Appendix 1: Invasion of new biotypes of Bemisia tabaci Foreign scholars believe that, since the 1990s, major outbreaks of Bemisia tabaci in the world have been related to the emergence and invasion of new biotypes. Since 1997, the number of populations of B. tabaci has increased significantly in northern and southern parts of the country. Until 2000, China, Hebei, Beijing, and Xinjiang reported the outbreak of B. tabaci. After identification by experts, it was confirmed that the population was mainly a new type of biotype that was invaded from abroad, that is, B-type whitefly. Adopting the internationally-accepted method of “silver zucchini silver leaf reaction†[Biological evaluation of multi-pointed and multiple collected helminths showed that the population of Bemisia tabaci which has been outbreak in southern Zhejiang in recent years is mainly B biotype. Best Chinese Whiskey,Chinese Rice Whiskey,Chinese Sorghum Whiskey,Chinese Scotch Whiskey Shan Dong Kao Shang wine industry Co.,Ltd , https://www.ksbaijiu.com
Bemisia tabaci (Gennadius) is native to tropical and subtropical regions and has become a worldwide disastrous pest. According to foreign reports, the host range of Bemisia tabaci is very extensive, and it can damage more than 500 species of plants in 74 families. The population of solanaceous vegetables, melons, beans, broccoli, cabbage, Chinese cabbage, etc., has increased dramatically. Up to tens of heads of single-leaved adults, hundreds of them, even more than one thousand, crop failure in some areas due to poor or poor control of the situation. In the past, no crops such as cauliflower, cabbage, Chinese cabbage, cowpea, and green beans, which were damaged or rarely victimized, have been harmed in a large area. The scope of damage has affected almost all the main vegetables except onions and garlic, especially the greenhouses. weight.
Hazardous characteristics: In addition to directly inhaling and harming crops, the worms cause plants to decline, yellow leaves and fall off. Adult nymphs can also secrete honeydew to induce coal pollution, causing branches, leaves and fruit to appear black, and the quality and quality of crops are seriously reduced. At the same time, it also spreads a variety of extremely harmful plant viruses. For a long time, Bemisia tabaci in some areas is only a minor pest that has not been watched, but in recent years, the insect has emerged as a sudden outbreak. Serious damage.
Life history: Bemisia tabaci can not naturally overwinter in open field plants in the North. Most of them use winter locusts to cover winter crops in greenhouses and other sheltered crops. In some areas, there is no overwintering phenomenon in greenhouse crops. Even in the cold January and Spring Festival, they can still be seen. To a large number of adult eclosion and the slow development of the various insect states. The worm began to transfer to greenhouses at about 12°C in mid-to late October of Sanmenxia, ​​and it was allowed to multiply during winter. Adults and nymphs can be transmitted through vegetable colonization and insect transfer. Around mid-April the following year, adults began to move outside the shed. From July to August, the outbreak of nymphs harmed. At the end of September and early October, as the temperature dropped, some adults migrated to greenhouses, and the number of open mouth populations drastically decreased, completing the annual cycle.
Bemisia tabaci was the main source of insects in the spring of the following year, occurring in the 8th to 12th generation in one year, and in the overwintering stage of crops such as vegetables and flowers cultivated in protected areas such as greenhouses. In most areas, overwintering crops in spring protected crops have become adults, continue to grow on the protected crops, reproduce, and damage. After a warmer temperature, some whiteflies pass through the transplanting with insects and adults. Move to open field crops to reproduce, harm, and expand the population. After entering the summer, the whiteflies on the protected crops are gradually relocated to open field crops for breeding and endangerment, until the whiteflies on the open crops in the late autumn are gradually reverted to the protected crops until the wintering; in some areas Bemisia tabaci can be subcultured and propagated throughout the year. Its migration pathway is the same as above. According to the survey, in the open field crops, the main period of Bemisia tabaci in 1 year extends from midsummer to late autumn; in protected crops, its main damage period is late spring and late autumn.
