong reproductive ability, and can reproduce 10 ~ 30 generations a year, with prominent overlapping generations. Moreover, aphids can reproduce early, and female aphids can be pregnant and have children as soon as they are born.

What is an aphid?

Aphids are also called drilling insects, early insects, honey insects, ant insects and so on. Although their bodies are small, they can do great harm to plants.

Among them, except the gallnut aphid, which is beneficial, the others can be said to be destructive pests.

Aphids stab plant tissues with needle-like mouthparts, suck plant juice, and make injured plant leaves curl and wither, and even die in severe cases.

Causes of aphid production

1, the weather causes the occurrence of aphids.

Higher temperature, less precipitation and lower relative humidity are very beneficial to the occurrence and reproduction of aphids, among which the optimum temperature for aphids is 24-28℃ and the optimum relative humidity is 50-85%.

Usually aphids breed once every 3-5 days, and one aphid can breed 50-70, which is difficult to control.

2. Seasonal coefficient

The main activity time of aphids is from mid-April to late September, and some adults can fly. Sometimes it will spread with people, and some will spread with the wind. As long as potted plants are suitable for aphids to grow, they will reproduce soon.

3. The decrease in the number of natural enemies leads to the occurrence of aphids.

In recent years, due to a large number of pesticides sprayed in agricultural production, the number of planktonic insects and natural enemies has decreased, and the spread of aphids can not be controlled, which is the main factor leading to aphids.

Step 4 color

The ability of aphids to recognize colors is different from that of human eyes. Aphids have a positive tropism to yellow light and a negative tropism to silver-gray light.

How to control crop aphids

1, artificial control

We can kill or wash away a large number of aphids with high-pressure water spray. In case of spring drought, the opportunity of water replenishment can be used to control the population density and reduce the occurrence of aphids. But it is best to spray water continuously in a season to achieve the ideal effect.

2. Biological control

Pay attention to the protection and utilization of natural enemies of aphids. The natural enemies of aphids are mainly ladybugs, harmonia axyridis, Chrysopa sinica, Syrphidae and so on.

We can use the artificial migration of natural enemies such as ladybugs and syrphids, and we can also control them effectively.

3. Chemical control

There are many chemical control methods for aphids, and the proportion of drugs used varies from place to place. Some are injected or buried in the trunk and roots of trees for prevention and control, mainly spraying drugs on the crown, and the effect is also remarkable.