Corn Laodelphax striatellus generally occurs in East China, Central China and North China. The main harm of Laodelphax striatellus to maize is to spread maize rough dwarf virus. Once corn is infected, it is almost out of control, and the yield is reduced by more than 30%, so corn rough dwarf disease is also called corn cancer.
morphological character
Adults: 3.5 mm for males and 4.0 mm for females; Short-winged males are 2.3 mm, females are 2.5 mm, and the yellow females on the top of the head and chest backboard are light yellow in the middle and dark brown on both sides. The front wings are almost transparent and have wing spots. The male insects on the ventral surface of the chest and abdomen are dark brown, the female insects are yellowish brown and the feet are light brown. Egg: oval, slightly curved, long 1.0 mm, with the front end thinner than the back end, initially milky white and later yellowish.
Prevention and control strategy
Agricultural control:
1. advocate not planting spring corn. In recent years, it is in the epidemic year of maize rough dwarf disease. If we reform the farming system, plant other crops instead of spring corn, and cut off the transmission route of the virus source, we can eliminate the disease as soon as possible.
2. Selecting resistant varieties is the most economical and effective way to solve the harm of maize rough dwarf disease. There are some differences in disease resistance of different maize varieties to rough dwarf disease.
3. Laodelphax striatellus can spread in a short distance and migrate in a long distance with high-altitude airflow, which requires unified prevention and control, unified time and joint prevention and control. Weeds on the ground, roadside and ditches should also be sprayed with pesticides, and herbicides such as paraquat and glyphosate should be added to kill weeds, which will destroy insect habitats and reduce insect populations.
Chemical control:
Chemical control should grasp four key periods and select low-toxicity and high-efficiency pesticides in order to achieve good results.
(1) Corn seeds were treated with seed coating agent or corn seed dressing agent containing systemic pesticides during sowing period to drive away Laodelphax striatellus, and at the same time, it can also play a good role in preventing and treating seed poisoning.
(2) Wheat Filling Stage The early stage of wheat filling is the key period to control the first generation of Laodelphax striatellus nymphs. At this time, the development trends of Laodelphax striatellus should be grasped in time, centralized and unified drug use should be carried out in the peak period of young nymphs, and systemic pesticides such as imidacloprid (10g/ mu) or chlorpyrifos (50g/ mu) should be sprayed in wheat fields, roadsides and ditches.
(3) Due to the tendency of Laodelphax striatellus turning green at the mature stage of wheat, a large number of Laodelphax striatellus adults migrated from wheat fields to surrounding spring corn fields at the end of May and the beginning of June, which did harm to spring corn seedlings. At this time, 3-5 leaves of maize seedlings are in the sensitive period.
Therefore, it is necessary to seize the opportunity to use 50 grams of chlorpyrifos or 20-30 grams of imidacloprid mixed with A50 grams per mu at the early stage of the migration of Laodelphax striatellus, and spray water 1 time every 3-5 days for 3-4 times, which has a good preventive effect on the disease.
(4) At the initial stage of infection, 20 ml of 4.5% beta-cypermethrin can be used, which can be effectively controlled by spraying after adding special liquid fertilizer for corn. The use of antiviral drugs must highlight the word "early". After the five-leaf stage of maize, its control effect will be poor.
2. Spodoptera punctata
Lepidoptera Noctuidae is a new pest in summer corn area of China, which is often mistaken for the harm of cutworms everywhere. With the growth of larvae, the food intake of pests will continue to increase, and the occurrence range will be further expanded. If it is not controlled in time, it will seriously threaten corn production. Therefore, it is necessary to strengthen the monitoring of the occurrence dynamics of Spodoptera litura, do a good job in forecasting or early warning the insect situation, guide farmers to prevent and control it in time, and reduce its damage losses.
morphological character
Morphology of pupa and egg: the pupa is about 10 mm long, and it is yellow-brown at the initial stage of pupation and gradually turns brown. Egg-shaped steamed bread with longitudinal ridges, yellow-green at the beginning and yellow at the back. Less than one millimeter in diameter; Egg yield per unit area is based on wheat straw. A female moth can lay hundreds of eggs.
Larvae morphology: the mature larvae are 14~ 18 mm in length, up to 20 mm in length, yellow-black to dark brown, with brown head.
