What are the diseases and insect pests of tea?

What are the diseases and insect pests of tea? How to prevent and cure it? Please guide the following common tea diseases and insect pests: 1. Tea small green leafhopper: the insect mainly uses adults and nymphs to suck the juice of the tender shoots of tea trees, and the female adults lay eggs in the tender shoots and stems, which hinders the growth of tea trees, curls and hardens the damaged buds and leaves. Red-brown scorched leaf tip and leaf edge. Thirteen generations of the insect occurred in the low mountain tea area, and the peak damage period was from May to June and from September to October, while in the alpine tea area, the insect occurred for 9 generations and the peak damage period was from July to September. Overwintering with adults on tea plants, legumes and weeds. Most of the adults lay eggs in the tender stem between the second and third leaves of the new shoot. Prevention and control methods: (1) strengthening the management of tea garden, removing weeds and picking in batches in time can reduce insect eggs, worsen nutrition and reproductive conditions, and reduce harm. (2) serious tea gardens with large overwintering insect population should be sprayed 1000 times of phoxim or malathion from late November to mid-March to eliminate the overwintering insect source. (3) according to the forecast of the insect situation in the picking season, the biological pesticide Tianba 1000 times or 80% dichlorvos 2000 times or 98% Batan 1000 Murray 1500 times was selected before the nymph peak. 2. Tea mites: tea mites are an important pest second only to leafhoppers in tea trees. Because of their small size, they are generally difficult to detect with the naked eye and can only be observed under a 10-fold magnifying microscope. The main occurrence species in our city are tea orange gall mite, tea gall mite, tea short beard mite, coffee small claw mite and side polyphagous tarsal mite. 3. Tea orange gall mite: the occurrence of tea orange gall mite is more common in our city. Adult and nymph mites feed on adult leaves and tender leaf juice, resulting in yellowish green leaves, reddish brown main veins, loss of luster, brown fine markings on the back of leaves and atrophy of bud leaves. The adult mites are yellow or orange-red, like carrots, with two pairs at the front of the body, and the young and nymph are yellowish to light orange. The insect occurs for more than 20 generations in a year, and the insect population is mainly distributed on the upper mature leaves and tender bud leaves. In the environment of high temperature, drought, heavy rainfall and long rain period, the number of insects in the tea garden is small and the harm is light. There are two obvious peaks in the whole year, the first is from May to June, and the second usually occurs after the high temperature and drought period. Control method: after the end of ① autumn tea, spray Baume 0.5 degree stone sulfur mixture before late November to reduce the population number of overwintering insects. ② can reduce the number of insects by picking several times in batches. Before the peak, ③ was sprayed with 20% dicarboxylic acid or 15% mifenac 2000-3000 times or 25% buprofezin 800muri 1000 times. 4. Tetranychus Tetranychus: also known as Tetranychus polyphagus and Tetranychus Tetranychus. Adult and nymph mites inhabit the back of tea bud leaves to suck juice, and the affected leaves appear ferruginous color, hardening and thickening, and the leaf tip is twisted. The bud leaves atrophied. The mite produced 30 generations of 20 Mel in a year, with female adult mites in residual bud leaves, scales and petioles. Overwintering on sewing holes and weeds. The climate of high temperature and drought is favorable for its occurrence. Generally speaking, the occurrence of summer and autumn tea is more serious. Control method: refer to tea orange gall mite. 5. Tea gall mite: it mainly harms adult leaves and old leaves, the damaged leaves lose luster and show bronze color, the leaves are covered with white dusty waxy molting along the veins, the leaves are brittle and easy to crack, and a large number of fallen leaves are serious. The mite occurred for more than 10 generations a year, and the adult mites overwintered on the back of tea leaves. The season of high temperature and drought is favorable to occur, and the peak occurs from July to October in the whole year. Control method: refer to tea orange gall mite, but multiple picking in batches is ineffective to it. 6. Tea short beard mites: adult and nymph mites are sucked into leaves or old leaf sap, resulting in loss of luster of leaves, purple patches on the back of leaves, browning of main veins and petioles, mildew and rot in the later stage, causing a large number of fallen leaves. The mite occurs for about 10 generations a year, mainly as female adult mites overwintering in the root neck of 1cm tea trees