What about the camellias? control of diseases and insect pests of camellias / 4 insect pests and 3 diseases

As one of the top ten famous flowers in China, the beauty of camellia is beyond doubt. Its beautiful flowers, bright colors and charming fragrance are all beloved by people. However, because it is not maintained according to the culture method of camellias, the plant will grow insects and get sick, thus seriously affecting the ornamental, what about the camellia worms? The following is the pest control of camellias selected by the editor. Go in and have a look!

First, what to do with the camellia worms to determine the pests

The beauty of camellias lies in its beautiful appearance. If the appearance is destroyed by pests and diseases, it is distressing, then how to deal with camellias? At this point, we should identify insect pests and then spray them against the use of medicine. Generally speaking, there are 7 kinds of diseases and insect pests of camellias, including 4 insect pests and 3 diseases, specific symptoms and control methods, we go on.

II. Disease and pest control of camellias

(1) insect pests of camellias

1. Red spider

One of the main pests of camellias, it mainly harms the back of leaves and survives by sucking the sap of camellias leaves. Symptoms of damage: the plant will become malnourished and may show symptoms of yellowing or even shedding of camellia leaves.

Control method: when the red spider is found, the whole camellia plant should be thoroughly washed with large water, and then 2000 times of triclofenac EC should be sprayed, which can be effective several times in a row.

2. Aphids

An insect that infects camellias, which parasites on leaves and absorbs juice, mainly harming young leaves and stems. Once aphids appear, they are dense and look very scary. Not only that, honeydew secreted by aphids can attract ants and cause soot or other fungal diseases.

Control methods: when there are a small number of aphids, you can kill them manually, such as picking with needles or brushing them off with tools such as a brush; when there are many aphids, spray them with 2.5% fish rattan essential EC 1200 times.

3. Scale insects

Another insect pest of camellias, it mainly harms young leaves and sucks the juice of flowers. Symptoms of damage: Camellia leaves from green to gray-green, and finally to yellow, serious, the branches and leaves are covered with shell insects, resulting in the whole plant withered.

Control methods: when there are few shell insects, rinse with water, or wipe the diseased plants with liquor, vinegar, alcohol, washing powder, etc., have a certain curative effect; scale insects for a long time, use 550% marathon, 40% dimethoate 0.1% solution to kill in turn, a few times will be effective.

4. Leaf roll moth

The insect has a small body and is one of the main pests that invade camellias. its larvae bite the new buds, tender leaves and flower buds of the plant, leaving only the epidermis in a reticulate shape, and make the leaves curl longitudinally and continuously harm the plants in the hidden leaves, seriously affecting the growth and flowering of the plants.

Control methods: when the leaf roll moth is small, the rolled leaves can be removed manually and the insect body can be pinched to death; in the larval stage, 1000 phoxim can be sprayed at night; in adults, sugar and vinegar solution (5 parts of sugar, 5 parts of wine, 80 parts of water) can be used to trap and kill. Harm.

(2) Diseases of camellias

1. Anthrax

This disease is one of the common diseases of camellia, which usually occurs on the leaves of flower seedlings from June to July. Symptoms: watery green-brown disease spots appeared on the edge of camellia leaves, and then expanded into a layer of small black spots arranged in irregular large stripes spread throughout the leaves, and finally caused the leaves to fall off.

Prevention and treatment methods: when the above diseases are found, the diseased leaves are removed and burned in time to reduce the source of the disease; at the initial stage of the disease, 70% methyl topiramate wettable powder 1000Mel 1500 times can be sprayed for prevention and treatment.

2. Leaf spot

One of the main diseases of camellias, in the environment of high temperature, high humidity and poor ventilation, the leaves of camellias are easy to be infected with leaf spot. Symptoms: the leaves appear light yellow and reddish yellow spots, and then expand into a round or oval shape; if the environment is relatively humid, black granular substances may appear on the disease spots, and the leaves will dry up and fall off in the later stage.

Prevention and control methods: find a small number of diseased leaves, remove and burn them in time, in order to reduce the source of the disease; in severe cases, use 1000-1500 times of deemulsified oil for prevention and treatment, spray 25% 2-3 times every 7-15 days, and it will be effective after several times.