Morphology of mature larvae: forehead is dark brown, forehead is yellow, and forehead seam is yellowish brown. There are two brown back lines on the back of abdomen, which disappear to the chest, and there is an inverted triangle dark brown stripe on the front edge of each back. The valve is black, the upper line of the valve is dark brown and the lower line of the valve is white. Smooth body surface. Fake death, curled up in a c shape after being scared.
Adult morphology: The adult of Spodoptera litura is 10— 12mm in length, grayish brown, with dark gray front wings with 1 white spots and black spots on it. The hind wings are silver-gray and shiny.
Prevention and control strategy
Agricultural prevention and control: sowing corn after stubble removal by using stubble remover or shallow rotary tillage before sowing after wheat harvest can effectively reduce the harm of Spodoptera litura and improve the sowing quality of corn, which can be planted in Miao Zhuang; Carry out manual weeding and chemical weeding in time, remove wheat stubble and wheat straw stubble, and reduce the environmental conditions for pest breeding; Improve sowing quality, cultivate strong seedlings and improve pest resistance.
Chemical control:
The best time to control corn larvae by coating before the third instar is before emergence (before sowing and after sowing).
Poison bait spreading: 4-500g of fried wheat bran or crushed fried cottonseed cake per mu is mixed with 90% crystal trichlorfon or 48% chlorpyrifos emulsifiable solution to prepare poison bait, and then it is spread along the ridge of corn seedlings in the evening, and toxic soil is spread. 300 ~ 500ml of 80% dichlorvos emulsifiable concentrate mixed with 25kg of fine soil was spread on the ridge of corn seedlings in the morning, and the control effect was good.
Irrigation, (65,438+0) water, 48% chlorpyrifos EC 65,438+0 kg/mu when watering the field. (2) Spraying corn seedlings, you can unscrew the nozzle and drop the liquid medicine one by one along the stem, or spray the roots with a straight nozzle. The chemical agent can be 48% chlorpyrifos EC 1500 times solution, 30% acephate EC 1000 times solution, 2.5% beta-cypermethrin EC 2500 times solution or 4.5% beta-cypermethrin. The amount of liquid medicine should be large to ensure that it penetrates into the hiding place of pests around the root of corn about 30cm.
3. Corn thrips
There are two generations of parthenogenesis in maize, which is mainly caused by adults feeding on maize. In Beijing, the damage period is around mid-June, which is the wheat harvest season, so it is easy to be ignored and cause serious harm. The yellow-breasted thrips mainly harms the seedling stage, and the number of corn yellow-breasted thrips is more in the seedling stage and the heart stage, and then it gradually decreases. When spring corn and medium-mature corn have passed the heart leaf stage or the end of heart leaf stage in late June, thrips turn to summer sowing corn and sorghum at seedling stage.
morphological character
Female adults are divided into long wings, half wings and short wings. Small, dark yellow, with dark gray spots on the chest. The front wings are grayish yellow, long and narrow, and there are a few but significant veins and long hair on the wing margin. The length of the semi-long wing is only the fifth section of the abdomen at most, and the short wing is slightly bud-like in the Yangtze River Delta. Egg kidney-shaped, milky white to milky yellow. If the insect's body color is milky blue or milky yellow, there are laterally raised particles on the body surface. Pupa or pre-pupa (that is, third-instar insects) is light yellow, with white wing buds and brown pupa pieces when they emerge.
Prevention and control strategy
Agricultural control: rational close planting, timely watering, timely removal of weeds, effectively reducing the harm of thrips.
Drug control: When thrips are seriously harmful, they should be sprayed with chemicals in time for control. 10% imidacloprid wettable powder 2000 times solution, chlorpyrifos imidacloprid EC 2500 times solution or fenvalerate EC 3000 times solution can be used for spraying.
Manual control: For "whiplike" corn seedlings, an awl can be used to plunge into the base of whiplike leaves and let them open in the middle, so that the heart leaves can resume normal growth.