Control methods
1. Agricultural control and agricultural control are important links in controlling the occurrence of Bemisia tabaci. It is necessary to focus on the following points: First, to cultivate insect-free and strong seedlings, the greenhouses used for nursery should be separated from the production greenhouses, and attention should be paid to removing the remaining adult insects with tobacco smoke agents before and after transplanting. The best way to grow seedlings in the open field is to use a small bow shed to cover the pests; the second is to remove the weeds and debris from the field in a timely manner in the production process and to change the defoliation in order to reduce the source of insects; the third is to avoid Solanaceae and Cucurbitaceae as much as possible. , pods, and cruciferous vegetables are connected and connected in succession, and boring and crop rotation of onion, garlic, leeks, lettuce, celery, spinach, and other whitefly are not favored in re-emergence areas to reduce population development. the amount. In particular, autumn and winter crop rotations have a significant effect on lowering the overwintering base number and reducing the occurrence of damage in the coming year.
2. Physical Control Physical control is one of the effective measures to control Bemisia tabaci. One is to use the characteristics of Bemisia tabaci against orange yellow with a strong tendency to make "yellow armyworm board" (abbreviated as yellow board) to monitor and control Bemisia tabaci [1,4]. According to the test of Wenzhou Academy of Agricultural Sciences, several 20cm25cm experimental orange viscose boards were hung on the top of tomato replants in the Bemisia tabaci. The 14-day inspection showed that the average amount of adults trapped on a single day It was 192.2 heads and the highest 1378 heads. At present, the “yellow plates†used in China are mostly coated with on-site coated No. 10 motor oil and directly hung and trapped on yellow cardboard [4], or the yellow plastic plates are directly hung and seduce after being glued. There are still inconveniences, sticky hands, and environmental protection. Other issues; The price of a small number of Taiwanese commercialized “yellow plates†is more expensive. In recent years, the Institute of Ecological Environment of Wenzhou Academy of Agricultural Sciences has developed a new type of paper-friendly “Mythimna sebum†product to overcome these problems and has been well-received after preliminary promotion. The second is to use insect nets to cover cultivation to prevent the invasion of tobacco whitefly. Practice has proved that the better method is: winter and spring greenhouse cultivation of vegetables and other crops can be set around the door and door entrance 40 mesh insect net in the film inside, to prevent the invasion of pests when the membrane is ventilated; summer and autumn can be used insect nets canopy network coverage Cultivation or top film skirt net cultivation.
3. Biological control Given the limited conditions and practical considerations, the author believes that in addition to the direct use of biological pesticides, biological control at this stage should focus on the protection and use of natural natural enemies in the field, in which long-term use of natural enemies to kill small The selective pesticides and other measures to protect the natural enemies in the field, gradually restore the ecological balance between the benefits and the damage, and give full play to the natural control role of natural enemies. Which type of pesticide is specifically applied can be selected according to the test observation or relevant data. Where conditions permit, crops cultivated in greenhouses can be introduced into natural enemies such as Encarsia formosa, Eretmocerus sp., and Verticillium lecanii.
