Species and occurrence regularity of Waxberry Diseases and insect pests and their Green Prevention and Control techniques in Zhejiang Province

Species and occurrence regularity of Waxberry Diseases and insect pests and their Green Prevention and Control techniques in Zhejiang Province

0 introduction

[research significance] Waxberry [Myrica rubra (Lour.) Sieb.et Zucc.] is a characteristic fruit in southern China, with sweet and sour fruit and unique flavor, so it enjoys a high reputation at home and abroad. Zhejiang Province is the main producing area of red bayberry in China. The planting area of red bayberry in the province is 86500 ha, accounting for about 1/3 of the whole country, with an annual output of about 500000 tons and an output value of 4.83 billion yuan. It ranks first in the output value of fruits in Zhejiang Province, and is the leading industry for farmers in Taizhou, Wenzhou, Ningbo, Lishui, Jinhua and other mountainous and semi-mountainous areas to get rich. In recent years, with the rapid development of Zhejiang bayberry industry, especially with the continuous expansion of Dongkui bayberry planting area, the occurrence of diseases and insect pests is becoming more and more serious, with heavy prevention and control tasks and great safety risks. Therefore, it is of great significance for ensuring the sustained and healthy development of bayberry industry and increasing farmers' income to find out the main diseases and insect pests and the law of occurrence and damage of Zhejiang bayberry, and put forward control countermeasures and green prevention and control technology. [previous research progress] up to now, there have been many studies on the main diseases and insect pests, occurrence regularity and control techniques of red bayberry in the main producing areas of Zhejiang Province. Wang Hongxiang et al. (1999), Gong Jieqiang and Wang Hongxiang (2002) reported that the main diseases of red bayberry in Taizhou City, Zhejiang Province were brown spot, cancer, red clothes, dry blight, branch rot and shoot blight. The main pests were shell insects, whitefly, paulownia inchworm, leaf roll moth, coir moth and termites. The reasons for the increase of diseases and insect pests were analyzed, and the corresponding control measures were put forward. However, it has not gone deep into the specific disease and insect species investigation and green prevention and control technology. Liu Yougao (2006) reported the occurrence characteristics and control techniques of diseases and insect pests such as bayberry cancer, brown spot, shell insects and moths in Wenzhou City, Zhejiang Province, but there is no systematic investigation and study on the species of other diseases and insect pests of Waxberry. Most of the chemicals introduced in chemical control are not registered in bayberry, so it is difficult to use drugs safely. Liu Gaoping et al. (2013) and Zou Xiuqin et al. (2015) reported simple net room cultivation and green control techniques of Dongkui red bayberry. Ren Haiying et al (2014) reported the occurrence and control of bayberry wilt and diamondback moth pests. [entry point of this study] from the general research situation, the investigation and research on the types and control techniques of bayberry diseases and insect pests in Zhejiang are still not systematic and in-depth, and the agricultural, biological, physical and chemical control measures are still lack of organic coordination and supporting, thus affecting the implementation of integrated control technology and the improvement of economic, social and ecological benefits. [key problems to be solved] the methods of systematic general survey and fixed-point monitoring, experimental research and demonstration were used to investigate the species, distribution and harm of the main diseases and insect pests of Waxberry in Zhejiang Province. to explore the green prevention and control technology and comprehensive management strategy of the main diseases and insect pests of red bayberry, so as to provide scientific basis for the prevention and control of bayberry pests.

1 materials and methods

1.1 investigation on the species of bayberry diseases and insect pests

From 2013 to 2016, 18 counties (cities and districts) in the main producing areas of red bayberry in southeastern Zhejiang, central Zhejiang and northwest Zhejiang were selected to investigate the red bayberry woodland in different areas, different age groups and different land conditions according to the planting and growth of red bayberry. The occurrence of bayberry diseases and insect pests was observed and recorded, the damage degree was recorded, the corresponding disease and insect specimens were collected and brought back to indoor identification, and the families, genera, species names and pathogens were determined. And refer to the relevant literature (Qi Xingjiang, 2014) to sort out and record the types of diseases and insect pests, and comprehensively analyze the regional distribution and damage degree.