4, corn armyworm
Corn armyworm is one of the common main pests in corn crops. It belongs to LEPIDOPTERA, Noctuidae, also known as marching insects, with a body length of 17-20 mm, light grayish brown or yellowish brown, and the male moth is darker in color. Larvae overeat corn leaves, and when it is serious, it will eat up the leaves in a short time, resulting in reduced production or even no harvest. Three generations can occur in a year, and the second generation mainly harms summer corn. Natural enemies mainly include walking nails, frogs, birds, parasitic bees and parasitic flies.
morphological character
Adult body length 15- 17mm, wing spread 36-40 mm. The head and chest are grayish brown and the abdomen is dark brown. The front wings are grayish yellow, yellow or orange, which varies greatly; There are often only a few black spots on the inner transverse line, the ring and renal line are brown, the boundary is not obvious, and the renal line,
There is a white spot on the back end and a black spot on both sides; The lateral horizontal line is a row of black spots; The minor edge line inclines inward from the apex angle to MZ; The edge line is a row of black dots. The hind wings are dark brown and gradually fade toward the base. The egg is about 0.5mm long and hemispherical, and the primary white gradually turns yellow and shiny. Eggs are arranged in rows and blocks in a single layer. The mature larvae are 38 mm long. The head is reddish brown, the skull is reticulate, the forehead is flat, there are thick brown longitudinal stripes on both sides, slightly splayed, and there is a brown reticulation on the outside. The body color changes greatly, from light green to thick black; When it happens, the back is often black, the ventral surface is light and dirty, the midline of the back is white, the sub-dorsal line between the upper valve lines is slightly blue, and the valve lines and the lower valve lines are pink to grayish white. There is a dark brown wide longitudinal band on the outside of the abdominal foot, and a semicircular dark brown toe hook on the toe. Pupa length is about19mm; Reddish brown; There is a row of dentate points on the front edge of the back of the 5-7 abdominal segments; There are four spines on the buttock spine, two in the middle are thick, and the short spines on both sides are slightly curved.
Prevention and control strategy
For the control of adults, we should use the phototaxis and chemotaxis of armyworm adults, and adopt pollution-free control techniques such as sweet and sour solution, sex lure and insecticidal lamp to trap and kill adults, so as to reduce the amount of eggs laid by adults and reduce the population density in the field. The control time of larvae in most areas of the province is in early September, and the control target field is middle-late mature summer corn field, and the control index is the population density of 30 heads per 100 plants in corn field. When using 50% phoxim EC 75-100g, 40% chlorpyrifos EC 75-100g, or 20% diflubenzuron No.3 suspension concentrate 500-1000g, spray 40kg evenly.
5. Corn borer
Corn borer, commonly known as axis worm, corn borer, etc. , belonging to Lepidoptera borer family. Corn borer is a worldwide pest, which harms more than 50 species of host/kloc-0, among which corn is the most harmful. It can cause 5- 15% yield loss every year.
Dangerous characteristics
Adult: The adult of Asian corn borer is 13- 15 mm in length, with dark brown wavy inner transverse lines and dark brown serrated outer transverse lines on the yellow (female) or yellow-brown (male) front wings.
Eggs: 20 ~ 60 eggs of corn borer are arranged in irregular scales, and the single egg is oval and flat. It is milky white (like wax drops) during production and gradually turns pale yellow, with black spots in the center before hatching (commonly known as black eggs).
Larvae: Asian corn borer larvae are 65438 0.5 mm long when they are first hatched, and the head shell is milky white and translucent. Mature larvae are 20-30mm long, with brown-black head and shell, white dirty body and obvious back hair.
Pupa: The pupa of Asian corn borer is 15- 19mm, spindle-shaped, yellow-brown, with wavy transverse wrinkles on the back, dark brown buttocks and 5-8 upward-curved bristles at the end.
Prevention and control strategy
Before overwintering larvae emerge, it is an effective measure to treat the stems of overwintering hosts such as corn, sorghum and cotton to eliminate overwintering larvae and reduce the source base of overwintering insects. In the third generation area, the sowing area of summer corn should be expanded as much as possible, the spring sowing area of host crops such as corn, sorghum and millet should be compressed, and the food source and breeding ground of 1 generation corn borer should be reduced to control the occurrence of the second and third generations and reduce the harm to summer corn.
Taking advantage of the habit that female moths like to lay eggs on tall, dense and vigorous host plants, about 1 month before the normal sowing of spring corn, we choose plots near the wintering ground to plant small areas of trapping zones and trapping fields, or strengthen the fertilizer and water management of a few early sowing spring corn fields to promote their early development and lure integrated insects to lay eggs.
