What are the hazards of wheat aphids, how to prevent wheat aphids?

What are the hazards of wheat aphids, how to prevent wheat aphids? Wheat aphids are one of the important pests of wheat in China, and occur to varying degrees every year, but the control effects appearing in recent years are poor. This article introduces in detail the morphological characteristics, occurrence regularity, damage and prevention methods of wheat aphids, for your reference.

What are the hazards of wheat aphids, how to prevent wheat aphids? Wheat aphids not only absorb plant juice, affect crop development, but also spread a variety of viral diseases, which can cause severe wheat yield reduction.

What are the hazards of wheat aphids, how to prevent wheat aphids?

1. Morphological characteristics of wheat aphids

1.1 Mai long tube 蚜 wingless parthenogenetic body length 3.1mm, width 1.4mm, long 卯 shape, grass green to orange red, sometimes the head is red or brown, there are inconspicuous gray-green to gray black spots on both sides of the abdomen . The tentacles are black, and in section 3 there are 8-12 sense circles lined up. Sections 6-8 of the abdomen and transverse masks of the abdomen mask, no tumor.喙 Large, black, longer than the midfoot base. The abdominal tube is long cylindrical, black, 1/4 of the length of the body, and has a dozen lines of netting at the end. The winged parthenogen is 3.0mm long, oval and green. I can't reach the base of the foot. The abdominal tube is long cylindrical, black, with 15-16 rows of cross-webs at the ends, and a long cone-shaped tail with 8-9 hairs. If the carcass is green, sometimes pink, compound eyes are red, and the body is shorter.

1.2 Mai Erqi body is round, 2.0mm long and 1.0mm wide. Light green, dark green in the back line. The antennae are 6 knots, black, but the base section of the 3rd section and the 1st and 2nd sections are light-colored, and the length is 2/3 of the body length. It is light, but the third and end sections are grayish black, the length is longer than the midfoot base, and the end section is short. The abdominal tube is long cylindrical, light green and black at the top. The middle tumor is slightly elevated, and the frontal tumor is higher than the middle tumor. The middle chest and abdomen have a short handle. Winged parthenogen: The body is long and oval, 1.8 mm long and 0.73 mm wide. Head, chest black, light belly. The antennae black is 6 knots and the total length is more than 1/2 of its body length. The third section of the tentacles has 4-10 small circular secondary sense circles arranged in a row. The mid-wing midrib is bifurcated. Other features are similar to the wingless type.

1.3 Hegu 缢 缢 蚜 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤 孤The antennae are 6 knots, black, but the bases of the 1st, 2nd, and 3rd sections are lightly colored, and the length exceeds 1/2 of the body length. The chest and abdomen are sessile. The middle tumor is raised. It is thick and thick, and is longer than the base of the midfoot. It is twice as long as the width. The abdominal tube is grayish black, with a black top, a long cylindrical shape, and a sharp edge. There are often pale brown or rust stains around the base of the abdominal tube. The tail piece and tail plate are grayish brown. The winged parthenocarp has a long scorpion shape with a body length of 2.1mill and a width of 1.1mill. Head, chest black, abdomen dark green, with black markings. The third section of the tentacles has 19-28 rounded secondary sense circles and 2-7 in the fourth section. Sections 2-4 of the abdomen have large green spots, and the posterior canal is large, extending forward around the abdominal tube. Sections 7 and 8 have a mid-belt in the abdomen. The abdominal tube is black. Other features are similar to the wingless type. If the body is lavender, it is white powder, the compound eyes are brown, and the tentacles and feet are light.

What are the hazards of wheat aphids, how to prevent wheat aphids?

2. The occurrence of wheat aphids

Wheat aphids can occur for 10-30 generations in one year. In the south of the Yellow River, the wheat long tube is formed by the wingless tires and the nymphs are overwintering around the rhizosphere or under the soil. There is no obvious dormancy in the south of the Yangtze River. Winters below 10-2 °C cannot be wintered. . Every spring, with the rise of temperature, the wintering long tube mites produce a large number of winged mites, which migrate with the airflow into the northern winter wheat area for breeding. 1 In the north, the wheat birch is overwintered on the dead leaves, soil joints and weeds or under the soil in the north of the wheat. In the south of the Huaihe River, the wintering of the medlar and the nymphs in the wheat seedlings and soil seams, no obvious dormancy. When you are warm, you can still climb to the foliage to feed. 2 In the north of the Yangtze River, the cereals are overwintered in the bark seams and buds of apples, peaches, etc., and the wheat is seriously damaged in the first half of May. After harvesting, the large number of eggs are moved to corn and sorghum. . 3 The long tube stalk of the wheat grows up with the growth of the upper part of the plant, and it is most like to suck on the young ear, so it is also called "scarlet". The wheat mites are distributed in the lower part, which is harmful on the back of the leaves. The environment of the glutinous rice stalks is more harmful to the back of the wheat leaves, and even on the leaf sheath at the base of the wheat stems.

The occurrence of wheat aphids is closely related to temperature and humidity. When the temperature is lower than 6 °C or higher than 28 °C, the worm's mouth is significantly decreased, and when the humidity is lower than 40%, the occurrence of mites is also significantly inhibited.

What are the hazards of wheat aphids, how to prevent wheat aphids?