1.2 dynamic monitoring of the occurrence and damage of major diseases and pests

On the basis of the general survey of diseases and insect pests, two varieties of Dongkui red bayberry and water chestnut were selected in the main producing areas of red bayberry, such as Huangyan District of Taizhou City. Three representative red bayberry orchards with an area of more than 1 ha were selected according to the production time of red bayberry. 10 bayberry plants were selected in each orchard. The occurrence and damage of major diseases such as bayberry flies, scale insects, leaf curl moth, brown spot and wilt and the population dynamics of pests were observed every 5 days. The living habits and environmental factors were observed, and the occurrence rules of diseases and insect pests were discussed and analyzed.

1.3 Integrated control experiment and demonstration application

The investigation experiments on cultivation management, fertilization, varieties, garden clearing in winter and the species and number of natural enemies of insect pests were carried out to evaluate and analyze the effects of agricultural and biological control on diseases and insect pests. In the red bayberry plantation in Huangyan District of Taizhou City, the experiment on the control of red bayberry flies was carried out 20, 30 and 45 days before bayberry harvest. The 2000-fold suspension of 60 g / L ethyl spinosad (produced by Dow Yinong Company) was carried out. 15 days before bayberry harvest, 20% sodium oleate soluble powder (produced by Zhejiang Ruili Biotechnology Co., Ltd.) and 25% thiazinone wettable powder (produced by Guangdong Foshan Daxing Biological Co., Ltd.) were tested 15 days before harvest. The experimental plot was randomly arranged with 2 bayberry trees per treatment plot, repeated 4 times, and surrounded by protective lines. The BP- 16 sprayer was used to spray 10 kg liquid in each district, and the blade was sprayed uniformly on both sides. The test method was carried out with reference to the guidelines for Pesticide Field efficacy Trials (2) (Institute for Pesticide Control, Ministry of Agriculture, 2004). The comparative experiment of hanging insect control net and not hanging insect control net was carried out 25 and 45 days before red bayberry harvest. For every 20 plants of red bayberry, 40 mesh net was hung for each plant. After hanging the net, pesticides were stopped in the whole orchard. After the red bayberry was ripe, 80 bayberry fruits were picked inside and outside the net. The number of larvae of single fruit fly was observed, and the control effects of hanging net on red bayberry flies at different times were compared. Integrated prevention and control strategies and green control techniques of bayberry diseases and insect pests were put forward in order to obtain higher economic, social and ecological benefits.

1.4 Statistical analysis

The test data were analyzed by DPS for analysis of variance and ISD (Tang Qiyi, 2013). The population reduction rate and correction control effect are calculated according to the following formula.

Reduction rate of insect population (%) = (pre-drug worm quantity-post-drug worm quantity) / pre-drug worm quantity × 100

Corrected control effect (%) = (treatment population reduction rate-control population reduction rate) / (100-control population reduction rate) × 100

2 results and analysis

2.1 species and occurrence of Diseases and insect pests of Waxberry in Zhejiang Province

The results of general survey and fixed-point monitoring (Table 1 and Table 2) showed that there were 69 species of common pests of red bayberry in Zhejiang Province, belonging to 5 orders and 29 families, and 22 common diseases of Myrica rubra, including 15 fungal diseases and 1 bacterial disease. there are 5 physiological diseases and 1 root knot nematode. The common and serious pests of red bayberry are shell insects, fruit flies, leaf rollers, inchworm, whitefly and aphids, and the more serious infectious diseases are bayberry brown spot, cancer, red clothes disease, white rot, wilt, tip blight and so on.

