What are the symptoms of being harmed by cabbage worms?

Only the veins remain, and the whole leaf becomes reticulated. Only leaf veins remain, and cabbage insects can eat the whole leaf after 3 instars; The whole leaf becomes reticulated, and the diamondback moth is very erosive.

Vegetables that have been damaged by cabbage insects usually wilt, the leaves turn yellow or even black, and cavities and white thread-like eggs appear on the leaves. The harm to vegetables is very great.

Cabbage worm is a common cabbage pest. The cabbage worm eats on the leaves of cabbage mustard greens, resulting in a striated leaf loss. As a result, crop yields are reduced.

1. There are few pesticides on insects and vegetables, which has no effect on the human body;

2. The insects and vegetables can be cleaned to remove the insects and accompanying residues. When washing the greens, soak the greens first, put some salt in the water to soak the greens, and after a while, if there are insects, they will come out, so that the greens will not have insects;

3. Insects are not poisonous and can be eaten after high temperatures;

4. Green vegetables contain a variety of nutrients and are rich in vitamin C. The oil content of green vegetable seeds is 35 50%, and its rapeseed oil is rich in fatty acids and vitamins, with high nutritional value, which is not only a good edible vegetable oil, but also has a wide range of uses in industry;

5. Green vegetables are used for pickling pickles, pickled cabbage fish, famous all over the world, and can also be dried as moldy dried vegetables. The stewed soup clears the internal organs, and the damp heat is dry. Stir-fried vegetables are stir-fried with dried chili peppers, which are crisp and nutritious, economical and commonly eaten;

6. When eating hot pot, green vegetables are also people's first choice, because people like to eat some special dishes and meat at the beginning of eating hot pot, and often need some light vegetables in the end, at this time, green vegetables will be people's best choice.

The cabbage insect is most afraid of its natural enemies: birds, praying mantises, Chinese leaping spiders, toons, Chinese microspiny blind bugs, hunting bugs, turtle ladybugs, heterochromatic ladybugs, butterfly pupae golden wasps, red-eyed bees and other natural enemies.

Precautions: Insecticides such as chlorpyramide and cypermethrin are generally used for control. Among them, chlorpyramide has a slow effect and needs to be sprayed mainly for prevention or in advance. In order to reduce pollution, plant-derived pesticides such as pyrethrin EC, pyrethrin EC, and azadirachtin EC can be used for control.

Because cruciferous vegetables eat leaves, high-efficiency and high-toxicity insecticides cannot be used, otherwise it is easy to cause food poisoning.

The prevention and control of cabbage insects is mainly prevention, and it is necessary to produce in the adult occurrence period, if the planting area is small, it is generally controlled by manual capture, which can avoid pesticide residues.

Vegetable insect hazard control methods: agricultural control, biological control, chemical control.

1. Agricultural prevention and control.

Rational layout, try to avoid cruciferous vegetables annual continuous cropping. Within a certain time and space, cut off its food source. After the cruciferous vegetables are harvested, the field residues are removed to eliminate the remaining larvae and pupae in the field.

In early spring, you can cover the mulch film to advance the planting period of cabbage in early spring and avoid the damage of the second generation of cabbage insects.

2. Biological control.

Protect and use the Rising Orange Reed Enemy. During the occurrence of a large number of natural enemies, care should be taken to minimize the use of chemicals, especially pesticides with broad spectrum and long residual effect. Release natural enemies such as butterfly pupae and red-eyed wasps.

Use BT emulsifiable concentrate spray, or rapeseed butterfly particulate virus and parasitic nematodes, etc.

3. Chemical control.

The chemical control of rapeseed butterflies should be based on the occurrence period and the established control indicators, comprehensive consideration of climate, natural enemies and the remaining period of vegetables, to determine the appropriate period of control. Generally, the commonly used agents are, 90% crystal trichlorfon 1000 1500 times liquid, or 50% dichlorvos emulsifiable concentrate 1000 times liquid spray and so on.

Introduction to cabbage worms

Vegetable butterflies, also known as cabbage butterflies, larvae, also known as cabbage insects, are the most widely distributed and most serious pests in China, and often fail to become disasters. There are as many as 35 known host plants in 9 families, and they are fond of cruciferous plants, especially cabbage, cauliflower, cabbage, and radish with thick leaves. In the absence of cruciferous plants, other host plants can also be eaten, such as Asteraceae, broccoliaceae, nasturtium, lily, comfrey, rhinoceraceae and other plants.

