There are many types of pests in rape, including locusts, stem worms, cabbage pods, cabbage butterfly, leaf miner and triceps. In recent years, locusts, stem weevil, and diamondback moth have been seriously endangered, which seriously affected the yield and quality of rapeseed. The rapeseed pests and their control are summarized as follows: First, the damage characteristics 1. Aphids are generally collected by their adult and nymphs in the back of the rape leaves, heart leaves and the top of the inflorescence and other parts of the sucking juice, so that the damaged rape leaves yellow, curl or even fall off, and can also spread viral disease, so that the stem branches of the shuttle-like disease Varieties, tender stems, and young fruit malformations, poor seed maturation, seriously affect the yield and quality of rapeseed. 2. Stem larvae mainly larvae drill larvae, causing them to enlarge and form hollow marrow, resulting in plant malformation, poor lodging resistance, easy to fold, severe convulsions, and even death. 3. The newly hatched larvae of Plutella xylostella can be fed with leaves in the human leaf tissue. After the 2nd instar, the foraging leaves left a layer of epidermis. In 3rd and 4th instar larvae, the leaves were formed into holes and nicks. In severe cases, the leaves were eaten into a net shape. Rapeseed poses a great threat. 4. The young larvae of the cabbage white butterfly feed on the leaf flesh and form transparent holes. After 2 years of age, they are scattered and infested, eating the leaves into a net shape or nicking. When severe, the whole leaf eaten, leaving only the petiole and the main vein. However, the body of the old larvae is as long as 3?4cm, which is 3-4 times that of the diamondback moth. 5. Leafminers often eat leaf meat as larvae, forming a gray curved submerged passage, which seriously affects the photosynthesis of rapeseed. 6. The flea beetles feed on the leaves of adults and form holes, which can harm Nenying fruit. The larvae eat the root bark and affect the growth of roots and the absorption of water nutrients. Second, the law of damage 1. Infestation period: Aphids, Plutella xylostella and Flea beetles can all be harmed during the whole growing period of rapeseed. Overwinter adults of stem weevil are generally unearthed from late February to mid-March, and are harmed during the rape bud stage. Cabbage butterfly is mainly found in rape seedlings. The period of damage, leaf miner is mainly in the late growth of rape damage. 2. Insects in the period of damage: The fleas mainly feed on the leaves of adults, while other pests mainly use larvae to harm rape plants. 3. Breeding is fast, the number is large, and some pests alternate seriously. Aphids can reproduce for 1 generation at 5 to 6 days at higher temperatures. Up to 30 larvae can be found on each stem, and 120 on cabbage females, up to 500 in total. Plutella xylostella can be used for one year. Several generations to more than a dozen generations have occurred, and the number of breedings is large. Flea beetles and leaf miners can occur for several generations, among which overwintering flea beetles can produce 500-600 eggs, and leafflies can lay 40-40 eggs during their lifetime. 4. Concealed, strong escape. The larvae of the stem weevil and the leafminer are harmed inside the plant. The adults of the beetle larvae often hide in the roots and soil of the rapeseed. The adult larvae of the diamondback moth and the cabbage caterpillar have pseudo-deadness, which will prevent the work. Bring great difficulties. III. Comprehensive prevention and control According to the pest damage characteristics and laws of rapeseeds, seize the key period of prevention and control, targeted, to achieve the effect of “defense early, prevent small, prevent less, preventâ€, and ensure that rapeseed increase production and income. 1. The critical period of pest control: A.m. and stems (especially stems of A.) must seize the active period of adult emergence before spawning, generally in the middle and late March of February, all over the world due to terrain and climate differences. Prevention. The cabbage butterfly should do prevention work during the seedling stage of rapeseed. Before and after the flowering period of the rapeseed, the larvae of the diamondback moth and the leaf miner could change according to the pest situation. In March and April, attention should be paid to prevention and control. 2. Agricultural Prevention and Control: The "three early dates" of agricultural control should be implemented to reduce the number of insects. (1) Early removal of weeds, diseases, and old leaves of weeds and rapeseed fields in the spring and deep burial or incineration in order to eliminate the source of overwintering insects. (2) Early irrigation of green shoots at early time can make some of the overwintering pests be killed by mud or water flooding, especially for the control of aphid, stem weevil and aphid. (3) Early cultivating and top dressing in order to achieve the purpose of raising temperature, keeping crops, weeding, and eradicating the source of insects, promoting long-term stable growth of rapeseed and enhancing resistance, but the cultivator should be shallow and not deep enough to prevent cutting off the root system. 3. Chemical control: Chemical control must be applied in a timely and appropriate manner and scientifically. At the same time, attention should be paid to alternate administration of each drug to reduce the resistance of insect pests and improve the effect of drug use. (1) Spraying: Nehalothrin (40% omethoate EC plus 20% extinguishment of diced EC) per 667 m2 at the onset and inception of pests, Pythium pyruvate (40% monocrotophos 2.5% of the enemy kills the EC) or extinct 2000 times 50kg spray, exerting its triple role in stomach poisoning, contact killing and sucking, and has good control effect on all pests. The use of avermectin (AVMs) and other drugs for the exchange of diamondback moths is more effective. (2) Dusting: Control of locusts, stems and armor by spraying 1.5% dimethoate powder or 2.5% trichlorfon powder for 2 kg per 667 square meters. (3) Trapping: Use 3% brown sugar water, add 0.5% trichlorfon to make venom, spray in the field, trap and kill the adults of the leaf miner; use living vegetables in the nylon net and hang in the field. , It is trapped under a 1cm basin or venom to kill small caterpillars. (4) Smearing stems: If the stems of the stem beetles are not controlled in time or have poor results, the adults have spawned their stems or larvae have hatched in the stems of the stems, can be rapeseed oil or waste oil and monocrotophos or oxidized music If you mix 3:17. Use a cotton ball to spread the liquid on the stem below the spawning hole. The effect is excellent. 4. Physical control: trapped winged aphids on a yellow plate coated with vaseline or waste engine oil; adult insects of Plutella xylostella were killed by black light or frequency-vibration lamp. 5. Biological control: Control of aphids, diamondback moth, cabbage whitefly and leafminer, etc. using acaricidal bacteria, insecticidal bacteria or Bt emulsion, or breeding and using natural enemies such as parasitic wasps.
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