Table 1 species and occurrence degree of bayberry pests in Zhejiang Province

Table 1 M.rubra pests species,occurrence and damage degree in Zhejiang

+ + is severe occurrence, + + is moderate occurrence, and + is mild occurrence. Table 2 is the same

+ represented seriousdamage,++represented secondary seriousdamage,+ represented mild damage.The same was applied in Table 2

Table 2 Disease types and damage degree of Myrica rubra in Zhejiang Province

Table 2 M.rubra diseases,occurrence and damage degree in Zhejiang

2.2 occurrence regularity of main diseases and insect pests in Waxberry

2.2.1 main pests

2.2.1.1 the scale insect is an important pest on red bayberry, which sucks the juice of the host, weakening the growth of red bayberry and even withering the whole plant. There are many species of bayberry scale, including cypress oyster scale, oyster shield scale, camphor net shield scale, saw-bellied oyster shield scale, tea bran scale, clam scale, Taiwan molting scale, red brown shield scale, blow cotton scale, red wax scale, horned wax scale, mulberry scale and so on. Cypress oyster scale is dominant in Taizhou, Wenzhou and Lishui, Zhejiang Province.

The cypress oyster scale has two generations a year in Zhejiang, overwintering as fertilized female adults on branches or leaves, laying eggs in mid-April the following year, spawning peak from late April to early May, hatching nymphs in mid-May, hatching peak and nymph peak from late May to early June, mainly harming spring shoots of Myrica rubra. The male adult appeared in early June and reached the peak in early July. after mating with the female adult, the female adult laid eggs and began to hatch in the middle and late July. The second generation nymph was in the first ten days of August, which mainly damaged the summer shoots of red bayberry. The insect is distributed in all the main producing areas of red bayberry in Zhejiang Province. the female adults mainly harm the shoots of 1-3-year-old red bayberry and are clustered, while the male adults are mainly fixed on both sides of the midvein of the leaves, mainly harming the spring shoots of red bayberry. After the twigs are killed, the epidermis shrinks and dries up and dies after autumn; after being killed, the leaves are brown, the petioles become brittle, and the leaves fall in the early stage. After the branches were killed, the growth was sterile, the tree was weak, and a large number of fallen leaves and withered branches appeared. When the damage was serious, the whole plant of red bayberry withered and died, like burning.

2.2.1.2 Waxberry fruit fly is the main pest in the process of picking and storage of red bayberry. The female fruit fly lays eggs on the mature red bayberry fruit, and the larvae eat in the pulp after hatching, which makes the damaged fruit uneven, juice overflow and fruit drop, which seriously affects the yield and quality of red bayberry. Red bayberry flies in Zhejiang Province include Drosophila melanogaster, Drosophila melanogaster, Drosophila Takahashi and Drosophila melanogaster, among which Drosophila melanogaster and Drosophila melanogaster are the dominant species and sister species.

The adult of Drosophila melanogaster is small, with a body length of 3.0 to 4.0 mm, eggs of about 0.5 mm, and young maggots of milky white or yellowish white with a length of about 2.0 mm. The generations of red bayberry flies overlap in the field, so it is not easy to divide the algebra. Under the condition of temperature 20: 25 ℃ and humidity 65% 85%, the duration of a generation is 9-12 days. The worm laid eggs on the fruit and hatched into larvae at suitable temperature for 1-2 days. the larvae ate the pulp to cause rotten fruit and fruit drop, and the mature larvae pupated in the topsoil layer with the fruit falling to the ground. after 4-5 days of metamorphosis, the pupa finally broke out and became an adult, and the adult could lay eggs in about 2 hours. According to the observation in Taizhou and other places, it was found that before the middle of May, the red bayberry fruit was not mature and softened, the fruit could not become a food source, and the number of fruit flies was small; in the first and middle of June, as the red bayberry fruit matured continuously, the fruit fly had suitable food and appeared the peak period of damage. When the mature rate of red bayberry in the whole orchard reached 70% to 80%, the number of adults of fruit fly was high and the harm was serious. After fruit harvest in mid-July, due to a large number of fallen fruit and residual fruit on the tree, Drosophila once again appeared the peak period of adults, and then with the lack of food, the number of insects decreased. There were two peaks of red bayberry fruit fly population in Taizhou, Wenzhou and Lishui in the whole year, the first in mid-late June and the second in mid-July, causing white rot disease and causing great economic losses in mid-late June.