4. Chemical control? The body surface of B. tabaci has been waxy, and it breeds quickly and has serious overlapping generations. It is easy to produce drug resistance, and it brings many difficulties to chemical control. Therefore, scientific drug use is very important. The first is to choose the right counterparts, according to Wenzhou City, Taizhou City Academy of Agricultural Sciences field trials, 70% Amy Le can disperse granules, 25% Aktai dispersible granules, 3.5% Ruidan EC, 5% sharp Suspension concentrate, 99.1% paraquat oil emulsion, 20% acetamiprid soluble liquid, 20% bisilicon soluble liquid, 20% acetamiprid soluble liquid, 10% imidacloprid wettable powder, 1.8% ivermectin Emulsifiable concentrates, 25% sedoxinone WP, 0.4% matrine wettable powder and other pesticides have good efficacy against B. tabaci in most regions. Among them, the total control effect of adult insects to insects can be controlled within 150 days after spraying, 150 times for fipronil, 1500 times for fipronil, 2000 times for Bixi, 5,000 for Acetate, 2000 times for acetamiprid, and 1200 times for Diltiazem. Above 90%-95%; Second, pay attention to the rotation of pesticides of different types and different mechanisms of action. Generally, the use of similar pesticides per crop should not be more than 2 times, and pesticides that are resistant to drug resistance, such as mineral oil, should be promoted. The third is to use drugs early in the development of whitefungus, and to eliminate the blind increase in the amount of application and application times per unit area; four is to pay attention to the application of technology, such as spraying the leaves on the back, spray the amount of liquid; with Akte Irrigation treatment takes full control of seedling stage damage.
Appendix 2: Shape Recognition of Bemisia tabaci (Wood9818 Posted at 2005-3-26 13:39:00)
First, the morphological characteristics
The whitefly pest is an anamorphic insect. The nymph stage basically passes through the third instar. After the third instar nymph molting, it becomes a "flea" with exogenous wing buds. The "fungus" is transformed into the underside of the third instar nymph and the In the hardened skin, this shell is called "clam shell." The classification of whiteflies is basically based on the characteristics of the fourth instar larvae, ie, "shellfish", unlike other groups, which are mainly based on adult characteristics. This is the particularity of the whiteflies classification. This is because the characteristics of the oyster shell are very distinct and the morphological difference at the adult stage is not obvious. The main classification features of the various parts of the clam shell are now described as follows: The clam shell is slightly elliptical or nearly circular, but also has irregular shapes. Before the transverse joint, the head and thorax were followed by the abdomen. Sometimes there are various shapes of indentations on the edge of the shell. From the back of the clam shell, it can be seen that there is a sub-body edge between the body edge and the peripheral parallel sub-line. Within the sub-line is the back panel. There is a vasiform orifice behind the back panel area. There is an operculum on the outside of the back panel. There is a lingula under the flap. The lingula is different for each kind of flap and is covered by the flap. There are also those who extend beyond the flap. The anus is opened in the tubular hole, and the anus can secrete a large amount of honey juice and accumulate on the tongue. Therefore, there is a misunderstanding that the tongue has the function of secreting honey juice. The tubular hole in the clam shell is one of the features of the classification. On the back of the oyster shell are creatures with thorns, bristles or papillae. There are also smooth, unsqueezed and surface wrinkles.
?? The basic characteristics of the tobacco powder oyster shell, inter-species variation, "the same species with numerous different forms, each form is associated with different hosts." On the leaves of hairy plants, most of the clam shells have bristles on the back; on the leaves of smooth plants, most of the clam shells do not have back bristles during development, and there are also differences in size, shape, and irregularity in the morphology of the clam shells. In terms of classification, false lice are an important classification basis. Its main features are: tubular hole triangles, longer than the width, the rear of the hole has a small nodular protrusion, the inner edge of the hole has irregular teeth. The semi-circular cover covers approximately one-half of the hole, the tongue protrudes significantly beyond the flap and is long spoon-shaped with two bristles at the end. The abdominal sulcus is clear from the tubular hole leading to the end of the abdomen and its width is similar.
2. B. tabaci (Gennadius) and B. afer (Priesner & Hosny)
The two species of whiteflies belong to Bemisia. The main characteristics of this species are oval, pale, and brown. Tracheolar regions sometimes differentiate into crowns. The front and rear side edge bristles exist. Dish-shaped hole long triangle, tongue-shaped spoon-like. The back area has a series of bristles. Some kinds of features vary greatly.
B. afer (Priesner & Hosny): The clam shell is pale, with few waxy exudates at the periphery; oval, slightly recessed at the rear tail valve. A number of short lines extend from the edge to the inside. It is 1082-1320 μ long and 790-957 μ wide.