in the soil, and a few in the back of leaves, axillary buds and fallen leaves. Most of the tea gardens are female mites, which are parthenogenetic and mainly inhabit the back of leaves. In the whole year, the damage is serious in the high temperature and dry season from July to September. Prevention and control methods: (1) do a good job of drought resistance in tea garden, remove fallen leaves and weeds, strengthen management, enhance tree potential and improve stress resistance. (2) after the end of autumn tea, pest mites were sprayed with Baumei 0.3 / 0.4 degree stone sulfur mixture before overwintering. (3) before the peak of the occurrence of harmful mites, 20% dicarboxylic acid or 15% mifenapine 2000, 3000 times or 73% mites, 2000 times or 25% quinathion 1000, 000, 500 times, were sprayed for control. 7. Coffee small claw mite: the mite is harmful to the leaves by adult nymphs, and the damaged leaves turn red, and then show dark red spots and lose their luster. When the dew is not dry, a layer of fine spider silk can be seen on the leaf surface, and there are many small red spots stained with blood on the leaves of hand-pinched mites, red worms crawling on the leaves, and many white molting shells and egg shells near the mite body. There are 20 generations of 10 / 10 / 20 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 10 / 20 / 20 generations, with generations overlapping. Multi-inhabiting foliar hazard. The eggs are scattered on the front of the leaf and mostly on both sides of the main and lateral veins and depressions. The harm is serious in the early stage, autumn and winter. Control method: refer to tea short beard mite. 8. Tea aphids: tea aphids are common in our city, but they are easy to control pests. Tea aphids often gather on the back of the new shoots, and the first and second leaves under the bud are the most, and the oral needles are pierced into the tender leaf tissue from time to time, causing the bud leaves to atrophy, stop elongation, and even wither the shoots. Its excreta "honeydew" not only pollutes the tender shoots, but also can induce coal disease. It occurs more than 20 generations a year, all overwintering with eggs or wingless aphids on the back of leaves, the insect population is mostly on the tender leaves in the middle and lower part of tea bushes in early spring, and gradually shifts to the middle and upper bud shoots in warm spring, less in hot summer, mostly in the lower part, and more in the middle bud shoot above in autumn. The methods of prevention and control are as follows: (1) picking in batches in time. (2) the medicament is usually sprayed with 2000 times of 40% dimethoate, 50% phoxim and 80% dichlorvos, especially to wet the back of the leaves. 9. Black thorn whitefly: serious harm in some tea areas of our city. The larvae gathered on the back of leaves, fixed sucking juice and excreting "honeydew" to induce the occurrence of soot disease. The injured branches and leaves blackened, and in serious cases, a large number of fallen leaves, resulting in the weakening of the tree, affecting the yield and quality of tea. The insect has four generations a year, overwintering with mature larvae on the back of the leaves, pupating in March of the following year, and Eclosion in the first and middle of April. The larval occurrence periods of each generation are from late April to late June, from late June to early July, from mid-July to early August and from early October to December, respectively. Adults lay eggs on the back of leaves, and after the newly hatched nymphs crawl, they do harm to fixed sucking. Prevention and control methods: (1) strengthen the management of tea garden: combine pruning, table cutting and weeding to improve the ventilation and light transmission condition of tea garden and restrain its occurrence. (2) Biological control: spraying 0.5 kg / mu of Weber spore fungus powder or hanging fungus branches, that is, hanging Weber spores on tea bushes around the tea bushes, 5 times per square meter for 10 times. (3) Chemical control: according to the forecast of the insect situation, spray 25% chlorpromazine 800 times or 25% Uranus 1000 times or 50% phoxim 1000 times during the peak egg incubation period, be sure to wet the back of the leaves. 