Carrot pests: control methods of cabbage worm, red stripe bug, microtube aphid, tobacco green worm and small leaf roll moth

The planting process of carrots is often attacked by insect pests, such as cabbage worm, red stripe bug, microtube aphid, tobacco green worm, small leaf moth and so on, which seriously affect the yield and quality of carrots and need to be controlled in time. The main pest control methods of carrots are introduced as follows:

1. Carrot striped bug

It is mainly harmful to Umbelliferae plants such as carrots and fennel and vegetables such as radish, cabbage, onion and onion, as well as oak, elm, yellow pineapple and so on. Adults and nymphs often live on the leaves, buds and young pods of the host plant to absorb juice, and the plant growth is weak. if the seed vegetable is damaged, the seed pod will be deformed and the seed yield will be reduced.

Prevention and control methods:

To master the peak incubation period of local eggs, 2.5% deltamethrin EC 2000 times, 1.8% avermectin EC 2000 times, 90% crystal trichlorfon 1000-1500 times, 50% phoxim EC 1000-1500 times, 50% malathion EC 1000-1500 times, spray once in 5-7 days at the peak, and control 2-3 times in a row. Stop taking medicine 7 days before harvest.

Picture: red striped bug

2. Carrot microtubule aphid

Adult and nymph aphids mainly damage the tender shoots of Umbelliferae plants, make the young leaves curl and reduce the yield and quality. Celery and fennel seedlings curled up after being killed. Carrot seedlings often turn yellow after being damaged.

Prevention and control methods:

a. In early spring, pesticide can be applied to overwintering celery or other nearby vegetables with more overwintering aphids to prevent winged aphids from migrating and spreading.

b. For example, more aphids on celery can be sprayed with 2000 times of aldicarb wettable powder or 1500 times of imidacloprid wettable powder, 1000 times of phoxim emulsion, 1000 times of 50% malathion emulsion, 600 times of 2.5% ivy concentrate emulsion, and 2000 times of 20% permethrin 3000 times. Stop using drugs 7 days before harvest

c. When aphids occur in celery in the shed, aerosol No. 4 can be used, 350 grams per 667 square meters, labor-saving and effective.

3. Carrot tobacco green worm

Larvae eat buds, flowers and fruits, as well as tender stems, leaves and buds. After feeding, the pest forms many holes and holes, leaving only leaf veins in serious cases. The main reason for yield loss is fruit decay caused by fruit decay and a large number of fruit drop.

Prevention and control methods:

a. Field treatment after harvest. After harvest, the fields should be cleaned and the land should be ploughed; before freezing, the winter irrigation of vegetable fields, or deep ploughing in winter and early spring, or rotation with non-Solanaceae crops should be done in order to eliminate the overwintering pupae and plant residues of cotton bollworm and reduce the number of insect sources in the coming year.

b. Use lights to trap and kill. Field installation of insecticidal lights, black lights, can trap and kill a large number of adults.

c. In order to control cotton bollworm, we should select the first generation, severely treat the second and third generation, and pay attention to the fourth generation. And should be mastered in the peak spawning period, surprise spraying once within 3 days, when half of the eggs become black, the spraying effect is the best. Before the third instar larvae of Helicoverpa armigera were sprayed every 7 days from the beginning of egg hatching to the third instar larvae. The medicament can be selected with high efficiency, low toxicity and low residue pesticide, generally using 300ml / mu of Bacillus thuringiensis, 1000-1500 times of 5% flurosemide EC, 2000 times of 10% imidacloprid wettable powder, or 25% cyanoamyl. Phoxim EC 1500 times liquid spray. The best time of application is before 09:30 in the morning and after 04:00 in the afternoon.

4. Carrot leaf moth

Generally, the damage of summer sowing carrots is more serious, there are five generations a year, and the occurrence period of adults is from April to September. A single egg is scattered on the ground. The amount of occurrence varies greatly from year to year, generally large in years with high temperature from July to August, but not in cold areas.

Prevention and control methods:

Root irrigation treatments such as 48% Lexben EC 500 times 800 times, 50% phoxim 1000 times, 40% dimethoate EC 1000 times, 90% crystal trichlorfon 1000 times and so on.

5. Green beetle of carrot

From November to March of the following year (the peak planting period of cruciferous vegetables), the number of occurrence was the most, and the harm was the most serious. Adults sleep during the day and go out at night, hide in the shade of plants in the field during the day, and fly short distances between plants when disturbed. After mating, most eggs lay near the leaf veins, producing per unit or gathering several grains, with an average of about 250 eggs per female. The egg period is 3 to 11 days. After hatching, the larvae latent feed on the mesophyll, and most of them feed on the back of the leaves after the 2nd instar, leaving a translucent upper epidermis. After the 3rd instar, the food intake increases greatly, and the leaves can be bitten into holes. In serious cases, only veins are left, which makes the vegetables lose their commercial value. The larvae are very active, and when disturbed, they quickly twist backward or spin and fall, but wait for a moment and then return to the leaves along the route to continue feeding. The larvae were 4th instar, and the development period was 12-27 days. Most of the mature larvae pupate near the veins on the back of the leaves, and some pupate on the withered leaves. The pupa stage is 4-8 days. The life span of adults is 11-28 days. Adults have strong phototaxis and need to suck nectar to supplement nutrition.

Prevention and control methods:

a. Agricultural control: rational distribution to avoid annual continuous cropping of cruciferous vegetables is a preventive measure to restrain the occurrence of Plutella xylostella. Intercropping Solanaceae crops has the effect of repellent and oviposition. The number of insect sources can be reduced by removing the residual leaves in time after vegetable harvest.

b. Physical control: in the peak period of adult occurrence, setting a black light for every 10 mu of vegetable field can trap and kill a large number of Plutella xylostella adults.

c. Biological control: the protective and assisted release of Plutella xylostella has a significant effect on reducing the natural population of Plutella xylostella. Apply 500-700 times of B. thuringiensis preparation B.T emulsion or granulosis virus of Pseudomonas aeruginosa 6, and trap male moths with female external hormone "cis-11-hexadecenyl acetate" or "cis-11-hexadecenal" The application of 20% diflubenzuron 500-1000 times solution, or 5% Yitaibao, Nongmont, Cardicol 2000 times solution has a good control effect on resistant diamondback moth, and the effect is longer, so it should be used as the main means to control Plutella xylostella.

d. Chemical control: 5% fipronil (fipronil) suspension or 10% (fipronil) suspension 2000-3000 times, 20% deltamethrin EC 3000-4000 times have better control effect.