Rice leaves have leaf insects, what pesticides are used to smelt them?

1. Harmful symptoms

Rice leaf roller borer is a common pest on rice, commonly known as leaf roller, with larvae as the pest of rice, the rice leaves are longitudinally rolled bracts, and feed on the mesophyll on the leaves, leaving only the white lower epidermis, forming white stripes. The light damage in the early stage of rice is unlikely to affect the yield, but the occurrence of severe damage will not affect the tillering and heading in the later stage, and the occurrence of heavy rice in the middle and late stages of rice will lead to the decrease of 1000-grain weight and the increase of empty grains, resulting in the reduction of yield.

2. Occurrence characteristics

The occurrence of rice leaf rollers has a lot to do with climatic conditions (high air currents, temperature, humidity).。Rice leaf rollers have long-distance migration, prefer warmth and high humidity, and are more than 80% at a temperature of 22-28 and a relative humidity of more than 80%, which is conducive to adult development and mating, oviposition and hatching, and larval growth.

Rice leaf borer.

There are two common species of rice leaf rollers in China: rice longitudinal leaf rollersMoth, rice longitudinal leaf roller borer (also known as yellow longitudinal leaf rollerMoth, is an approximation of the former). According to the survey, the reason why the leaf roller is difficult to fight this year is that the rare rice longitudinal leaf roller borer has broken out in recent years, followed by a large occurrence base and a large insect age, and its population may be more resistant to conventional pesticides.

In the past, the rice longitudinal leaf roller borer only occurred locally in Sichuan, Chongqing and other places, and it was often mixed with the rice leaf roller.

The difference between rice leaf roller and rice leaf roller.

The difference between rice leaf roller and rice leaf roller. From the larvae, the larvae of the rice longitudinal leaf roller borer are pale yellow, and there are bristles on the insects; Adults can see the pattern, such as the midline of the forewings of the rice longitudinal leaf roller borer is long, reaching the posterior edge of the forewing, and the midline of the forewings of the rice leaf roller borer is very short and does not reach the middle of the wing.

1. Reasonable selection of agents

The pesticides that can be selected to control rice leaf roller are:Abamectin, emamectin benzoate (abbreviation of emamectin benzoate), indoxacarb, chlorantraniliprole, emamectin benzoate, chlorfenapyr, emamectin benzoate, indoxacarb, etc., organic rice can choose matrine, azadirachtin, Bacillus thuringiensis, Spodoptera exigua karyotype polyhedrovirus and other biological pesticides.

Rice leaf borer.

According to recent feedback, it is difficult to control rice longitudinal leaf roller with avermectin, emamectin benzoate and chlorantraniliprole; The use of pyroxonil and indoworm vitis mite urea additives has a very good effect, and the insects can be controlled and cleaned in 2 days.

According to the control experience, the control of rice longitudinal leaf borer can be selected:Emamectin benzoate, indoxacarb, emamectin benzoate, indocarcarb plus lice carica, emamectin salt + lice carica, emamectin benzoate and chlorfenapyr plus lice carica, etc., plus organosilicon additives or other high-efficiency additives, are conducive to improving the insecticidal effect.

2. Pesticide application method

Before application, the severity of insect pests in the field should be observed, and then targeted pesticide application, the pest pests are serious, the insect age is large, and the dosage of pesticides should be appropriately increased; The application time is better in the evening or before the morning dew dries, and the application is better in the evening, and the medicine can be used all day on cloudy days to avoid high temperature and rainy days. Evenly spray the liquid on the bract of rice leaves, and irrigate a shallow water layer of 3-5 cm for 3-4 days during the application period.

You can use plant-specific insect repellent to spray evenly on the plant leaves, and it is not advisable to water during the medication, otherwise there is no effect, and you can spray it several times to consolidate the effect.

There are many pesticides for the control of rice leaf rollers, such as avermectin, emamectin, emamectin, emamectin, Bacillus thuringiensis, amide chronic insecticides, etc.