2.2.1.3 the main leaf roll moths harmful to Myrica rubra are small yellow leaf roll moth, small yellow leaf roll moth, brown belt long leaf roll moth and yellow leaf roll moth. The biological habits and occurrence patterns of these four species of leaf roll moths are similar, spinning and wrapping on the newly drawn young leaves at the top of the bayberry tree, in which the larvae roll up and eat the mesophyll sooner or later. When the larvae mature, they become cocoon and pupate, which makes the new shoots grow slowly and weakens; the larvae harm the young leaves and curl up into insect bags, and when serious, the new shoots are scorched. In Taizhou, Zhejiang and other places, there are mainly small yellow leaf rollers.

The small yellow leaf roll moth has 4-5 generations a year in Zhejiang. The 3rd-5th instar larvae overwintered in the rolled leaves and began to be active when the temperature rose to 7: 10 ℃ in the following spring. Except for the concentrated occurrence of the first generation, the generations of other generations often overlap, and the second generation larvae from mid-May to mid-June and the third to fourth generation larvae from early July to late August are the most harmful.

2.2.1.4 inchworm paulownia inchworm, also known as big inchworm and arched back worm, is a kind of gluttonous pest because the larva bites on the leaf. The damage of inchworm larvae was the most serious in cloudy days and in the evening. When the insect was rampant, all the leaves were eaten up and the branches in the bayberry orchard were bare, which seriously affected the yield. The insect has 2 or 3 generations a year in Zhejiang and overwinters as pupae in the rhizosphere topsoil. The first generation larvae occurred from mid-May to late June, the second generation larvae occurred from mid-July to late August, and the third generation larvae occurred from late September to mid-November.

2.2.1.5 the whitefly that harms bayberry whitefly includes bayberry whitefly, black thorn whitefly, Camellia oleifera black gum whitefly and citrus whitefly. Larvae cluster on the back of leaves to absorb juice and often secrete a large amount of honeydew and other excreta, thus inducing soot disease and affecting photosynthesis. resulting in withered branches and leaves, tree potential decline, yield decline. Red bayberry whitefly and spiny whitefly are the main damage in bayberry producing area of Zhejiang province.

The length of female adult, male adult and larva of red bayberry whitefly is about 1.2 mm, 0.80 mm and 0.25 mm respectively. There are 2 or 3 generations a year in Zhejiang, overwintering with larvae on the back of the leaves.

The whitefly whitefly occurs for 4 generations a year in Zhejiang, and the generation is irregular. The 2nd and 3rd instar larvae overwintered on the back of the leaves, generally pupated in the middle of March, and the overwintering pupae from late March to April emerged as adults and then laid eggs. The larvae of the 1st, 2nd, 3rd and 4th generations occurred from April to May, mid-June to mid-July, mid-August to mid-September and late October to November, respectively. Newly emerged adults like to move in a darker canopy, especially young branches and leaves. Each female adult can lay more than 10 to 100 eggs, mostly on the back of the leaves, and the eggs are scattered or aggregated.

2.2.1.6 the aphids harming red bayberry are mainly cotton aphids. Adults or nymphs suck juice on the new shoots, tender stems or buds of red bayberry, which affects the tree potential of red bayberry and induces soot disease. It occurs more than 8 generations a year in Zhejiang, overwintering with eggs on branches, hatching from mid-late February to mid-March, mostly from April to June and September to October, and overwintering by laying eggs in December.

2.2.2 Major diseases

2.2.2.1 Brown spot of red bayberry is commonly known as red spot of red bayberry, which mainly harms the leaves of red bayberry, causing a large number of fallen leaves, wilting flower buds, withering branchlets and weakening the tree until the tree dies. The pathogen overwintered with ascomycetes in fallen leaves or diseased leaves on trees, and the ascospores began to form from the end of April to the beginning of May the following year, and spread by wind and Rain Water. When the disease occurs, needle-sized fuchsia dots begin to appear on the leaf surface, and then gradually expand into a round or irregular shape, with a diameter of 4-8 mm. The center of the disease spot is reddish brown, the edge is brown or grayish brown, and in the later stage, the center of the disease spot becomes light brown or grayish white, and there are small black spots scattered on it. Most of the disease spots are connected to each other to form larger patches, causing the diseased leaves to dry and fall off. The severity of the disease is closely related to the number of Rain Water from May to June, the humidity of the bayberry orchard and the tree strength.