3. Bituminous coal disease

The disease can damage the branches and leaves of camellias, especially on the leaves. At the initial stage of the disease, the camellia leaves appeared soot-like mildew spots, and then gradually expanded and connected to each other into pieces, so that most of the plants were covered by soot-like mildew layer, seriously affecting plant photosynthesis and respiration, resulting in the phenomenon of camellia leaves.

Prevention and treatment: when the above diseases are found, Baume 0.3 degree stone sulfur mixture can be sprayed once every 10 cents for 15 days, for a total of 3-4 times. In addition, 50% topazine wettable powder can also be sprayed 500 times, 7 Mel once every 10 days, and the effect can be seen after spraying 3 times.

What about the growth of tea plum leaves? pest control of tea plum / 4 insect pests and 3 diseases

As a combination of camellias and plum blossoms, the beauty of Camellia is beyond doubt. Its beautiful leaves, gorgeous colors and charming fragrance are all beloved by people. However, due to some reasons, tea plum will grow insect disease, thus seriously affecting the ornamental, then tea plum leaf worm how to do? The following is the pest control of tea plum selected by the editor. Go in and have a look!

First, what to do with the growing insects in the leaves of tea plum, to determine the pests

Tea plum is very resistant, so it is supposed to be very difficult to get sick and insect pests, but if we do not raise tea plum according to the culture method, it is also normal for tea plum leaves to grow insects. At this time, we can not be in a hurry, but first determine the pests, and then spray for the use of medicine. Generally speaking, there are 7 kinds of diseases and insect pests of tea plum, including 4 insect pests and 3 diseases, specific symptoms and control methods, we go on.

II. Disease and pest control of tea plum

1. Aphids

An insect that infects tea plum, which parasites on leaves and absorbs juice, mainly harming young leaves and stems. Once aphids appear, they are dense and look very scary.

Control methods: when there are a small number of aphids, you can kill them manually, such as picking with needles or brushing them off with tools such as a brush; when there are many aphids, spray them with 2.5% fish rattan essential EC 1200 times.

2. Diamondback moth

One of the diseases and insect pests of tea plum, which usually occurs from June to October. The larvae of the insect will feed on the lower epidermis and mesophyll of the leaves, and in severe cases, only the upper epidermis is left; the adults of the diamondback moth are more harmful, and it can eat up the leaves, leaving only the main veins, seriously affecting the flower bud differentiation, flowering and ornamental of tea plum.

Prevention and control methods: in the initial stage, spray 50% fenitrothion EC 800x liquid, or use biological preparation Bt water agent 1000 times liquid spray in cloudy days, the prevention and control effect is good. If it is in winter, you can dig the cocoon in the soil around the tea plum, break it or knock the cocoon off the tree trunk.

3. Scale insects

Another pest of tea plum, which mainly harms young leaves and sucks the juice of flowers. Symptoms of damage: tea plum leaves from green to gray-green, and finally to yellow, which is also one of the reasons for tea plum leaves yellowing; in serious cases, the branches and leaves are covered with shell insects, resulting in the death of the whole plant.

Control methods: when there are few shell insects, rinse with water, or wipe the diseased plants with liquor, vinegar, alcohol, washing powder, etc., have a certain curative effect; scale insects for a long time, use 550% marathon, 40% dimethoate 0.1% solution to kill in turn, a few times will be effective.

4. Longicorn beetles

The insect is divided into tea longicorn beetles and tea black tarsal longicorn beetles, both of which are harmful to tea plum. The former mainly eats the roots of tea plum and the branches near the ground, while the latter damages the branches from the bottom up, causing the branches to swell and wither and die.

Prevention and control methods: after the discovery of longicorn beetles, adults can be caught manually, or 800 times of 50% fenitrothion EC can be sprayed, or green green buds can be sprayed to kill adults.

5. Anthrax

This disease is one of the common diseases of tea plum, which usually occurs from June to July and mainly harms adult leaves. Symptoms of the disease: water-stained green-brown disease spots appeared on the edge and tip of tea plum leaves, and then expanded into a layer of small black spots arranged in irregular stripes to spread throughout the leaves, resulting in the loss of tea plum leaves.