Planting moth-resistant varieties is an economical, effective and safe measure to control moths. Combined with the field management measures of some crops, especially the measures of thinning seedlings, fixing seedlings, cutting cotton, harrowing and topping, the insects and eggs can be directly removed, which is more closely related to the prevention and control of corn borer. If 1 generation corn borer harms cotton seedlings, the infected plants can be removed by combining thinning seedlings with fixed seedlings; The young larvae of the second generation corn borer first harm the tender head and petiole of cotton, and then eat the stem. By pruning and topping, the damaged petioles, tender shoots and branches can be removed and taken out to the field for centralized treatment, which can obviously reduce the harm of corn borer to cotton.
Physical control: use high-pressure mercury lamp to trap insects. The specific method is to install 200W or 400W high-pressure mercury lamps in a relatively open place in the village at a distance of 150m (200m with 400W bulbs). The light bulb should be mounted on a waterproof lamp holder and fixed with iron wire. A circular pool with a diameter of lm, brick structure and cement structure can be built under the lamp. You can also dig a pit of the same size under the lamp, and lay plastic sheets in the pit, but they are all watertight. Drain the water into the pool to a depth of 6cm, add about 100g washing powder, and stir well. Generally, change water 1 time every 3 days, and add washing powder. If the water change time is not up and the water in the pool is insufficient, it can be replenished at any time. The light bulb should be hung in the center of the pool, at a distance of 15cm from the water surface. From the early stage to the late stage of overwintering adult emergence, the lights are turned on at 20:30 every day and turned off at 4:00 the next morning. Because of the large amount of moths usually attracted, the moths in the pond should be fished out and buried deeply every morning.
Biological control: from mid-April to early May every year, before the overwintering larvae pupate, Beauveria bassiana spore powder is used to spray powder on the burned host crop straw and root stubble, and the dosage of bacterial powder is100g/m3; Spray 1 point per square meter on the stack surface until bacterial powder can be seen on the stack surface. Or in the middle period of heart leaves, 0.5 kg of Beauveria bassiana spore powder with a bacterial content of 654.38+00 billion-50 billion /g is mixed with the cinder screened by skg to make Beauveria bassiana granules with a ratio of 654.38+0: 654.38+00, and each plant is applied to the heart leaves of corn. 8000IU/mg Bacillus thuringiensis wettable powder (3kg/ mu) was mixed with 10kg fine sand to make granules, which were applied to the middle stage of corn heart leaves, and the control effect was good. Intercropping summer corn with mung bean can increase the population of parasitic bees such as Trichogramma in nature and control the occurrence of moth damage. Or multiply and release parasitic bees to control moths. In addition, the sex pheromone of corn borer can be used to trap and kill male insects or put a lot of sex pheromones, which makes it difficult for male insects to find female insects to mate. The best time to control corn borer is the end of heart leaf, that is, the big trumpet stage, which is also the key period to control corn borer.
6, locusts
Locusts are ORTHOPTERA insects of Acridoidea. Commonly known as "grasshopper", there are many kinds, with more than 10000 species in the world. Distributed in tropical and temperate grasslands and desert areas all over the world.
morphological character
The mouthparts are hard, and the front wings are narrow and tough, covering the back wings. Thin hind wings, suitable for flying, developed hind limbs and good at jumping.
Prevention and control strategy
Agricultural prevention and control: build water conservancy to ensure drought and flood; Reclaim wasteland on a large scale, change locust habitat and reduce the area of occurrence base; Planting trees, changing the microclimate in locust areas and reducing the suitable places for locust spawning and reproduction; Improve cultivation techniques to control locust eggs, adjust measures to local conditions, change crop layout and reduce locust harm.
Biological control: In locust-infested areas, agricultural and biological pesticides with high efficiency and low toxicity are used to protect predatory natural enemies in locust-infested areas. Large-scale application of microsporidia locusts.
Chemical control: When chemical agents are used to control locusts in a large area, locusts should be mastered before the age of 3. Spraying 75% malathion EC with ultra-low or low volume. Aircraft control 60 ~ 70g per mu; Ground spraying: 75g/mu, or 45% malathion ultra-low volume emulsifiable concentrate, 75-100g/mu, or 20% mixture of enemy and horse, or 1.5% lindane powder, per mu1.5-.