2.2.2.2 Cancer disease of red bayberry mainly harms the trunk or branches of red bayberry, especially the 2 ~ 3-year-old branches, which is the most serious disease on the branches of red bayberry. At the initial stage of the disease, milky white protuberances are produced on the diseased branches, the surface is smooth, and then gradually expand to form a tumor, the surface is uneven, rough, cork hard, brown or dark brown. The pathogen overwintered in the diseased branch tumor tissue, and in the following spring, the tumor surface overflowed bacterial pus, spread by wind and rain, and invaded from the host leaf scar or wound. The incubation period was 20-30 days, and the bacterial pus was continuously re-infected after the disease. From May to June, Rain Water was prone to disease, extensive management and poor drainage in the red bayberry garden.

2.2.2.3 Red clothing disease of red bayberry mainly harms the branches of red bayberry, especially the main branches and side branches, resulting in the weakness of the tree and the death of the branches until the death of the whole plant. The obvious feature of the disease is that the injured area is covered with a thin layer of pink mildew, the pathogen overwinters with mycelium in the diseased part, the temperature rises in the next spring, the leaves flow around, and powdery substances are produced at the edge of the old disease spot, which are spread by wind and rain. invade from the wound of red bayberry. The disease generally began to occur in late March and flourished from May to June. The peak period was from late May to early June and from early September to early October. The occurrence of the disease was closely related to temperature and rainfall. The disease was more serious in the warm and rainy season from April to June and alleviated in the high temperature and drought season from July to August.

2.2.2.4 White rot of red bayberry, also known as bayberry white rot and rotten bayberry, generally breeds white mildew on the fruit surface in the middle and later stages of bayberry mining. With the extension of time, the area of white spots gradually increases, generally less than 2 days. The white-spotted bayberry fruit falls to the ground, and the injured fruit can not be eaten. Bacteria overwintered in rotten fruit or soil, splashed the bacteria on the canopy near the ground by the impact of torrential rain, and then impacted by Rain Water, causing the whole crown to be infected. The more Rain Water in the mature period of red bayberry, the higher the maturity of red bayberry, the soft rot of fruit and the breeding of pathogens, the disease is usually more serious. In case of fruit fly damage, it often leads to bayberry white rot.

2.2.2.5 Waxberry wilt is a new disease of sudden branch and leaf wilting, which occurs to varying degrees in Ruian, Huangyan, Xianju, Linhai and Tiantai in Zhejiang Province. When the disease occurred, the leaves of bayberry branches and leaves were acute wilt at first, and then gradually showed withered yellow, brown yellow until withered to death. The leaves generally did not fall at the beginning of the symptom, and gradually fell after 1-2 months. One to two months after the disease, the aboveground parts of the young trees gradually withered, and the branches of the big trees died in the same year, which seriously affected the tree situation. The outbreak period of the disease is from March to September every year, and there are significant differences in susceptibility among varieties. Dongkui bayberry is the most common disease, while other varieties are lighter. Management measures have an impact on the disease of red bayberry, and trees with excessive fertilizer application and serious pruning are more likely to get sick.

2.2.2.6 shoot blight Waxberry shoot blight is a physiological disease caused by boron deficiency in bayberry trees. After the occurrence of the disease, bayberry shoots withered, branches clustered, leaves small, no fruit or a small amount of fruit. This disease often occurs in Lanxi and Linhai of Zhejiang Province. The occurrence of the disease is closely related to the planting environment and cultivation management measures of red bayberry, which is not only closely related to shallow soil layer, no application of organic fertilizer and excessive application of calcium superphosphate, but also related to the lack of available boron, exchangeable calcium and potassium and high content of available phosphorus in soil.

