Vegetable worms only eat cruciferous vegetables, such as cabbage!
Lettuce contains the following components: erucic acid:
Cis-CH3 (CH2) 7ch = ch (CH2)11cooh.
Naming:
Cis-13- ene docosanoic acid
Question 2: Is it true that lettuce is worm-free? Why? Isoprene in lettuce has insect repellent effect.
Lettuce is extremely rich in nutrients, including antioxidants, beta carotene, vitamins B 1, B2, B6, vitamin C and vitamin E, and also rich in trace elements and dietary fiber, including calcium, phosphorus, potassium, sodium, magnesium and a small amount of copper, iron and zinc. Eating lettuce regularly can improve gastrointestinal blood circulation and promote the digestion and absorption of fat and protein. Lettuce can also protect the liver, promote bile formation, prevent cholestasis and effectively prevent gallstones and cholecystitis. In addition, lettuce can remove the garbage in the blood, which has the functions of blood disinfection and diuresis, and can also remove intestinal endotoxin and prevent constipation.
The latest research by scientists found that spherical lettuce contains a protocatechuic acid substance, which has obvious inhibitory effect on pancreatic cancer. In the past, protocatechuic acid was known to have certain inhibitory effects on tongue cancer, gastric cancer, liver cancer, colorectal cancer and bladder cancer. Now it is considered that it also has obvious inhibitory effect on pancreatic cancer.
Lettuce is a compositae vegetable, also known as leaf lettuce. Vegetable worms only eat cruciferous vegetables, such as cabbage! Lettuce contains the following components: erucic acid: cis-CH3 (CH2) 7ch = ch (CH2)11cooh name: cis-13- eicosanoic acid.
Question 3: Is lettuce really free of bugs? A few days ago, the mobile phone newspaper I subscribed to published such a little knowledge: "Why there are no bugs in lettuce-because lettuce is an exotic variety, and there are no bugs suitable for it here in Asia." As a matter of fact, I know that lettuce here will have worms. And this little knowledge will mislead many people. If you want to know more about the relationship between vegetables and pests, listen to me slowly and tell you in detail: lettuce has two kinds of leaves and stems, and leaves are generally called lettuce instead of lettuce; Most people who use stems are called lettuce, and a few locals are also called lettuce. For the convenience of description, this paper separates the two, lettuce refers to the stem and lettuce refers to the leaf. The vegetables we usually eat belong to many families and genera, and can also be subdivided into roots (such as radish, turnip, burdock, etc. ) and stems (including underground stems) are divided according to their main edible parts. Such as potatoes, ginger, lettuce and so on. ), leaves (such as Chinese cabbage, spinach, celery, etc. ), flowers (such as cauliflower, day lily, etc. ), fruits (such as eggplant fruits such as peppers, beans such as kidney beans, melons such as cucumbers), seeds (such as green beans and green peas), and sprouts (such as Toona sinensis buds, mung bean sprouts, bamboo shoots, etc.). ). Vegetables in a broad sense also include some aquatic plants (such as kelp) and edible fungi. Let's talk about some common vegetable pests: 1 and Pieris rapae (larvae of Pieris rapae), which mainly harm cruciferous vegetables, because these vegetables, especially cauliflower, have a special smell, and Pieris rapae likes to lay eggs on them. 2. Caterpillars (larvae of Plutella xylostella) are the same as Pieris rapae. 3. Bean borer (pod borer larva) mainly harms the flowers and fruits of beans, kidney beans and lentils. 4, cotton bollworm, in addition to cotton, corn and other crops, but also harm peppers, kidney beans (kidney beans), beans (cowpeas), tomatoes and so on. 5. Leek maggots (Lepidoptera larvae) mainly harm leeks, onions, garlic, onions, lettuce and cruciferous vegetables. 6. Garlic maggots (larvae of onion flies) mainly harm onions and garlic. 7. The adult and larva of Coccinella octopusilla mainly harm the leaves of eggplant and potato. We usually can't see eggplant and potatoes when we eat them. 8. Aphids mainly harm plant buds, mainly Chinese cabbage, radish, turnip, pepper, lettuce and so on. 9. Liriomyza sativae and Liriomyza sativae do harm to plants in a wide range, mainly to the leaves of plants, and can harm Chinese cabbage, celery, lettuce and lettuce in leafy vegetables. In addition, there are whiteflies, thrips, flea beetles, underground grubs (larvae of big black scarab), ground tigers, ground maggots (larvae of gadfly) and other pests. As you can see above, lettuce and lettuce pests at least include aphids and leaf miners. Under normal circumstances, the harm of liriomyza sativae takes some time to appear, but the lettuce we usually eat has a short growth period, so we can rarely see liriomyza sativae grow up. In fact, as long as you observe carefully, you may see the damage caused by liriomyza sativae on the back of the old lettuce leaves that have been thrown away. In addition, it is not because exotic plants will avoid being harmed by local pests. In modern China, many kinds of plants were introduced from abroad, which will be damaged by pests after a long time.
Question 4: Why are there no bugs in lettuce? Or why don't bugs eat lettuce? Because there are few bugs that can live on lettuce in Asia at present.
Question 5: Is it true that lettuce is worm-free? Why? Lettuce is sweet and cool, because its stems and leaves contain lettuce, so it is slightly bitter and not easy to get insects.
Question 6: Why don't lettuce get worms? Lettuce belongs to Compositae, also known as leaf lettuce.
Generally, cruciferous vegetables like Dabai,
Most vegetable worms only eat cruciferous vegetables, so lettuce rarely appears ~ ~
Question 7: Is it true that there are bugs on lettuce on the balcony? Are the eggs on lettuce leaves not parasites in the stomach, but parasites in the human body, such as tapeworms and roundworms? The eggs of ordinary caterpillars, aphids and butterflies will not survive, because: first, they may be chewed and eggs will not produce worms. Second, the role of gastric acid can also kill eggs. However, eating lettuce infected with ascaris eggs may parasitize the human body and turn it into a worm. Because vegetable farmers are used to using manure as fertilizer, vegetables are easily polluted by parasite eggs. Ascaris eggs are hard to be recognized by naked eyes, and are about (45-75)μm×(35-50) μ m, showing a white spherical shape. The intermediate host of Taenia solium is pig. People can only get tapeworms if they eat pork infected with eggs, and there will be no tapeworm eggs on raw vegetable leaves. Moreover, tapeworm eggs are large and easy to distinguish, and tapeworm meat is not allowed to be sold in the market. In short, we must pay attention to food hygiene. Try to eat cooked vegetables and wash lettuce several times. In addition, for the sake of safety, it is recommended to go to the hospital for parasite examination to determine whether it is infected with parasites.
Question 8: Why don't bugs eat lettuce? Lettuce contains lettuce and erucic acid, which is a white milky liquid, slightly bitter and can repel insects. It has a special smell and is destructive to insects. People have an enzyme that can destroy erucic acid, so it is harmless for people to eat lettuce. In addition, rapeseed, bitter herb, lettuce and sweet potato leaves are all unwilling to be eaten by insects. Only in extreme cases, such as when there are no other plants, will insects visit these plants.