7. Corn aphids
Corn aphid is a pest, which can harm corn, rice and many grasses. At seedling stage, adult aphids and nymphae aphids cluster in the heart leaves, which damage the ears after heading, suck juice, hinder growth and spread a variety of Gramineae cereal viruses. Natural enemies include Harmonia axyridis, Harmonia septempunctata, Harmonia japonica, Syrphidae, Chrysopa lacewing and parasitic bees.
morphological character
Wingless parthenocarpy fruit is oval in shape, ranging from 1.8mm-2.2mm in length. Live insects are dark green, xx thin, with black appendages and reddish brown compound eyes. The 7th section of the abdomen is black, and the 8th section has a horizontal band on the back and a net pattern on the body surface. Antennas, beaks, feet, abdominal tubes and tails are all black. The antenna has six sections, which is longer than the fuselage length of 1/3. The beak is thick and short, not reaching the basal segment of the midfoot, and the distal segment is 1.7 times the width of the basal segment. The abdominal tube is long and cylindrical, the end is contracted, and the abdominal tube is imbricated. The tail is conical with 4 to 5 hairs.
The winged parthenogenetic aphid is ovoid, with a body length of 1.6 mm to 1.8 mm, a shiny black head and chest, a yellowish red to dark green abdomen, and dark side spots in front of the abdominal tube. The antenna is 6 segments shorter than the fuselage, and its length is 65438+ 0/3 of the fuselage length. Antennas, beaks, feet, abdominal nodes, abdominal tubes and tails are black. There are 1 pairs of large marginal spots in 2-4 abdominal segments, dorsal transverse bands in 6 and 7 abdominal segments, and intermediate bands in 8 abdominal segments. Other characteristics are similar to those of wingless type. Oval.
Prevention and control strategy
Agricultural control: The cultivation mode of wheat interplanting corn is 10 ~ 15 days earlier than that of wheat sowing corn, which can avoid the peak of aphid reproduction and reduce the harm.
On the basis of prediction, according to the number of aphids, the percentage of natural enemy units in the number of aphids, climatic conditions and the occurrence of aphids were investigated to determine the types and periods of drug use.
Chemical control: The seeds were soaked with1%imidacloprid wettable powder with the weight of 0. 1%, and the control effect on aphids, thrips and planthoppers at seedling stage was excellent 25 days after sowing.
When corn entered the jointing stage, it was found that the central aphid plant could be sprayed with 0.5% dimethoate powder or 40% dimethoate EC 1500 times. When the aphid plant rate reaches 30% to 40% and "oil plants" (honey dew) appear, the whole field should be treated.
Spraying Fauci+Imidacloprid or thiamethoxam at the end of corn.
8. Spodoptera exigua
Spodoptera exigua, whose scientific name is Spodoptera exigua, belongs to Lepidoptera and Noctuidae. It is an omnivorous pest that mainly harms vegetables and occurs intermittently all over the world. Harm green onion, cabbage, Chinese cabbage, celery, cauliflower, carrot, asparagus, spinach, amaranth, pepper, cowpea, cauliflower, eggplant, kale, tomato, Chinese cabbage, broccoli, spinach, radish and other vegetables.
morphological character
The body color of larvae varies greatly, such as green, dark green, brown, dark brown and so on. The lower line of the ventral lateral valve is obviously yellow-white longitudinal band, sometimes pink. Adults lie down during the day and come out at night, with strong phototaxis and weak chemotaxis. Older larvae have suspended animation, and mature larvae spin silks underground to pupate.
Prevention and control strategy
Agricultural control: pupating in cultivated land in late autumn and early winter; Manually remove egg pieces and insect leaves.
Physical control: black light traps and kills adults.
Chemical control:
To catch 1~2 instar larvae for control, the following chemicals can be selected for spraying:
5% chlorhexidine EC 4000 times solution
Or 4,000 times of 5% carbendazim EC.
It is still 4000 times that of 5% Nong Mengte EC.
Or 20% diflubenzuron suspension concentrate 500~ 1000 times.
Or 500- 1000 times of 25% diflubenzuron No.3 suspension.
Or 2000-3000 times of 40% Juma EC.
Or 2000-3000 times of 40% Juma EC.
Or 20% fenvalerate 2000-4000 times solution.
Or 500 times of anisodamine pesticide solution.