10. Tea weevil: also known as tea small black weevil. The harm of some tea areas in our city is serious. The larvae feed on the whisker root in the soil and mainly bite the leaves with adults, resulting in an arc at the edge of the leaves. When it is serious, the residual leaves of the whole garden are bald, which has a great influence on the yield and quality of tea. One generation a year, the larvae overwintered in the soil under the tea canopy, pupated in late March, emerged and unearthed in early April, and the peak period of adult damage was from May to June. Adults have the nature of false death and fall to the ground when alarmed. Control methods: (1) ploughing and loosening the soil can kill larvae and pupae. (2) make use of the false death of adults, spread plastic film on the ground, and then vibrate and concentrate on elimination. (3) sprinkle Beauveria bassiana 871 powder before the adult is unearthed, mix the fine soil with 1ml / mu bacterial powder and apply it to the soil. (4) spraying 2.5% Uranus 800 times or 98% Batan 800 times before the peak of adult unearthed or mixed with 871 bacterial powder 0.5ml 1.0kg / mu. 11. Tea leaf moth: commonly known as "leafworm" or "curly worm", the larvae roll up tender shoots and new leaves or bond several leaves into bracts, as many as 10 leaves, in which the larvae lurk to feed. In serious cases, the quality and yield of tea are greatly reduced. The insect has 6 generations in a year and overwinters as mature larvae in the bud. The initial stages of each generation of larvae are usually in late March, late May, late July, early August, early September and early November. The generations overlap and the larvae have six instars. The adults have phototaxis, and the eggs are clustered on the leaf surface. Prevention and control methods: (1) remove egg mass and insect bud casually, and pay attention to protect parasitic wasps. (2) Light traps and kills adults. (3) to master the spraying control of 1st and 2nd instar larvae. You can choose 1000 times 80% dichlorvos or 2.5% Uranus or 25% quinathion. 12. Tea branch cockroach moth: also known as borer, it is distributed in all tea areas of our city. The larvae often eat the branches, the bud leaves on the branches stop elongating at the initial stage, and all the branches and leaves above the hollow part of the branches die. The insect occurs in one generation in a year and overwinters as larvae in the branches. The pupation began in late March, the peak period of pupation in late April, and the peak period of adult pupation in the middle and last ten days of May. Adults lay eggs at the second and third leaf nodes of tender shoots. After the larvae ate the tender shoots for a few days, the upper bud leaves withered, entered the branches after the third instar, and finally ate near the ground. The decay path is relatively straight, biting through the near circular excretory hole to the shade at a certain distance, accumulating catchy debris at the bottom of the hole, and dark yellow short columnar fecal particles scattered on the nearby leaves or on the ground. Control methods: (1) in the peak period of adult Eclosion, light traps and kills adults. (2) after the end of autumn tea, cut off the insect branches and kill the larvae from 5 inches below the lowest excretory hole. 13. Moss and lichen: Moss is a higher green plant that lives in a damp place. Lichen is a symbiosis of bacteria and algae, which can be divided into leaf-shaped, shell-shaped and branched lichens according to their shape, which can spread upward from the roots and stems of tea trees. as a result, the tea tree bark is brown and rotten, which seriously affects the normal growth and development. In the spring rainy or plum rain season, the fastest growth, in the hot summer and cold winter, stop growing. Prevention and control methods: (1) strengthen field management, timely ploughing and weeding, idle season, can be scraped with bamboo and other tools after rain and casually cleared out of the garden. Keep the tea garden clean, fertilize reasonably and cultivate exuberant trees. (2) spray with 1% lime equivalent Bordeaux solution, the effect can reach 90%, boil and concentrate with plant ash leaching solution in winter, it also has a very good effect. Second, what are the main diseases of tea trees? How to prevent and cure tea white spot scientifically? 1. Tea white spot disease: (1) symptoms: mainly harmful to young leaves and shoots. The large brown dot of the primary needle, then gradually enlarged into a small round spot, less than 2 mm in diameter, sunken in the center, grayish white, surrounded by brown protuberant lines. In the later stage, the disease spot is scattered with small black spots, and there are more than a hundred disease spots on a tender leaf. (2) incidence regularity: the disease belongs to the disease of low temperature and high humidity. The mycelium overwintered on the diseased branches and leaves. In the following spring, when the temperature rose above 10 ℃, conidia formed on the disease spot under the condition of high humidity, which were transmitted by wind and rain and invaded the young shoots. Low temperature and rainy spring tea season is the most suitable for spore formation and disease epidemic. High mountains and young tea gardens are prone to disease. The disease is easy to occur in barren soil, partial application of N fertilizer and improper management. (3) Control methods: strengthen the management of ①, increase the application of phosphorus and potassium fertilizer, enhance the tree potential and improve the