2.3 Green prevention and control techniques of bayberry diseases and insect pests

2.3.1 Prevention and control countermeasures the prevention and control of bayberry diseases and insect pests should proceed from the agricultural and forestry ecosystem as a whole, adhere to the plant protection policy of "prevention first, comprehensive control", give priority to agricultural, biological and physical control techniques, supplemented by necessary chemical control, stress the organic coordination and coordination of various control measures, sustainable control of diseases and insect pests, and achieve the goals of pest control, protection, safety, environmental protection and efficiency.

2.3.2 Green prevention and control technology

2.3.2.1 strengthen agricultural prevention and control (1) select disease-resistant varieties. The bayberry varieties suitable for large area cultivation in Zhejiang Province are Dongkui Waxberry, Water Chestnut species Waxberry, late Rice Waxberry and Ding Kui Waxberry. The grafted seedlings with developed root system, strong plant and no diseases and insect pests were selected for colonization. (2) reasonable close planting. The hillside land with fertile soil and good light conditions is selected to build the garden, and the red-yellow loam or yellow soil is the best. It can be planted in spring or autumn. Generally, 450 bayberry plants are planted per hectare with a row spacing of 4 × 5 m × 5 m. (3) applying fertilizer scientifically. Apply more organic fertilizer and supplement proper amount of trace elements such as calcium, magnesium, iron, boron, zinc, manganese, copper and molybdenum to promote the balanced and healthy growth of plants and improve disease resistance. (4) shaping and pruning. In the growing period (except the hanging fruit period) and dormant period, ring cutting, branch pulling and support, shoot picking, short cutting and thinning can be used to promote the strength of branches, increase the fruiting area and obtain high quality and high yield. (5) clear the garden in winter. When the temperature is low in winter, the pests go dormant and overwintering, and the spores and pathogens of the disease remain in the garden with the diseased leaves and branches cut off in winter. At this time, the pruned withered branches, fallen leaves and weeds can be centrally cleared out of the orchard for compost or deep burial. Scrape off the old warped skin and rough skin on the trunk, and brush the trunk and main branches of red bayberry with whitening agent to remove the overwintering places and pathogens of diseases and pests. Stone-sulfur mixture can also be used to spray tree trunks, branches and ground, or choose sodium oleate, mineral oil, engine oil and other agents to reduce the number of diseases and insect pests in the coming year.

2.3.2.2 popularize the physical control technology based on anti-insect net coverage

In view of the production practice of yield loss and quality decline caused by fruit flies during the harvest period of red bayberry, a single whole tree covering insect prevention net of red bayberry was carried out in Huangyan District, Taizhou City, Zhejiang Province (that is, 40 mesh insect control net was used as mantle before harvest. Mao bamboo or steel bar as a support for a single whole tree cover, referred to as Luoman Waxberry, figure 1) the experimental demonstration of the control effect on fruit flies. The results (Table 3) When the insect control net was hung 25 and 45 days before harvest, the insect fruit rate of red bayberry during fruit ripening was 8.75% and 6.25%, while that of the control area without insect control net was 87.50%. The average number of insects per fruit treated with anti-insect net was 0.08 and 0.05 respectively, while that in the control area was 6.19. The prevention and control effects of hanging anti-insect net treatment were 98.71% and 99.19% respectively. This method can block the harm of fruit flies and other pests to bayberry, stop or reduce the use of chemical pesticides, and ensure the edible safety of bayberry fruit. Red bayberry is a crop that likes shade and moisture tolerance. After hanging the net, it has the effect of shading and moisturizing in sunny days, and it can protect against rain and heat on rainy days, which is beneficial to the development of red bayberry fruit. It can appropriately postpone the ripening period of red bayberry for 2-3 days, and improve the appearance quality and yield of red bayberry fruit. The market price of red bayberry is generally increased by more than 30%, and the average income per plant of red bayberry is increased by 40% and 50%. In addition, the use of light, sexual inducement, color plate and sugar and vinegar solution also has a certain control effect on pests such as Lepidoptera, Homoptera, Coleoptera and Diptera.

