Common pests of rice

Many pests are often encountered in the process of planting rice, which eat the roots of plants and endanger the growth and development of plants. What are the common pests of rice? How to prevent and cure it?

Common Rice pests and their Control

1. Cnaphalocrocis medinalis

(1) introduction: Rice leaf borer, commonly known as curly leaf worm, bract leaf worm, white leaf worm, etc., is a frequent major rice pest in China, which generally reduces rice yield by 10-20%, more than 50% in severe cases, and even leads to no yield.

The adult of rice leaf roller is a small yellow moth with a length of 8 mm and black stripes on its wings. The larva is a light green long-shaped fleshworm. The larva rolls up the rice leaves longitudinally to form an insect bud and hides in the bud to eat the leaf flesh. When the insect bud occurs, the rice field is withered and white, resulting in great losses. The rice leaf roller larva moves flexibly and retreats or falls to the ground as soon as it is alarmed.

(2) Control methods: strengthen fertilizer and water management, rational fertilization, carry out biological control, use pine caterpillar Trichogramma and Australian Trichogramma in the peak period of moth, and apply pesticides in 5-7 days after the peak of moth or during the peak period of 2nd instar larvae. Commonly used agents are: avermectin and abamectin compound, 2.8% avermectin + 3% flurosemide (gold standard) application time is better in the morning and evening, all day in cloudy days, if the drug is used in drizzle days, the pesticide concentration should be increased.

2. Rice planthopper

(1) introduction: the main occurrence in rice field is white-backed planthopper and brown planthopper. Generally speaking, it is mainly white-backed planthopper in the early stage of rice and brown planthopper in the later stage. That is, the white-backed planthopper is mainly damaged from tillering to jointing stage.

In the affected fields, the rice leaves turned yellow and the tillers decreased, and in serious cases, the rice died in the "falling pond". Brown planthopper is mainly damaged from booting to maturity. When the damage is serious, the base of the rice clump becomes dark brown, the whole plant dies gradually, and the damaged field is often "yellow pond". In serious cases, the whole field is yellow and burning.

(2) Prevention and control methods: reasonable close planting, pay attention to the rational use of nitrogen, phosphorus and potassium fertilizer, the pesticides used are as follows: in the initial peak period of young nymphs, 25% buprofezil wettable powder is sprayed with 25-30 grams of water and 50-60 kilograms of water per mu. You can also use 10% cicada powder wettable powder 200-250 grams per mu, or 25% aldicarb wettable powder 100-150 grams per mu, or 40% omethoate 100-150 grams per mu, 50-60 kg water.

3. Drillworms

(1) introduction: there are three species of heart-drilling insects, including Chilo suppressalis, Chilo suppressalis and Chilo suppressalis. When the mature larvae overwintered in the stump of rice, the three kinds of larvae were eaten by larvae in rice. In different growth stages of rice, the damaged plants could form withered heart, withered sheath, insect-injured plant, withered booting and white panicle. The larvae of Chilo suppressalis are reddish brown, the larvae of Chilo suppressalis are dark brown with five longitudinal lines on the back, and the larvae of Chilo suppressalis are yellowish green.

(2) Control methods: after rice harvest, pick out the straw away from the rice field, expose it to the sun for a few days, and kill the borer in the straw. In terms of drug use, 25% insecticidal double aqueous agent 200-250 ml, 80% insecticidal single powder 35-40 g, 90% crystal trichlorfon 100-200 g, 40% dimethoate EC 100 g, 20% triazophos EC 100 ml, 5% fipronil suspension 30 ml, etc., choose a spray with 50-60 kg of water. You can also use 25% insecticidal double water agent 200-250 ml, 5% insecticidal double granule 1-1.5 kg, choose one of which can be mixed with 20 kg of moist fine soil, sprinkle it in the paddy field and keep a shallow water layer of 3-5 cm for 3-5 days.

4. Rice thrips

(1) introduction: commonly known as gray worm. Adult and nymphs file the leaf surface with mouthparts and form fine yellow-white spots, the leaf tips are rolled inward, and the whole leaves curl and wither yellow. in the rice fields with heavy damage in the early stage of tillering, the seedlings are not long, the roots are not hairy, there are no tillers, and even die in clumps.