Prevention and treatment methods: find the above symptoms, remove the diseased leaves and burn them in time to reduce the source of the disease; at the initial stage of the disease, spray 2-3 times with anthrax Fumei or 75% chlorothalonil 600 times, or spray 1-2 times with 12% green copper emulsion during budding and leaf development.

6. Leaf spot

One of the main diseases of tea plum, in the environment of high temperature, high humidity and poor ventilation, the leaves of tea plum are easy to be infected with leaf spot disease. Symptoms: the leaves appear yellowish and reddish yellow spots, and then enlarged into a round or oval shape.

Prevention and treatment methods: if the above disease occurs and a small number of diseased leaves are found, it should be removed and burned in time to reduce the source of the disease; when the disease is serious, it can be prevented and treated with 1000-1500 times of demulsified oil, spraying 25% 2-3 times every 7-15 days, and it will be effective after a few times.

7. Coal pollution disease

One of the diseases and insect pests of tea plum, it generally occurs in the environment of high temperature, high humidity and poor ventilation. Symptoms: the leaves and branches of Camellia oleifera are covered with a layer of black soot, which affects the photosynthesis and respiration of the leaves, causing poor growth and early defoliation.

Prevention and treatment methods: when the above symptoms are found, 50% carbendazim 600 times solution or 70% mancozeb 600 times solution is sprayed in turn, and the effect can be seen after 2-3 times.

Primary color map of diseases and insect pests of camellia

Primary color map of diseases and insect pests of camellia

Scab disease

Plant diseases caused mainly by Elsinoe and S-phaceloma in fungi. Xanthomonas in bacteria and Streptomyces in actinomycetes can also cause scab. The affected site forms rough, slightly raised, scab-like or cork-shaped, round or oval spots, with central cracking or subsidence. The symptoms of stem pod, melon and fruit, root tuber and tuber were the most obvious. In severe cases, the disease spot is connected into pieces, the fruit is deformed, and the fleshy rhizome is dysplastic. The leaves were damaged and the young plants were killed. The bacteria overwintered in the diseased tissue or branches, the bacteria in the aboveground part were transmitted by wind and rain, the bacteria in the underground part were spread by the movement of water in the soil and the activities of underground organisms, and the seeds or plants with bacteria could spread over a long distance. Generally through the removal of diseased and disabled tissue, the application of organic fertilizer, growing period spraying and other measures. Control methods: ① strengthen management, apply more potash fertilizer, make the new shoots neatly and rapidly mature, do a good job of garden cleaning and pruning in winter, so as to improve the disease resistance of trees. ② chemical protection: in spring and early summer, Rain Water is more and the temperature is not very high, the disease is serious when the fog is thick and the water is heavy in the morning, so it is necessary to spray chemicals to protect the tender leaves. Agents for the prevention and treatment of canker and anthrax can be selected. The damaged leaves appeared waterlogged round spots at the initial stage, and then turned waxy yellow. The disease spot expands with the growth of the leaf, and gradually cork, protruding to one side of the leaf shows a conical scab, the other side is sunken inward, the leaves with many disease spots are twisted and deformed, seriously causing defoliation. The pathogen overwintered in the tissue of the disease department, and the optimum temperature for development was 16-23 ℃. When the temperature was above 15 ℃ in the overcast, rainy and humid weather in spring, conidia were produced and the disease was transmitted by wind, rain and insects. Air humidity in spring is the main factor to determine whether the disease is serious or not. The disease is prevalent in spring and late autumn shoots in case of continuous rain and heavy fog in the morning, but rarely occurs in summer due to high temperature. Prevention and control methods (1) pay attention to the selection of seedlings: disease-free seedlings should be selected in the new nursery to avoid transporting seedlings and taking scions in the disease area. (2) strengthen cultivation management: do a good job of garden cleaning and pruning in winter, and the diseased branches and fallen leaves should be centrally burned. Thinning and deleting dense branches, improving the ventilation and light transmission conditions in the crown, and reducing the air humidity in the crown. (3) spraying control: the disease only infects young tissue, so it is necessary to protect spring shoots, late autumn shoots and young fruits. The first spray is when the spring bud grows 2 mm, the second spray is in the flowering stage, and the spray in the late autumn tip depends on the weather. Available pesticides are: spray 0.3% 0.5% Bordeaux solution before infection, or 30% copper oxychloride 500 times 600 times solution, or 75% chlorothalonil wettable powder 500 times solution, or 50% chlorothalonil wettable powder 500 times solution preventive protection. The impregnated and dyed can be sprayed with 50% Topurazine wettable powder 600 times 800 times liquid and other internal inhalation fungicides.