9, corn spider mite
Corn Tetranychus urticae is a red spider, belonging to Arachnoidea and Tetranychidae, and it is a polyphagous pest. Nymphs or adults suck juice on the back of leaves, causing the leaves to die and affecting the yield.
morphological character
The body color of adult mites changes with the seasons, generally red or rust red, and the female mites are round and about 0.55 mm long. The male worm is oval. Young mites are nearly round, transparent in color, with red eyes and three pairs of feet. After feeding, their bodies turn dark green. If a mite has four pairs of feet, its body becomes dark and obvious block pigments appear on its sides.
Prevention and control strategy
According to the biological habits of jujube spiders, agricultural, physical and chemical control measures can be taken.
Artificial control: scrape bark and burn it centrally before the overwintering eggs hatch. After scraping, paint white (limewater) on the trunk to kill most of the overwintering eggs.
Agricultural control: according to the hatching law of overwintering eggs and the habit of feeding and breeding on weeds first after hatching, the red spider was turned over in early spring to remove weeds on the ground and keep the field free of weeds during the incubation period, so that the red spider died because it could not find food.
Physical control: Before the jujube tree germinates and the jujube red spider is about to harm the tree (about late April), a closed adhesive ring with a width of about 1 cm can be applied to the trunk to prevent the jujube red spider from moving to the tree, and the effect can reach more than 95%.
Biological control: There are many kinds of jujube red spiders in the field. According to the investigation, there are mainly Chrysopa sinica, mite-eating ladybug and predatory mites, among which Chrysopa sinica has a large population and a large predation on jujube red spider. Protecting and increasing the number of natural enemies can enhance its control of jujube red spider.
Chemical control: 1000~ 1500 times of 40% dicofol EC, 2000 times of 20% Migujing WP, 2000 times of 15% pyridaben EC and 1.8% avermectin EC can be used.
When damaged plants are found in the field, 1 ~3 leaves with mites (eggs) should be pulled out in time to control mite damage. The picked leaves shall be bagged and buried deeply or burned, and shall not be used as feed or human manure pile.
10, snail
Snails belong to the phylum Mollusca, Gastropoda. Snails not only harm plant buds and leaves, but also cause lack of seedlings and broken ridges, which is one of the important pests in agriculture.
morphological character
Snails are hermaphroditic and cross-pollinated animals. The mating time is usually at dusk, night or rainy day. They begin to lay eggs about 15 days after mating. They can lay eggs 4-6 times a year, each time 150-200, and the eggs hatch in 10- 18 days. The newly hatched larvae only feed on the mesophyll of crops and leave the epidermis. When they grow up, they often eat the leaves of crops into holes or gaps. Its eating habits are miscellaneous, which can harm many vegetables and other crops such as Cruciferae, Leguminosae and Solanaceae. Snails lie down during the day and come out at night. Most of them start foraging after 6 pm, and reach the peak at 8 pm to 1 1. After midnight, their food intake gradually decreases, and they stop foraging in the early morning and dive into the soil or shelter. Snails like dark and humid environment, can move around the clock and feed in rainy days or after watering.
Prevention and control strategy
According to the biological habits of Oncomelania hupensis, agricultural, physical and chemical control measures can be taken.
Artificial control: before sunrise in the morning or in rainy days, when the snail activity is harmful, the ground and plants should be caught artificially in time.
Agricultural prevention and control: often clean up the fields, destroy the habitats and spawning sites of Oncomelania hupensis, and reduce the source of insects. Deep ploughing in autumn and winter can turn eggs and overwintering adults to the surface, so that they can be dried or eaten by natural enemies. In areas with serious snail disasters, a small piece of weed land is left when the land is ploughed in winter, spring and autumn to attract snails and then focus on eliminating them.
Physical control: sprinkle a layer of quicklime around the plant in time, but not on the front of the crop leaves, so as not to affect photosynthesis. Snails will lose water when they come out for food at night and encounter quicklime. Or sprinkle quicklime on the farmland ridges to form a blockade zone, and use 5-7 kilograms of quicklime per mu, which is not effective when the ground is wet.
Chemical control: in the full bloom period of snails, 600g of 10% snail (polyacetal) granules should be used per mu, and evenly sprinkled on the border in the evening, or the granules should be applied to the lower ground of plants; You can also choose 30-60 grams of 80% tetraacetaldehyde per mu and spray it with water. The second prevention and control of the snail reappearing field every 10- 15 days can effectively control the harm of snails. Please refer to the instructions for the specific usage and dosage of pesticides.