Rice leaf curls can be culled with cypermethrin, but the application must be sprayed before the rice leaf curling is completed or before dusk. Emamectin benzoate, indiscarb, Bacillus thuringiensis, and organosilicon spray were used for prevention and control, and the effect was better. Rice seed leaf borer can be controlled with avermectin, avermectin, 100 grams per mu, mixed with 30 kg of water foliar spray.

When is the control effect of rice longitudinal leaf roller good? The key period for the control of rice leaf roller is from the end of egg hatching to the first and second instar of larvae, and the control effect is better during this time period. Leave a shallow water layer when applying, spray evenly, and focus on spraying on the new leaf parts and the back of the leaves; According to the habit of transplanting the rice leaf roller borer, it is advisable to apply the pesticide before 10 a.m. and after 5 p.m.

Control methods of rice leaf rollers.

1.Strengthen fertilizer and water management and rational fertilization.

The green and dense rice fields are strong insect attractants and are susceptible to damage. Therefore, it is important to avoid partial application of nitrogen fertilizer to prevent the rice plants from being green and tender during the peak stage of adults, and attracting adults to lay eggs in the field.

2.Exterminate adult insects.

Large-scale unified defense and control of rice areas can be found in the first.

Second, the third generation of adults appear at the peak of the period, 40% chlorpyrifos emulsifiable concentrate 40 50 ml per mu can be sprayed, and 50 kg of dilution per mu can kill a large number of female moths that have not laid eggs, which can play a role in controlling the harm. This control measure has a large workload, and if there is no unified control and control alone, the adults in other fields or weeds will move in, and the control effect is not good.

3.Control of larvae.

is the most commonly used and most effective method. Spraying the following agents at the peak of egg incubation and the peak of larval incubation can obtain better control effects: 10 ml of 10% chlorantranimide suspension per mu, or avermectin EC 40 50 ml, 5% emamectin benzoate microemulsion 15 20 ml, or 4000IU Bacillus thuringiensis 40 50 ml, or 15% Avi?

Toxic emulsifiable concentrate 50 70 ml, spray on 50 kg of water. The best time to spray in the morning or evening on a sunny day should be evenly and thoughtfully. If it is in the peak period of egg hatching, if it is raining continuously, you can seize the gap between the rain and spray, otherwise it is most likely to cause serious damage in this case.

Chlorantraniliprole and emamectin benzoate and profenofos are recommended for rice leaf rollers.

When using these agents, it is necessary to follow the dosage and usage instructions to avoid overdose and cause drug damage. In addition, in order to avoid the emergence of drug resistance, it is recommended to alternately use different kinds of pesticides in Laoshan, or use them together with additives such as silicones, to improve the control effect. Don't use the same drug all the time, as this can easily cause the leaf roller to produce stronger antibodies.

In addition to chemical control, biological and agricultural control measures can also be adopted, such as stocking natural enemies such as red-eyed bees, or strengthening field management to improve the resistance of rice. At the same time, it is necessary to pay attention to the selection of rice varieties, different varieties have different resistance to leaf rollers, and the selection of varieties with strong resistance can reduce the use of pesticides and the cost of control.

Hazards of leaf rollers

1. Destroy plant growth: Leaf curlers feed on plant leaves, roll up the leaves and grow in them, resulting in leaf damage and photosynthesis hindering, affecting the normal growth and development of plants.

2. Reduce plant yield: leaf rollers harm plant growth and lead to a decrease in plant yield. Especially in crops and cash crops, the damage of leaf rollers has a great impact on farmers' production and economic income.

3. Increase the vulnerability of plants: leaf curlers harm plant growth, causing plants to become fragile and vulnerable to attacks by other pests and natural enemies. Leaf curlers feed on plant leaves, roll them up and grow in them, causing a great impact on the photosynthesis and growth of plants.

<> the harm of rice leaf roller is greater, and in severe cases, it can cause rice yield reduction. For rice leaf roller larvae, spraying pesticides can be sprayed at the peak of egg incubation and larvae at the peak of larval incubation, and sprayed with 10 ml of 10% chlorantranimide suspension per mu, or 40-50 ml of avermectin EC, or 15-20 ml of 5% emamectin benzoate microemulsion on 50 kg of water, and the application time is selected in the morning or evening of a sunny day.

