What medicine does the common crop corn, tomato, cotton bollworm appear to hit? How to treat it?

Corn, tomato and cotton are common crops, which are also prone to diseases during their growth, resulting in crop yield reduction and even death. So if cotton bollworms show up, what's the poison? How?

What is cotton bollworm? How to identify?

1. Cotton bollworm belongs to Lepidoptera and Noctuidae. It harms many crops, in addition to cotton, but also harm corn, tomatoes, flax, sunflower, peas, peppers and other crops as well as a variety of weeds. Cotton bollworm alias a lot of damage to corn called corn ear worm. In recent years, cotton bollworm damage to maize has increased in some areas where cultivation reform and multiple cropping area have been expanded, especially in southern Liaoning, Yangtze River Basin and some areas of Xinjiang.

2. Adult: grayish brown medium-sized moth, body length 15~20mm, wing spread 31~40mm, compound eye spherical, green (closely related species tobacco green compound eye black). The female moth is reddish brown to grayish brown, the male moth is greenish gray, the front and rear wings of the cotton bollworm can be used as the model of the adult of the family Noctuidae, and its front wings have dark gray broad bands outside the outer horizontal lines, and there are 7 small white spots on the bands, kidney stripes, and dark brown ring stripes. hind wing gray, along the outer edge of a black-brown broad band, broad band center has 2 connected white spots. There is a crescent-shaped brown spot on the front edge of the hind wing.

Egg: Hemispherical, 0.52mm high, 0.46mm, slightly raised at the top; the surface is covered with vertical and horizontal stripes, 1~2 longitudinal stripes seen from the top, 2 longitudinal stripes in the middle, 1~2 short stripes and 2~3 branches, so there are 26~29 longitudinal stripes seen from the middle.

Larvae: 6th instar, sometimes 5th instar (feeding on pea seedlings, sunflower disk), mature 6th instar about 40~ 50mm long, head yellow brown with indistinct stripes, larvae body color is variable, divided into 4 types: 1) body color light red, dorsal line, subdorsal line brown, stigmatic line white, hair process black. 2) yellow and white body color, dorsal line, light green subdorsal line, white stigmatic line, hair process and body color the same. 3) light green body color, dorsal line, subdorsal line is not obvious, valve line is white, hair process and body color are the same. 4) dark green body color, dorsal line, subdorsal line is not obvious, valve pale yellow. There is a brown vertical band above the spiracles, which is formed by sharp microspines arranged (the microspines of tobacco green insects are blunt and round, not arranged in line). The 1st, 2nd and 5th segments of larva abdomen each have 2 hair processes especially obvious.

Pupa: 17~20mm long, spindle shape, reddish brown to dark brown, abdomen end has a pair of hip thorn, thorn base is separated. The stigmata are larger, the peripore pieces are cylindrical and higher, the dots of the 5th to 7th nodes on the abdomen are semicircular, thicker and sparse (the stomata of tobacco budworm are small, the base of thorns are closed, the peripore pieces are not high, the dots of the 5th to 7th nodes are fine, some are semicircular, and some are round). 5~15cm into the soil and pupate, covered with soil cocoons.

Corn, tomato, cotton bollworm appear what medicine to hit? How?

Corn:

1. Physical control

Poplar branches lure moths: adult moth stage, should be carried out in large areas, especially in cotton fields, can eliminate a large number of adults, to reduce the local insect source role is greater.

High pressure mercury lamp and frequency-vibrating lamp were suitable for trapping cotton bollworm, which had the characteristics of killing large numbers of cotton bollworm and killing small natural enemies.

2. Biological control

Release Trichogramma: release bees twice during the peak spawning period of cotton bollworm, 300,000 bees per hectare, divide 60 bee release points (20,000 bees per mu, 4 bee release points), put the Trichogramma cards that can emerge the next day into open paper bags and hang them in the middle and lower parts of plants.

3. Chemical control

2.5% cypermethrin EC 2000 times solution, 5% beta-cypermethrin EC 1500 times solution and other chemical pesticides were sprayed on the leaves before the third instar. Insecticidal granules are sown in corn leaves in late June. The pesticide and application method are the same as corn borer.

4. Agricultural control

Autumn tillage and winter irrigation reduce the base number of overwintering insects. Optimize crop layout, avoid migration and reproduction of cotton bollworm in adjacent crops. Plant corn induction belt at the edge of cotton field and ditch ridge, select early-maturing corn varieties, about 2200 plants per 667 square meters. By utilizing the habit that cotton bollworm adults like to inhabit and lay eggs in corn bell mouth, special personnel beat heart leaves every morning to eliminate adults and reduce insect source.

Tomatoes:

Cultivate the land before winter and irrigate the flooded land to reduce the source of overwintering insects. According to the forecast of insect situation, in the peak spawning period of cotton bollworm, combined with pruning, the eggs were removed and burned.

When the number of eggs per hundred plants reaches 20-30, the drug should be started. If the number of larvae per hundred plants exceeds 5, the drug should be continued. The drug is usually started when the fruit begins to expand.

Cotton:

1, bifenthrin EC 3000-5000 times;

2, methylamino abamectin benzoate microemulsion 7500-15000 times;

3. 52.25% Cyanchlorpyrifos EC 1500-2000 times;

4. 28% Cyanide·Phoxim EC 1000-1500 times;

5.48% Chlorpyrifos EC 500-800 times;

6, 2.5% beta-cyhalothrin EC 1500-2000 times;

7. 40% Dibai·Chlorpyrifos EC 1000-1200 times.

Pesticide spraying site of cotton bollworm

Cotton bollworm eggs, generally produced in the top of cotton plants, fruit branches on the top of the tender leaves, buds and bracts on the leaf. Spray should focus on the top of cotton plants and fruit branches of tender tips, buds and bracts.

Pesticide spraying time:

The hatching rule of cotton bollworm is white in the first day, yellow in the second day, dark in the third day and hatching in the fourth day. On the second day after hatching, it will harm the growth point, and on the fourth day, it will move and harm the young bud. Cotton bollworm was active from 8:00 to 11:00 a.m. and after 4:00 p.m., but rarely active during high temperature period at noon. The optimum period for control was from 8:00 a.m. to 11:00 p.m. and after 4:00 p.m. Avoid high temperature when the application, high temperature when the application is easy to volatilize decomposition, not only the operator is easy to poison, but also poor efficacy.

Alternate use of pesticides:

Do not use one pesticide in succession to prevent cotton bollworm resistance.

Pesticide concentration:

Pesticide concentration shall be prepared according to the instructions, and shall not be increased or decreased arbitrarily. Increasing the concentration will cause injury to cotton plants, decreasing the concentration will reduce the efficacy.

Dosage of pesticide solution:

If the dosage of liquid medicine is small and the cotton plants are sprayed unevenly, the effect of insect control will be poor. When controlling the second generation cotton bollworm, the amount of liquid medicine used per mu should not be less than 40 kg, and when controlling the third and fourth generation cotton bollworm, the amount of liquid medicine used per mu should be 80~100 kg. Cotton plants all parts of the drug evenly, the effect is good.