What kind of pesticide does onion thrips use to kill

Thysanoptera thrips belong to Thysanoptera thrips, which mainly harms vegetables of Liliaceae such as onions and leeks, as well as Solanaceae, melons, cotton, tobacco and other crops. There are more than 30 species of host plants in 18 families, which are distributed all over the country. So, what kind of pesticide does spring onion thrips kill?

What pesticide does onion thrips use to kill?

Pesticides such as 99.1% trichlorfon EC, 5% fipronil suspension 2500 times, 40% chlorpyrifos EC 1000 times, 12% Mala, 6.3% awei ·high chlorine wettable powder 5000 times or 2.5% doxorubicin suspension 1000 times can be sprayed, spraying pesticides once every 10 days or so, and applying 2-3 times.

2. Occurrence regularity of onion thrips

Onion thrips vary from 6 to 10 generations a year in the north. The adults can begin to move when the daily average temperature reaches 4 ℃, feed actively when the daily average temperature is more than 10 ℃, and lay eggs when the ten-day average temperature rises to more than 12.5 ℃. When the ten-day average temperature rises to 16.6-19.6 ℃, it propagates rapidly and the population increases rapidly. The nymph could not survive when the temperature exceeded 38 ℃. Although the nymph developed rapidly when the temperature was close to 38 ℃, the mortality rate was higher. When the relative humidity reached 100%, the nymph could not survive at 31 ℃, and the development could be completed when the humidity dropped to 75%. The most suitable conditions for the occurrence of onion thrips are 20-28 ℃ and 40% relative humidity, 70% relative humidity. A long period of drought in spring is a sign of great occurrence.

Adults and nymphs overwintered in the leaf sheaths of unharvested onions, onions and garlic, and a few overwintered in the remnants of weeds and green fields covered with grass and dung in winter or in the soil near the damage. It was active on crops and weeds in early spring from March to April, and moved to green onion fields or cotton fields from late April to early May, and the peak period was from mid-May to mid-June. July to August is the high temperature and rainy season, onion thrips because the humidity is too high, the population density will naturally decrease. In addition, cotton fields with more weeds, loose soil, intercropping or continuous cropping of spring onion and cotton and early sowing cotton fields are generally more serious near or near the overwintering place.

Third, the harm of onion thrips to crops

Both adults and nymphs suck plant juice with file-sucking mouthparts. Among the vegetables, green onions suffered the most. After the onion leaves were killed, many fine and long gray or yellow spots were formed. In severe cases, the leaves lose swelling pressure and sag, and even twist and turn yellow. when moderate occurs, it can cause 30% loss of green onions, and when serious occurs, it can cause 50% loss, affecting the yield and quality of green onions. In the cotton field, the cotyledons, tender true leaves and tips of cotton seedlings were mainly harmed, and the leaflets were damaged with silver-white patches, and when the cotyledons were serious, the cotyledons withered and shrunk. After the real leaf was killed, yellow plaques occurred, and in severe cases, the scorch was broken. Before the true leaves are produced, the top becomes black and withered and falls off, and the cotyledons become hypertrophic and become "male cotton" (that is, headless cotton) that cannot grow seedlings, and die soon; if the true leaves are damaged, they will form "multi-headed cotton", branches and leaves will grow in clusters, affecting the plant type in the later stage, resulting in reduced yield; flowers and buds can also fall off when they are seriously damaged.

Spring onion thrips do great harm to green onions and other crops, mainly for control. They can remove weeds and litter in the field and around them in early spring, and bring them out of the field for centralized destruction to reduce the number of insect population. Watering and weeding frequently in dry weather can reduce the harm.