First, the harm of rice leaf roller is not great

Rice leaf roller is very harmful, and when the damage is serious, it will lead to a decrease in rice yield. It mainly harms rice, followed by wheat, millet, sugarcane and grasses weeds, etc., the hatching larvae will first move in the leaf sheath of the plant, and eat the heart leaves, with the increase of insect age, the larvae will roll the leaves into a cylinder, and hide in the mesophyll to eat the mesophyll, the larvae can continue to harm multiple leaves, damage at the rice seedling stage will seriously affect its growth, severe death, damage in the tillering period to the jointing stage, will lead to a decrease in tillering, the growth period is delayed.

2. What pesticides are good for rice leaf rollers?

1. Prevention and control of adult insects: first.

When the second and third generations of adults appear at their peak, spray 40-50 ml of 40% chlorpyrifos EC per mu, and use 50 kg of dilution per mu to kill a large number of female moths that are pregnant with eggs and have not laid eggs, which can effectively play a role in prevention and control.

2. Prevention and control of larvae: spray pesticides in the peak period of egg incubation and the peak stage of young larvae, spray 10 ml of 10% chlorantranimide suspension per mu, or 40-50 ml of avermectin emulsifiable concentrate, or 15-20 ml of 5% emamectin benzoate microemulsion, or 4000IU 40-50 ml of Bacillus thuringiensis 50 kg of spray on water, and spray it in the morning or evening on a sunny day.

3. Prevention and control of other pests of rice

1. Rice borer: mainly do a good job in the prevention and control of 2 generations of 2 borers, which can be sprinkled with 5% insecticidal double large granules per mu, or 150-200 ml of 25% insecticidal double aqueous agent, or 100 ml of 25% insecticidal double aqueous agent plus 100 ml of BT emulsion mixed with 60-75 kg of conventional spray with water.

2. Rice planthopper: control when the amount of insects per 100 bushes reaches more than 1,500, use 20-25 grams of parachlorphanum wettable powder per mu, or 20-25 grams of 25% eutopic wettable powder, and mix 75-100 kg of conventional spray with water.

Older borers are not effective with any medicine, because it has already penetrated.

Rice borer (large borer, dimorphic borer, etc.). It can be sprayed with chlorantraniliprole, Bacillus thuringiensis, indoxacarb, fiproramide and other agents.

The control of borer worm must be carried out before the borer drills (preferably from the peak of egg hatching to the 1st instar larval stage), and the effect will be good.

<> the following agents can be used to control rice leaf borer: 50 insecticidal double soluble powder 700 times, 80 insecticidal stuffy single soluble powder 1000 times, 42 trik emulsifiable concentrate 800 times, 10 imidacloprid wettable powder 2000 times, 20 hydrazine wettable stalking powder 2000 times, 55 special kill borer wettable powder 1000 times, 40 chlorpyrifos Kaixiang emulsifiable concentrate 1000 times, etc.

Avermectin, emamectin benzoate.

Abamectin has a history of more than 10 years in the control of rice leaf roller, the resistance is increasing, the dosage is increasing, because avermectin has no systemic property, so avermectin has a shorter control effect on leaf roller, when the leaf roller borer generations overlap, avermectin protection time is shorter, and it is recommended to add chlorantraniliprole and other use together in the actual application of deficiency. Emamectin benzoate is a derivative of avermectin, the activity is higher than that of avermectin, and the resistance is small, but the same protection time is too short, at present, avermectin and emamectin salt are mainly used to control the leaf roller borer of older rice.

Bisamide insecticides.

Diamide insecticides include chlorantraniliprole, flubenziliprole, tetrachlorantraniliprole, etc., this kind of insecticide for leaf roller borer control time is longer, belongs to long-term insecticides, but the speed of the brigade is lacking in this effect, at present, it is generally used in combination with avermectin, emamectin salt, etc., flubenzaniliprole will be banned from being used on rice after October this year.

Other insecticides such as indoxacarb.

In our practice, for the leaf roller borer with greater avermectin resistance, avi indoxacarb can be used to control it, and the effect is still good.