The larvae bite the host leaves, only eat the mesophyll before the 2nd instar, leaving a layer of transparent epidermis, and eat away at the leaf holes or missing nicks after the 3rd instar, and the leaves are all eaten up when the leaf is noisy, leaving only the coarse leaf veins and petioles, resulting in extinction, which is easy to cause the epidemic of cabbage soft rot. When the damage is serious at the seedling stage, the whole plant dies at the worst, and the core is affected at the lightest.

The above content refers to Encyclopedia - Vegetable Powder Butterfly.

Greens, also known as bok choy or green cabbage seedlings, are a very common vegetable. During the growth of green vegetables, they may be affected by various diseases. Here are some common greens diseases:

1.Blight: This is a disease caused by the fungus Rhizoctonia solidum, which mainly affects the roots and base of green vegetable seedlings. The disease is manifested by browning and wilting at the base, and in severe cases, the whole plant dies.

2.Downy mildew: caused by frosty mold fungus, mainly harming the leaves of green vegetables. The disease is characterized by the appearance of pale yellow to brown lesions on the leaves, and the appearance of a white mold layer on the later lesions.

3.Botrytis cinerea: Caused by the gray mold, it mainly damages the leaves, stems and flowers of greens. The disease is manifested by the appearance of water-stained lesions on the leaves, which gradually expand, and the whole leaf turns brown and wilts when it is severe.

4.Soft rot: Caused by soft rot bacteria, it mainly damages the stems and roots of green vegetables. The symptoms are water-stained soft rot on the stems and roots, foul-smelling, and the diseased parts are prone to ulceration.

5.Viral disease: Caused by a variety of viruses, it mainly affects the leaves of green vegetables. The symptoms of hunger are manifested in the appearance of greening, yellowing, deformity and other symptoms of leaves, which affect the yield and quality of vegetables.

The methods of prevention and control of green vegetable diseases include: selecting disease-resistant varieties, reasonable crop rotation, strengthening fertilizer and water management, timely removal of diseased plant residues, and the use of pesticides for prevention and prevention. When using pesticides, it is necessary to pay attention to the reasonable use of concentrations and methods to avoid affecting the environment and human health.

Vegetable.

The larvae of the cabbage worm bite the leaves of rapeseed, only eat the mesophyll before the 2nd instar, leaving a layer of transparent epidermis, and after the 3rd instar, the leaves appear holes or missing entries, and the leaves are all eaten up in severe cases, leaving only coarse leaf veins and petioles, resulting in extinction. When cabbage insects feed, they excrete fecal contamination while feeding. The larvae were instar 5 instar, mostly on the back of the leaf before the 3rd instar, and turned to foliar nibbling after the 3rd instar, and the feeding amount of the 4-5 instar larvae accounted for 97 of the whole larval stage.

Prevention and control methods: 1. Agricultural prevention and control. Clean the field, after rape harvest, remove the old leaves of the field in time, reduce the breeding place of the cabbage worm and eliminate some pupa.

2. Chemical control. Generally, about 1 week after the peak of eggs, that is, before the larval hatching period to the 3rd instar larvae, the following agents can be used:

1) 2 30-50 grams of insecticide and acaricide for vegetable dan, spray 50 kg of water or 750-1000 times of high-efficiency BT wettable powder, or 2500-3000 times of aveanzizo emulsifiable concentrate.

2) 10 5-10 ml of annihilation emulsifiable concentrate, 10 ml of 10 ml of depleted suspension agent, 5 kung fu pyrethrin emulsifiable concentrate and 5 lyflin emulsifiable concentrate 2000-3000 times or other pyrethroid emulsifiable concentrate spray to control the void.

3) 20 chlorpyramide No. 1 suspension agent and 25 chlorpyramide No. 3 suspension 1000 times liquid spray control. Prevention and control should pay attention to grasp the appropriate period of prevention and control, in the field egg period, larval orange hatching early spraying, according to the habit of cabbage insects, in the morning or evening on the back of the leaves of the plant evenly sprayed, can effectively prevent and control the harm of cabbage insects.