The edge is generally more regular and the edge teeth are irregular. The crown of the chest valve differentiates into many teeth, which are larger than the marginal teeth and have a high degree of hardening. Valves slightly contract. Front and rear side edge bristle pole more?
?? Horizontal chin sutures and chest sutures do not reach the edge of the oyster shell. The number and length of the bristles, the number and size of the knobs, and their position are quite variable, but generally the bristles exist on the head, the first section of the abdomen, and the bases of the dish-like holes. The dish-shaped hole is long and elliptic, with a pointed tip, a slightly curved side edge and lateral ridges, and a transverse ridge at the end. The cover plate is subcircular, wider than long, and the base is curled up, covering one-third of the hole. The tongue is long, spatula-shaped, and the top is pointed and a pair of bristles are born.
?? Bemisia tabaci (Gennadius): Oyster shell is generally oval, sometimes concave edge, showing asymmetrical morphology. The sub-region is not separated from the back area, and the marginal teeth are irregular. The carcass on the smooth hairless leaves does not have long bristles on the back, while on hairy leaves, the back has up to 7 bristles, sometimes with long bristles. Even on the same blade, the shape of the oyster shell is not the same. The color of the clam shell can vary from colorless to brown due to the season and location on the host. Therefore, this species exhibits a great host-related morphological variation and should be carefully identified.
This species is a well-known transmission medium that can spread virus in some crops, which is more serious than direct damage.
?? Distribution: the United States, Europe, Africa, Asia, Australia and other continents. China Guangdong, Guangxi, Hainan, Fujian, Yunnan, Zhejiang, Jiangxi, Hubei, Sichuan, Taiwan, Shanghai, Hunan, Shaanxi, Beijing, Henan, Hebei, Tianjin, Shanxi and Xinjiang. In 2000, the species was seriously affected in northern China. As the survey began, its distribution area will continue to expand.
?? The above two kinds of white powder often occur mixed, the shape is very similar and difficult to distinguish. The distinguishing features of the two are as follows: (1) B. afer in Africa is larger, B. tabaci is smaller in clam; (2) B. afer is more regular in shape, generally oblong, with ends and chest valves Slightly concave; B. tabaci irregularly shaped hairy leaves, sometimes sharply concave; (3) B. afer's chest, abdomen valve crown teeth are larger than the edge teeth, hardening degree is high, and B. afer. Tabaci's valve crown hardening is less pronounced; (4) B. afer has a horizontal ridge near the end of the dish-shaped hole, whereas B. tabaci does not.
Third, the whitefly and greenhouse whitefly T. vaporariorum (Westwood)
The Greenhouse Whitefly belongs to the genus Trialeurodes. The main characteristic of this genus is that the pod is pale, surrounded by wax layers and wax edges. The most striking feature is that the sub-edges have wax holes, heart-shaped pot-shaped holes, and lingual trilobular. The main features are: oval shell, white. It is 754 μ long and 480 μ wide. The back panel area is not separated from the sub-margin; there are many mastoids in the sub-marginal area in a circle, the number of mastoids exceeds 60, of which 6 pairs or 5 pairs are larger, 2 pairs are on the head, 1 pair is on the front thoracic section , 1 pair behind the transverse joint, 1 pair in the sixth abdominal segment (sometimes missing), and 1 pair in the eighth abdominal segment. There is a wax gland secretion hole distribution in the inner mastoid ring. The back panel has 4 or 3 pairs of mastoids, which are much larger than those in the subarachnoid area. One pair is on the sides of the head, one pair is on the chest, one pair is on the third abdominal section, and one pair is on the fourth abdominal section (sometimes lack).
Dish-shaped hole heart-shaped, with irregular teeth on the side of the inner edge. One-half of the lid cover hole. Tongue-shaped cloverleaf with two bristles.