Fig. 1 cultivation technique of mantle mulching

Fig.1 Netcovering cultivation technique

Table 3 Control effect of insect control net cover on red bayberry fruit fly

Table 3 Controleffects ofinsectnetcultivation technique on M.rubra fruitflies

After the same column of data, different lowercase letters showed significant differences (P < 0.05). Table 4 and Table 5 are the same.

Differentlowercase letters in the same column represented significantdifference. The same was applied in Table 4 and Table 5

2.3.2.3 Chemical control of bayberry diseases and insect pests has many kinds and serious harm, so drug control is inevitable. Pesticides with high efficiency, low toxicity and low residue should be selected, which are safe to people and animals and have no pollution to the environment. Botanical and biological pesticides should be preferred. The results of experiments on the control effects of different agents on red bayberry flies (Table 4 and Table 5) showed that the control effects of spraying 60 g L ethyl spinosad suspension 2000 times on bayberry flies 20, 30 and 45 days before harvest were 96.17%, 95.63% and 93.72%, respectively. The control effects of spraying 20% sodium oleate soluble powder 200,300,400 times and 25% thiazinone wettable powder 1000 times on bayberry scale insects 15 days before harvest were 97.24%, 85.99%, 35.13% and 76.48%, respectively. The results showed that biological pesticides ethyl spinosad and sodium oleate had good control effects on bayberry fruit fly and shell insects. Ethyl spinosad is suitable for spray control with 2000 times liquid and 20% sodium oleate, and it is safe to use. at present, these two agents have been registered in bayberry and can be popularized and applied in production.

Table 4 the control effect of 60 g / L ethyl spinosad suspension 2000 times on Drosophila melanogaster

Table 4 Controleffects of 60 g/L spinetoram SC 2000 times liquid on M.rubra fruitflies

Table 5 Control effect of 20% sodium turpentine soluble powder and 25% thiazinone wettable powder on bayberry scale insect

Table 5 Controleffects of 20%sodium pimaric acid SP and 25%buprofezin WP on M.rubra scale insects

2.3.2.4 Protection and utilization of natural enemies biological control is a method of using beneficial or other organisms to suppress or eliminate pests, including the use of natural enemies insects, microorganisms and biological agents to achieve biological control effects such as insect control with insects, mites with mites, insects with bacteria, bacteria with bacteria, etc. According to the investigation, there are many kinds of natural enemies of bayberry pests in Zhejiang Province. the predatory natural enemies are Chrysopa Sinica (Chrysopa sinica Tjeder), Chrysopa (Chrysopa Formosa Brauer), Chrysopa (Chrtsopa septempunctata Wesmael) [Jishan Huayao], Harmoia axyridis Pallas and Chilocorus rubidus Hope, while the parasitic natural enemies are Encyrtidae, Aphelinidae, Tetrastichinae and Pteromalidae. Eulophidae and Cleonymidae Hymenoptera parasitized the leaf roll moth, and Brachymeria lasus Walker parasitized Sapium sebiferum. Among them, aphid wasp, jumping wasp and broad-legged wasp were the important natural enemies of bayberry pests. It is necessary to protect the natural ecological environment of mountain forests, maintain ecological balance, give full play to the role of natural enemies, and continuously control the occurrence of bayberry pests.

3 discussion

Red bayberry is a traditional fruit in Zhejiang Province, which is planted in most counties (cities). It ranks first in the output value of fruit trees in Zhejiang, and it is a pillar industry for farmers in Taizhou, Wenzhou, Ningbo and Lishui and other mountainous areas to get rich. Through the systematic general survey and fixed-point monitoring of the main producing areas of Waxberry in Zhejiang Province, and synthesizing the studies of Chen Zongliang (1995), Wang Hongxiang (1999), Gong Jieqiang and Wang Hongxiang (2002), Lai Yanxue (2003), Liu Yougao (2006), Qi Xingjiang (2014), etc., it is preliminarily found that there are 69 species of insect pests and 22 species of diseases on Waxberry in Zhejiang Province. Among them, 12 kinds of diseases and pests, such as shell insect, fruit fly, leaf roll moth, inchworm, whitefly, aphid and brown spot, cancer, red clothes disease, white rot, wilt and tip blight are the main diseases and insect pests of bayberry, and they are also the main objects of prevention and control. There are many varieties of bayberry in Zhejiang, mainly Dongkui bayberry in Taizhou and Lishui, water chestnut species Waxberry in Wenzhou, Yangmei in Cixi, Ningbo and late rice bayberry in Zhoushan. Due to different natural ecological conditions, cultivation management models and cultivated varieties, there are significant differences in the occurrence and damage degree of bayberry diseases and insect pests. In this study, only a preliminary survey of red bayberry diseases and insect pests in Zhejiang Province was conducted, and the occurrence dynamics of major diseases and insect pests in different bayberry planting regions, different elevations, different orchards and red bayberry years need to be further investigated and analyzed.