Anthrax

[etiology and symptoms] the disease was caused by the infection of camellia leaves by Colletotrichum gloeosporoides. This is the main disease of camellias, with an incidence of 33%. The disease often occurs at the leaf margin, leaf tip and both sides of the leaf vein. Dark green markings appear at first, and then gradually expand into irregular Taipan, the color from brown to black, serious can spread to the whole leaf, causing a large number of fallen leaves.

The occurrence of the disease is closely related to temperature and temperature. In general, the optimal temperature for the disease was 25-28 ℃. When the temperature is suitable and the humidity increases, especially the continuous rainfall, it can promote the spread and development of the disease. Generally, the disease began in April, reached the peak from June to July, and tended to stop after September. [prevention and treatment methods] ① completely removed the diseased leaves. ② cut off the diseased branches in winter. ③ sprays 1% Bordeaux solution every half a month before the onset of the disease each year. ④ was sprayed with 600-fold chlorothalonil solution once a week for 3 consecutive 4 times. ⑤ strengthens cultivation management, scientific weeding and fertilization. Phosphorus and potassium fertilizer can be increased in spring, and 0.15% potassium dihydrogen phosphate aqueous solution is sprayed before the leaves are unfolded. Algal spot disease

[etiology and symptoms] the disease is caused by parasitic rust algae (Cephaleuros virescens). Disease spots can appear on both sides of the leaf, but mainly on the leaf surface. At the beginning, it was a small gray-green dot in the shape of a needle, and then gradually expanded outward in the form of radiation, forming an approximate round or irregular spot. The disease spot is obviously raised, and there are fine striped felt on the surface. In the later stage, the color of the lesion changed from grayish green to dark brown. Due to the cover of pathogens, the foliar photosynthesis is affected, which weakens the growth of camellia plants.

[incidence regularity] parasitic rust algae overwintered as filamentous nutrients in parasitic tissue, produced zoospores under wet conditions, and spores invaded new plants to make them get sick. The pathogen is a weak parasite. Under the condition of high temperature and high temperature, the disease is the most serious in the camellia forest which grows badly because of poor ventilation and light transmission. [control methods] ① should strengthen cultivation management, reasonable fertilization and timely pruning, so as to avoid excessive shade of camellia woodland and make it ventilated and transparent, so as to improve camellia resistance. ② can be prevented by spraying 0.2%-0.5% copper sulfate solution. Root rot disease

[etiology and symptoms] the disease is caused by a variety of pathogenic fungi, the most common of which are Phytophthora cinnamoni, Cylindrocladium crotalariae and Armillaria, which mainly infect the root system of camellia. The roots of the damaged plants rotted and turned black, the leaves turned yellow, the tip died, the flower buds fell, and the plants gradually withered and died.

[incidence regularity] the pathogen overwintered on the soil or diseased plant with sclerotia. In the following spring, when the temperature and humidity were suitable, the sclerotia germinated and spread in the soil, invading the roots of the plant. The higher the temperature, the higher the incidence. [prevention and control methods] ① should timely dig up the diseased plant and the bacteria-carrying soil near it, and disinfect the soil around the diseased plant with 1% copper sulfate solution to prevent the spread of bacteria. ② keeps the soil well drained and strictly prevents the accumulation of water in the cultivated land. ③ selected camellia varieties with strong disease resistance for cultivation. Flower rot

[etiology and symptoms] the disease is caused by camellia flower rot fungi (Giborinia camelliae Kohn) infecting petals. The injured flowers first appeared brown spots, and then gradually expanded until the whole flower turned brown and withered.

