How to prevent and cure thrips with green onions?

Green onion thrips supplement tobacco thrips, cotton thrips and so on. In vegetable fields, they are mainly harmful to onions, leeks, garlic, cucumbers, eggplants and fruits. They are mainly distributed in Northeast China, Beijing, Hebei, Zhejiang, Jiangsu, Guizhou, Guangdong, Guangxi, Hainan, Taiwan, Shaanxi, Ningxia, * *, Xizang, Inner Mongolia and other provinces and regions. Let's take a look at how to prevent and control thrips.

Harmful symptoms of thrips with scallions

Thrips with onions damage the heart leaves, buds and young leaves of the above-mentioned hosts with adults and nymphs. Onions have their own insect activity and feeding throughout the growing period, resulting in the formation of silver-white stripes on the leaves after the onions are harmed, and the serious leaf distortion turns yellow and wilt, which seriously affects the quality and yield of onions. Green onions have a habit of eating raw food in the north, because the thrips are seriously damaged in recent years. As a result, the leaves are so scarred that they can no longer be eaten raw.

Occurrence regularity of thrips with scallions

Spring onion thrips occur for 8 to 10 generations a year in North China, mainly as adults overwintering in the leaf sheaths of onions, onions and garlic, in soil crevices or in withered leaf weeds, and stings when onions and garlic turn green. Adults are active, can be spread by the wind, afraid of strong light, feed mainly in the morning and evening, mostly in the back shade and leaf axilla feeding damage, can carry out parthenogenesis, eggs scattered in the host stem, leaf tissue. The nymphs are not very active and are mostly concentrated at the base of the leaves. After maturing, the 2nd instar nymph drills into the soil, molts into the pre-pupa and pseudo-pupa stage, and finally Eclosion into an adult. the days experienced by the first generation of thrips are 20-35 days, which will be prolonged when the temperature is low. The optimum conditions for its occurrence on onions are 23: 28 ℃ and 40: 70% relative humidity. High temperature, high humidity and storm can inhibit its occurrence.

Control measures of thrips with scallions

The main measures to control thrips with onions are to clean the countryside, remove weeds and residual leaves from onions and garlic fields and their surrounding areas in early spring, burn them centrally, and eliminate the source of overwintering insects. At the same time, fertilizer and water management should be strengthened, especially when the weather is dry, attention should be paid to watering to promote plant growth and destroy the ecological environment conducive to the occurrence of onion thrips.

Chemical control of thrips with scallions

The chemical control of spring onion thrips can be controlled by spraying 3% acetamiprid EC 2000 times, 10% imidacloprid wettable powder 1500 times, 4.5% cypermethrin 1000 times, 99% mineral oil 1000 times and so on. As the green onion leaves are relatively smooth, foliar spreading agent or neutral detergent can be added during spraying to increase adhesion and improve spraying effect.