Red bayberry is a naked fruit without exocarp, and its safety has always attracted much attention. This study puts forward the green prevention and control technology of the prevention and control of bayberry diseases and insect pests and the coordination and organic cooperation of agricultural, biological, physical and chemical control, which has important guiding significance for scientifically guiding the prevention and control of bayberry diseases and insect pests and ensuring safety in production. In practice, the project unit explored and summarized a set of anti-insect net covering cultivation technology of red bayberry, which can effectively block the harm of pests such as fruit flies, improve fruit quality, increase the price of fresh fruit, and increase economic benefits. it is a cultivation and management mode with simple operation and high ecological efficiency, and it is also an innovative technology to promote the quality and safety of bayberry fruit. In addition, insect traps and fruit fly sex attractants also have certain control effects on pests such as Lepidoptera, Homoptera, Coleoptera and Diptera, which can be used with insect control nets to improve the overall control effect on bayberry pests.

According to the production situation of red bayberry in Zhejiang, there are many kinds of diseases and insect pests, and the diseases and insect pests are widely controlled (Chen Zongliang, 1995; Gong Jieqiang and Wang Hongxiang, 2002; Lai Yanxue, 2003; Liu Yougao, 2006; Liang Senmiao et al., 2008). The results showed that the control effect of 60 g L ethyl spinosad suspension 20, 30 and 45 days before harvest and 20% sodium turpentine soluble powder 15 days before harvest were more than 90.00%. And these two agents have been registered on bayberry and can be widely used in production. At present, the pesticides registered and used in Waxberry include buprofezin, quinoline copper, avermectin, mineral oil and engine oil, which can be used to control bayberry whitefly, aphids, scale insects and brown spot. However, there is still a lack of registered pesticides for diseases and insect pests such as bayberry leaf roll moth, inchworm, cancer, red clothes disease and white rot. The main reason is that Waxberry is a characteristic small crop in China, and the safety requirements for drug use are high. The cost of registration is not proportional to the benefit, and the pesticide enterprises lack the enthusiasm of registration. therefore, it is suggested that the relevant departments should strengthen the support for pesticide registration of characteristic crops such as red bayberry, speed up the screening of safe and efficient pesticides, do a good job in field experiments on efficacy and residues, speed up the process of pesticide registration and the formulation of standards for pesticide residue control, so that they can be used medicinally, well and scientifically, and put drugs into practice according to law and scientifically. Ensure the quality and safety of bayberry.

4 conclusion

The results showed that there were 69 species of common bayberry pests in Zhejiang Province, belonging to 5 orders and 29 families, and 22 common diseases, including 15 fungal diseases, 1 bacterial disease, 5 physiological diseases and 1 root knot nematode. Twelve kinds of diseases and insect pests, such as bayberry scale insect, fruit fly, leaf roll moth, inchworm, whitefly, aphid and brown spot, cancer, red clothes disease, white rot, wilt and tip blight were taken as the main diseases and insect pests of bayberry. Find out the main epidemic rules and influencing factors, and identify the main prevention and control objects. In production, according to the types and occurrence characteristics of diseases and insect pests, comprehensive control measures with the combination of agricultural, biological, physical and chemical control should be adopted to effectively control the occurrence of bayberry diseases and insect pests.