3. Main hazards of wheat aphids

3.1 Absorption of nutrients Wheat aphids use adult nymphs and nymphs to suck the sap of stems and leaves of wheat plants to harm wheat. The damage of wheat seedlings can cause yellowing of leaves, affecting growth, and even dead of yellow; damage from jointing to booting stage affects heading; yellow spots appear in the late part of the damage, wheat leaves gradually yellow, wheat grains are not full, and wheat ears are dry when severe White, can not be strong, and even the whole plant is dead, seriously affecting the yield.

3.2 Affecting photosynthesis When wheat aphids occur in large numbers, the honeydew that is released from the aphids is applied to the leaves and tender ears of wheat, which seriously affects photosynthesis and causes wheat to reduce production.

3.3 Poisoned wheat Aphids can also spread wheat yellow dwarf disease, yellowing wheat leaves, short plants, affecting yield, resulting in greater losses than feeding nutrients.

What are the hazards of wheat aphids, how to prevent wheat aphids?

4. Wheat locust control method

4.1 Agricultural control and rational adjustment of crop layout, such as spring wheat area does not grow winter wheat, winter wheat area to reduce sorghum planting area. Adjust the sowing time, avoid the peak period of aphid at the earing stage, and make the wheat heading maturity period advance or postpone accordingly to reduce the damage. Early-maturing varieties are selected. Early-maturing varieties have earlier growth and development. When the wheat is warmed, the growth period of wheat is late, which can avoid or reduce the damage of aphids.

After the wheat harvest, the shallow ploughing and hoeing in combination with deep ploughing can eliminate the wheat seedlings and various grass weeds in the wheat field and control the amount of summer glutinous rice. Winter irrigation and early spring flooding can be carried out in places where conditions permit.

4.2 Protecting the natural enemies of natural enemies, there are many natural enemies that control the wheat stubble. There are various ladybugs, grasshoppers, cockroaches and flower buds. The parasitic natural enemies have a variety of cockroaches. These natural enemies have a large number of wheat fields. When the ratio of the number of enemies and the number of locusts reaches 1:150, the natural enemies can control the wheat stalks below the control indicators, without the need for medication control. Therefore, the wheat field should pay attention to scientific medicine and use selective agents for the safety of natural enemies.

4.3 Chemical control Spring is a season in which aphids are suitable for growth and damage, and are dominated by wheat long tube. Temperature and humidity play a leading role in the growth and decline of wheat bran. In general, the temperature is between 15 and 25 ° C, and the relative humidity of 40% to 80% is the condition under which the wheat bran occurs. From the perspective of wheat growth and development, the amount of alfalfa increased slowly before heading, and the amount of alfalfa increased sharply after heading. The amount of alfalfa reached the highest peak during the period from filling to maturity, and the yield loss was the most serious during grain filling. Therefore, we should grasp the prevention and control of wheat stubble in the late stage of wheat flowering and early filling. The drug can be selected with 10% imidacloprid wettable powder 2000 times liquid 25% fast killing spirit milk l000 times liquid 3% acetamiprid emulsifiable oil l500 times liquid 2.5% Baode emulsifiable oil 2500 times liquid 5% high efficiency big chen WP 1000 times liquid and 50% anti-Converse WP 4000 times solution. Long-term single use of drugs is easy to make wheat bran resistant. Therefore, it is necessary to arrange and rotate medicines reasonably.

What are the hazards of wheat aphids, how to prevent wheat aphids?

5. Mistakes in the control of wheat aphids

5.1 fallacy best prevention period

At present, the control of wheat aphids is early or too late. Seeing the insects is the application of drugs, the number of spraying is correspondingly increased, resulting in high cost of prevention and control, and at the same time, the resistance of aphids is enhanced, and the difficulty of prevention and treatment is further increased. Too late to control, mites have caused certain damage to wheat. The density of mites is too large. If the application cannot be applied evenly, the damage of the mites cannot be effectively controlled.

5.2 improper use of drugs

Most farmers lack specificity when selecting pesticides, and mistakenly believe that pesticides with high toxicity have relatively good insecticidal effects. Highly toxic and poisonous pesticides are generally broad-spectrum insecticides. While effectively controlling target pests. It will also harm natural enemies and some beneficial biological species such as bees, which will destroy the balance of the ecosystem of the entire farmland and cause pollution to humans, animals, water bodies and ecological environment. At the same time, the high-toxic pesticides have a short duration of action and high residuals. The application of pesticides near the harvest period results in excessive pesticide residues, which is not conducive to the healthy life of the people. In addition, most farmers lack some conventional knowledge to distinguish between true and false pesticides, such as pesticides, etc. If the fake drugs are inadvertently applied, the cost of prevention and control can be increased, and the purpose of preventing and treating diseases and pests can not be achieved, which brings great harm to production.

5.3 Unreasonable application techniques

Some farmers abuse pesticides, and the selection of varieties is relatively simple, frequent application, resulting in a significant increase in the resistance of the insect, and enhanced resistance. Only by further increasing the amount of drug used and increasing the number of drugs used, farmers will further increase the resistance of the insects and increase the cost of prevention. Secondly, the amount of water is generally less and the application is not uniform. Especially in the middle and late stages of wheat, the density of the field is large, and it is difficult to touch the aphids at the back of the leaves and the stalks. When the weather is suitable, it is easy to cause the mites to re-smash. Therefore, it is often necessary to spray 2-3 times during the growth period of wheat. Difficulties in prevention and high cost are the biggest problems in the control of wheat aphids.

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