disease resistance. ② can be protected by spraying 70% methyl topiramate or 50% carbendazim 1000 times in the budding stage of spring tea and sprayed again every 7 days or so. 2. Tea cake disease, also known as tea swelling disease, often occurs in high-altitude tea areas, harming tender leaves, shoots and petioles, and the tea taste of diseased leaves is bitter and fragile. (1) symptoms: light yellow water-stained spots appeared on the initial leaves, and then gradually expanded into yellowish brown spots, with obvious edges, sunken on the front, cake-like protuberances on the back, gray-white powder on the back, and then turned to dark brown ulcer spots. (2) the law of disease: overwintering or summer with mycelium in diseased leaves. The environment with a temperature of 15 ℃ and a relative humidity of more than 85% is prone to the disease. The harm is usually serious from March to May and from September to October. The shady side of the sloping tea garden is more susceptible to the disease than the sunny side, extensive management, weeds, improper fertilization, shaded tea garden is also easy to occur. (3) Prevention and control methods: ① tea cake disease can be transmitted through tea seedlings, so quarantine should be strengthened. ② weeds frequently, proper pruning between tea gardens, promote ventilation and light penetration, can reduce the incidence of disease. ③ application of phosphorus and potassium fertilizer to improve disease resistance, removal of diseased leaves in winter or early spring combined with tea garden management can effectively reduce the number of pathogens. ④ picking tea garden was sprayed 1000 times with 70% methyl topiramate or 20% trimethoprim at the initial stage of the disease, and 10 Mel was sprayed again in 15 days. 3. ⑴ symptoms of tea anthracnose: it mainly harms adult leaves or old leaves, and the disease spots are mostly produced from the leaf edge or leaf tip, which are initially water-stained, dark green and round, then gradually enlarged or irregular, yellowish brown or light brown in color, and finally turn grayish white, with small black spots scattered above. There is no wheel pattern on the disease spot, and there is a yellowish-brown bulge line on the edge, which has a clear boundary with the healthy part. (2) Disease regularity: the mycelium overwintered in diseased leaves, and spores were formed the following year when the temperature rose to 20 ℃ and the relative humidity was more than 80%, which was transmitted by Rain Water. Humidity 25 ℃ 27 min, high humidity condition is the most favorable for the disease. The plum rain season and autumn rain season are the most popular in the whole year. Cutting tea garden and Taiwan-cut tea garden have young leaves and high water content, which is beneficial to the disease. The disease was also serious in tea garden with partial application of N fertilizer. (3) Control methods: ① should strengthen the management of tea garden, increase the application of P and K fertilizer, and improve the disease resistance of tea trees. At the initial stage of the onset of ②, 70% thiophanate methyl was sprayed 1500 times or chlorothalonil 500 times. 4. Tea cloud leaf blight mainly harms old leaves, and can also occur on tender leaves, fruits and branches. The disease spot mostly occurs in the leaf tip, leaf edge, showing a semicircular or irregular shape, initially yellowish brown, water stains, and then turn brown, on which there are wavy wheel patterns, similar to moire. Finally, the disease spot turns gray-white from the center to the outside, and the upper gray-black particles are arranged along the wheel pattern. The disease is most prevalent under the condition of high temperature (more than 20 ℃) and high humidity (relative humidity more than 80%). Trees are weak and poorly managed, and tea gardens that suffer from frost and insect pests are also seriously affected. Prevention and treatment: refer to tea anthracnose. 5. Tea ring spot disease occurs more frequently in adult leaves and old leaves, first producing yellow-green spots from the leaf tip and leaf edge, and then gradually expanding into round, semicircular or irregular disease spots. The disease spot is brown, there are obvious concentric round wheel lines, and in the later stage, the center becomes gray-white, the thick black particles are arranged in a ring along the wheel pattern, and there are often brown protuberant lines on the edge of the disease spot. The pathogen invades the tea tree tissue from the wound to produce new disease spots, which are more common in summer and autumn with high temperature and humidity. When pruning or machine-picking tea garden, the incidence of insect pests in tea garden is more serious. The disease is also serious in the tea garden with weak tree potential and poor drainage. Prevention and treatment: refer to tea anthracnose. 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