[incidence regularity] Flower rot fungi can form sclerotia on the flower stalk, and their spores can spread with the wind. The incidence is generally low in autumn. From December to March of the following year, the damage rate of flowers increased with the increase of temperature. [prevention and treatment] when ① finds camellias infected with this disease, they should be removed in time and burned centrally. Especially in the flowering period, it is necessary to clean up the diseased flowers that fall on the ground in time. Before flowering, ② can use fungicides, such as carbendazim, to spray buds for 2 or 3 times. Most of the camellias in ③ were planted in autumn, or the middle and late flowers were treated with gibberellin to make them bloom in autumn in order to avoid the peak of camellia flower rot fungi. Biological control method was used in ④. Sporidesmium sclerotivorum and Coniotnyrium minitans fungi were inoculated into the soil to kill the spores of the pathogen. ⑤ do not buy and cultivate camellia plants with flower rot. Withered branch disease

A disease caused by pathogenic fungi infecting twigs or old branches of camellia. The damaged branches were necrotic, the leaves changed from green to yellowish, dried up and fell off gradually from the top down, and finally the whole shoot withered and died.

Prevention and control methods 1. Cut off the diseased branches and burn them in winter. two。 Remove useless adventitious buds and weak branches and reduce pathogens as epiphytic sites. three. The diseased plants were isolated and maintained. 4. Before the camellia plant sprouted, it was sprayed with methyl topiramate, thiram, chlorothalonil and other fungicides. 5. Apply more phosphorus and potassium fertilizer and less nitrogen fertilizer. Rust wall lice (rust spider) belongs to acaridae, gall mites family, the insect body is very small, with nymphs or adults harm young leaves, twigs, absorb juice. There were many small reddish brown spots on the back of the damaged leaves, and gradually expanded and appeared many reticular white cracks, the surface yellowed and lost luster, and the lower curvature of both sides and top of the leaves were atrophied to deciduous leaves, mainly the summer and autumn shoots of seedlings and young trees suffered more seriously. Prevention and control methods: 1. Spray stone-sulfur mixture, acaricide and malathion, 1.8% avermectin 5000 times liquid plus 4.5% high-efficiency permethrin 1500 times liquid or 15% chlorpromazine 2000ml 3000 times liquid spray; you can also use 50 grams of washing powder, 10 milliliters of diesel oil and 10 liters of water to evenly spray.

two。 Rust wall lice reproduce most rapidly in high temperature and dry climate, so it is necessary to cool and spray water in the nursery, and cut off the leaves damaged by rust tick lice in time.

Leaf mite

[for control methods, please see "Rust tick"]

Soot disease Camellia is affected by soot disease, its surface produces a dark brown to dark brown mildew layer, and then the mildew layer thickens into soot. Due to the different types of pathogens, mildew varies in the later stage, such as small black particles scattered on the mildew layer (that is, conidium or cyst shell) or bristle-shaped long conidial protuberance, and in the orchard where the disease occurs seriously, the canopy is covered with soot. [etiology]: there are many pathogens of the disease, except for the pure parasitism of soot, the other genera are epiphytic bacteria. The forms of the pathogens are different, but the mycelium is dark brown, forming asexual and sexual vegetative forms on the surface of the host. Ascospores dark brown or colorless, with one to several septate; closed cysts stipitate or sessile, with or without accessory filaments and bristles outside the shell. The hyphae of Capnodiunsp. Are filamentous, conidia unicellular, oval or oval, smooth and colorless. There are tube-shaped or nearly rod-shaped conidium densely in the mycelium, the end of which is dilated, round and dark brown, and the conidium is attached to the inflated part. The ascus is globose or oblate, membranous, dark, with orifices at the top of the vesicle, and superficial setae. The ascomycetes are rod-shaped and endophytic with 8 ascospores. The spores are long oval with diaphragm and brown. [occurrence regularity]: the disease overwintered in the diseased part with mycelia, conidia and closed cysts. In the following year, under suitable conditions of temperature and humidity, spores were propagated and spread to the host (litchi tree) by wind and rain. The secretions of shell insects, white moth wax cicada, whitefly, leaf gall mites and other pests were used as nutrition, grew and propagated, and spread infection and damage. Where the occurrence of the above-mentioned pests is common and serious in the orchard, it is beneficial to the epidemic of the disease. [prevention and control methods]: (1) Agricultural prevention and control: strengthen the management of camellias, adhere to rational fertilization, moderate pruning, remove diseased branches, facilitate ventilation and light transmission, enhance tree potential and reduce disease.

