Control method of corn thrips

Thrips are the general name of Thysanoptera of Insecta. The thrips that harm corn in China are mainly corn yellow thrips, grain thrips and rice tube thrips, all of which belong to Thysanoptera, the first two belong to thrips, and rice tube thrips belong to thrips. There are two generations of parthenogenesis on corn, mainly caused by adults eating corn. Let's take a look at the control methods of corn thrips.

Hazard characteristics

Thrips are mainly harmful in the heart leaves of corn, and release mucus, so that the heart leaves can not expand. With the growth of corn, the heart leaves of corn form a "whip". If measures are not taken in time, the yield will be reduced, or even the harvest will be eliminated. The adults move slowly and often do harm on the opposite side, resulting in discontinuous silver-white food lines accompanied by insect feces stains, and the corresponding parts of the leaves show yellow spots. Adults lay eggs in the mesophyll of the feeding place, and needle-tip-sized white spots can be seen in light perspective. The damage is mostly concentrated in the second to fourth or second to sixth leaves from the bottom up, and rarely turns to the new mouth even after a new period of time.

Occurrence regularity

In spring, yellow thrips first propagated on crops such as wheat, and then gradually transferred to spring corn fungus. Because of the large area of wheat, the insect source of spring corn and middle stubble corn mainly came from wheat. Generally from the end of May to the beginning of June, there is a nymph peak in wheat and spring corn, another adult peak in wheat, spring corn and middle stubble corn in June, another nymph peak in late June, and another adult peak in spring corn, middle stubble corn and summer corn in early July. Therefore, with the emergence of these peaks, timely measures should be taken according to the situation of insect pests.

Occurrence characteristics

Thrips prefer dry conditions and occur frequently in low-lying, windy and dry corn fields, and the intercropping of maize in wheat plants often suffers heavily. The rainfall from May to July in a year has a great influence on the occurrence degree of thrips, and drought and less rain is beneficial to the occurrence of thrips. Generally speaking, the number of occurrence on corn is spring corn > middle crop corn > summer corn. Although the number of insects per plant of interplanting corn in the middle crop was less than that of spring corn, the damage was more serious, especially under the condition of lack of water and fertilizer.

Prevention and cure method

The main results are as follows: 1. When fixing the seedlings of corn, pay attention to pulling out the insect seedlings and take them out of the field to rett fertilizer, which can reduce the spread of thrips. The hardened part of the leaf tip was removed manually to restore the growth of the new leaves. Timely irrigation and fertilization and strengthening management can promote the early development and rapid growth of maize seedlings and effectively reduce the damage of thrips.

2. At the initial stage of the occurrence of corn thrips, 10% imidacloprid wettable powder 1500 times, or 20% imidacloprid soluble solution 3000 times, or 26% chlorofluoroacetamiprid water dispersible granules 5000 times, or 3% acetamiprid 1500 times, or 10% cypermethrin EC 2500 times, or 2.5% imidacloprid 2000 times 3000 times, or 20% imidacloprid solvents 3000 times.