(2) Control methods: combined with fertilizer accumulation in winter and spring, weeds on the edge of the field and ditch were eradicated, and the dead branches and leaves beside the ridge of the field were removed.

During the incubation period, the commonly used agents are: 100ml / mu with 40% omethoate EC, or 50% phoxim EC 100ml, spray with 50-60kg water, or 0.5-1g / mu with 70% Amelol water dispersible granules, spray with 15-30kg water, or soak the seedling tip with 1000 times of 40% omethoate EC during the seedling field period.

5. Rice stalk fly

(1) introduction: also known as Liriomyza huidobrensis. Rice stalk flies harm the heart leaves, growth points and young panicles of rice by burrowing larvae into rice stems.

(2) Control methods: in the use of pesticides, the peak period of adults and the incubation period of eggs are the appropriate period for control, or when there are 3-4 insects per square meter in the seedling field or 1-2 insects per 100 clumps of rice in the field. Use 100-200 grams of 90% crystal trichlorfon, 100 grams of 50% fenitrothion EC, 10-20 grams of 10% imidacloprid wettable powder, 50 grams of 80% dichlorvos EC, 50 grams of 40% dimethoate EC, and choose a spray of 50-60 kg water.

6. Oxya chinensis

The main results are as follows: (1) introduction: the adults and nymphs of rice locusts bite off the leaves and eat up the leaves in severe cases. In the later stage of rice growth, rice locusts also bite off rice ears and feed on grains.

(2) Prevention and control methods: clear ditches, remove weeds, and protect the natural enemies of rice locusts such as frogs, spiders, dragonflies, mantis and so on. When the rice locust entered the rice field, when there were more than 10 rice locusts in 100 rice plants, the pesticide was sprayed out from the middle of the rice field in the early morning or after 4 o'clock in the afternoon when the rice locust entered the paddy field. You can use 90% crystal trichlorfon 100-200 g, 80% dichlorvos EC 50-80 g, 40% dimethoate EC 30-40 g, 40% phoxim EC 40 g per mu, and choose a spray of 50-60 kg water.

7. Rice bract worm

(1) introduction: alias rice butterfly, the larva is 2-3 cm long, the head is light brown, there is a "w"-shaped brown pattern in the center of the head, the body is yellowish green, and there is a dark green line on the back. The larvae spin silk to bind several rice leaves together to form a cylindrical longitudinally rolled bud, and the larvae hide in the bud to feed.

(2) Control methods: eradicate weeds on the edge of fields and ditches in winter and spring; when the occurrence quantity is not large, pick insect buds manually and kill larvae. It is forbidden to apply highly toxic pesticides to protect parasitoids, bugs and other natural enemies. In the use of insecticides, when there are 10-15 insects per 100 clumps of rice, the insecticides are applied at the young instar stage of the larvae. Use 90% crystal trichlorfon 100 grams + washing powder 25 grams, 50% fenitrothion EC 125 ml, 80% dichlorvos EC 75-100 ml, choose a spray with 50-60 kg water.

8. Rice negative mud worm

(1) introduction: commonly known as back dung bug, pig shit bug, red head worm. Adults and larvae feed on the mesophyll of rice leaves, making the leaves form white stripes. when the number of insects is large, the leaves leave only a layer of transparent epidermis, the whole leaves are white and scorched, and the whole plant dies in serious cases.

(2) Control methods: eradicate weeds at the edge of fields and ditches in winter, and eliminate the sources of insects that pass the winter. The occurrence of heavy paddy fields in mountainous areas should be strengthened. In the 1-2 instar stage of larvae, 90% crystal trichlorfon 100-200 grams, 25% quinathion EC 25-30 grams per mu, 40 grams phoxim EC 40 grams per mu, 80% dichlorvos EC 50-80 milliliters per mu, etc., choose a spray of 50-60 kg water. If the number of insects is large, it should be prevented again every 10 days or so after application.

The above is the basic introduction to the insect pests that may be encountered in rice, for reference only. I hope it will be helpful to everyone.