(2) Pesticide control: ① was used to control insect pests such as shell insects, white moth, wax cicada, whitefly and other piercing mouthparts, and reduce the pathogenic factors. For the patients with severe disease, ② should be administered twice continuously and sprayed once every 10 days. The selected medicaments are: 70% methyl thiophanate wettable powder, or 75% chlorothalonil wettable powder, 600 times the liquid mixed at 1:1, or 77% thiazolyl wettable powder, or 0.3% chlorothalonil 0.5% Bordeaux solution, etc.

Shell worm

There are more than 30 species of common scale insects, among which the most serious damage to camellias are bran shield, blowing cotton and red wax.

Shell insects should be parasitic on the branches and leaves of camellias, especially on the main vein, leaf margin and back of the leaves, and pierce the mesophyll or branch cortex tissue with piercing mouthparts to absorb nutrients. It makes the leaves appear sunken yellow spots, or white cotton-like patches on the back of the leaves, or pink nodule-like protuberances on the branches, and the leaves turn yellow, curl, or even fall off. The plant grew poorly and the buds fell. When camellia is cultivated indoors and in greenhouse, it is vulnerable to shell insects if it is not well ventilated. Improve the ventilation and light transmission conditions of camellias and inhibit the growth and reproduction of scale insects. [treatment] 1. During the incubation period of the scale insect, spraying a higher concentration of insecticide can be controlled or washed with a 1000-fold solution of 48% Lesbon EC. You can also use a 40% omethoate 5-fold solution coating rod. 45% malathion EC 1000 times liquid spray. Under the conditions of high temperature, high humidity and poor ventilation, especially during the long time in the greenhouse in autumn and winter, the stems and leaves are prone to scale insects. Strengthen ventilation and light transmission, and pay attention to the control of environmental humidity. If you find a small amount of live worms, wipe them off with a wet cloth in time, or you can use transparent tape to remove them. For productive cultivation, the nymphs can be sprayed with 1500 times of 25% buprofezin wettable powder during the peak incubation period. Frenzied scale killing has a special effect on the control of shell insects, and 800 times liquid of killing scale is used to spray evenly. 2. Soil method can be used to control camellias when there are not many camellias in the family. For example, it can be sprayed with an aqueous solution of washing powder. I have used "insecticidal aerosol" spray, it also has a very good effect, friends can also try. Bud worm

[morphology and harm] aphids are divided into winged aphids and wingless aphids. Winged viviparous female aphid, transparent wings, dark brown body; wingless viviparous female aphid, wingless, dark brown body. In addition, if the early appearance is similar to the adult, the body is wingless and yellowish. Adults and nymphs gather on the tender shoots of camellias to absorb juice, which shrinks the bud leaves of the injured camellias and seriously affects their growth. The excrement of aphids can cause bituminous coal disease.

[control methods] during the peak period of early occurrence of aphids, ① sprayed camellia plants with 50% phosphamine emulsion 2000 times or 50% dimethoate emulsion 1000 times, once every 3 to 5 days, 3 times in a row, aphids could be eliminated. ②: 0.5kg of cigarette stick, 0.25kg of quicklime, 1015L of water, soaking for one day and night, filtering and removing dregs for spray control, the effect is good. Leaf miner

[damage status] the larvae of leaf miner sneaked into the tender leaves and shoots of camellia to eat food. The damage began in May, and the pest became more serious in June, and the pest was the most serious from July to September. Translucent markings appeared on the epidermis of the young leaves, and white or translucent bubbles appeared on the epidermis of the killed shoots. Camellia plants grow poorly and their leaves are twisted and shedding.

[control method] ① can be controlled by 5000 times of fenvalerate and 1000 times of omethoate, and sprayed 3 times before and after the occurrence of insect pests. If there are nymphs in ② family potted camellias, they can be killed by artificial capture. Tea poison moth

The main cause of this disease and insect pest is that the larvae eat the new shoots at the top of camellias, resulting in the death of the new shoots.

[control methods]: chemical control was carried out in time from larval hatching (mid-late July) to overwintering twigs (October). The medicament can be 40% dimethoate, 80% dichlorvos emulsion 1500 times, 2.5% Uranus EC 3000 times and 50% Batan powder 1500 times. When spraying, be sure to spray the back of the leaves with insect spots. Leaf roll moth

[check out the "tea poison moth" for control methods]

Sunburn

The daily burns of camellias are mainly caused by the sunburn of young leaves when they encounter high temperature during the growth period. If only a few leaves appear this situation will not affect the growth of camellias. Once found, it should be shaded from the sun.

Blind stink bug

The blind bugs are also called blind bugs. Cotton blind bugs occur for five generations a year. The main species are green bugs, three-point blind bugs, alfalfa bugs and so on, of which green bugs are the most harmful. It began to harm the tender leaves of camellias in May, and the damage was severe from June to August. It flew back to the overwintering site in mid-late September to lay eggs and overwintered. The blind bug elephant likes yin and dampness, is afraid of light, and goes out at night. The harm is serious in the years with more rainfall and humidity from June to August, but less in the dry years.

1. The liquid must be sprayed on both sides of the camellia leaves, especially the damaged leaves, the upper and lower stems and the cracks around the ground. 2. The best time for prevention and control is from 5 to 7 p.m., prevention and control drugs should be used in rotation, and when spraying, they should first hit the periphery, turn the enclosure to fight in, concentrate annihilation, and prevent migration; 2, the prevention and control agents should choose internal absorption, fumigation, contact, or compound dosage forms. Such as Mara phoxim, cyfluthrin, cypermethrin, chlorpyrifos, phoxim, cyhalothrin and so on. Small green leafhopper

Small green leafhopper adults long 3.3-3.7mm, yellowish green to green, compound eyes grayish brown to dark brown, no monocular, antennae bristly, the end of black. Forechest dorsal plate, small shield light bright green, often with white spots. The front wing is translucent, slightly leathery, yellowish white, with light green edges around it. Hindwing transparent membranous, each foot tibia end below the light green, brown claws; tarsus 3; hindfoot jumping foot. The color of the abdominal dorsal plate is darker than that of the web, and the end is light green. The back of the head is slightly shorter, protruding forward, the beak is brownish, and the base is green. The egg is long oval, slightly curved, long diameter 0.6mm, short diameter 0.15mm, milky white. The length of nymph is 2.5-3.5mm, which is similar to that of adult.

When the adult and nymph sucked juice, the yellow and white spots of the injured leaves gradually expanded into pieces, and when the whole leaf was serious, the whole leaf was pale and early. It has 6 generations each year and overwinters as adults in deciduous leaves, weeds or low green plants. The next spring peach, plum and apricot sprouted and stung, flew to the tree to suck juice, mated and laid eggs after feeding, and the eggs were mostly laid in the new shoots or the main veins of leaves. The egg stage is 20 days, the nymph stage is 10-20 days, the life span of non-overwintering adults is 30 days, and the completion of a generation is 40-50 days. Generations overlap due to irregular occurrence periods. The number of insect population increased in June, and it was the most from August to September. The last generation of adults overwintered after autumn. Adults and nymphs like to be active during the day, sucking juice or perching on the back of the leaves. The adults are good at jumping and can be spread by wind. The ten-day average temperature is 15 ℃ and 25 ℃ is suitable for its growth and development, and the population density decreases in the weather of more than 28 min and continuous rain. Control methods (1) remove fallen leaves and weeds before adult stinging, and reduce the source of overwintering insects. (2) after the adults of the overwintering generation moved in During the peak incubation period, each generation of nymphs were promptly sprayed with 20% chlorpromaxur EC 800 times or 25% aldicarb EC 600 times 800 times, 20% propoxur EC 400 times, 50% malathion EC 1500 colors 2000 times, 20% chrysanthemum EC 2000 times, 2.5% dichlorvos or kungfu EC, 50% aldicarb ultrafine wettable powder 3000 liter 4000 times, 10% imidacloprid wettable powder 2500 times, 20% paracetamol EC 1000 times, 40% methophos EC 1500 times, 2.5% bod EC 2000 times, 35% Saidan EC 2000-3000 times All of them can get better results.