Repellent for controlling eurygaster integriceps

Abstract

The application relates to a repellent for preventing and treating tea pseudocotyledon leafhoppers, which is composed of the following raw materials in proportion by weight: Enteromorpha prolifera fermentation liquor 50-70%, gardenia flower extract 15-25%, guava leaf extract 15-25% and an auxiliary agent 0.05-0.5%. The repellent for preventing and treating tea pseudocotyledon leafhoppers has a strong repelling effect on the tea pseudocotyledon leafhoppers, and also has the functions of leaf fertilizer and the like, can protect the tea leaves from tender shoots and new bud leaves, and the like, is convenient to use, and has an excellent application prospect.

Description

Technical Field

[0001] This invention relates to pest control technology in tea gardens, and in particular to a repellent for controlling the tea false-eyed leafhopper. Background Technology

[0002] my country ranks first, second, and third in the world in terms of tea garden area, output, and export volume, respectively. Currently, my country has about 10,000 hectares of organic tea gardens. These tea gardens are not allowed to use chemical fertilizers and pesticides, but pests still occur seriously, especially the false-eyed green leafhopper, for which there are no effective control measures.

[0003] The tea false-eyed green leafhopper, belonging to the order Hemiptera and family Cicadidae, is a common and major pest in my country's tea-growing regions, and is also the number one pest of tea trees in my country. It primarily infests tea buds and leaves by piercing and sucking their sap, causing bud and leaf withering, reddening of leaf veins, reddish-brown scorching of leaf tips and margins, and stunted growth of new shoots, thus affecting tea yield and quality. In the middle and lower reaches of the Yangtze River in my country's tea-growing areas, this insect can cause losses of over 10% in summer and autumn tea in normal years, and as high as 50% in years with severe infestations.

[0004] Because this insect is small and its damage is very insidious, and it has as many as 9 generations per year, with a fast reproduction rate and serious generation overlap, it is difficult to control. Therefore, doing a good job in controlling the false-eyed green leafhopper is an important guarantee for tea production.

[0005] Currently, the control of the tea false-eyed green leafhopper mainly focuses on forecasting, physical methods, chemical agents, and biological control. Chemical control, especially driven by short-term profits and due to tea farmers' weak environmental awareness, has led to serious misuse, overuse, and abuse of pesticides, resulting in rampant damage and the emergence of pesticide resistance in the leafhopper. It also causes large-scale losses of natural enemies and significant pesticide residues in tea leaves. Furthermore, the tea leafhopper's strong attraction to tender leaves, aversion to light and moisture, tendency to inhabit the undersides of leaves, and its ability to move horizontally, jump easily, and multi-host characteristics make general chemical control ineffective and prone to causing pesticide residues in tea. While biological control of the false-eyed green leafhopper offers high environmental safety, current technologies are not mature enough, resulting in poor control effects. Many technologies are still in the research and demonstration stage, with limited application.

[0006] Given the increasing awareness of food safety and the national policy of reducing pesticide use and emissions, finding effective and safe methods for controlling the tea green leafhopper is an important issue for tea production.

[0007] Insect repellents are active chemical substances produced by plants or synthesized artificially that repel insects. Repellents do not kill the insects themselves; they repel them through the release of volatile odors. Repellents are widely used against mosquitoes, sanitary pests, and grain pests. Currently, there are no reports on the research and application of repellents similar to foliar fertilizer spraying in the tea leafhopper. Because repellents have high environmental safety, a broad target spectrum, and strong repellency efficacy, they are also an important technology and method for the ecological control of agricultural pests.

[0008] Therefore, developing repellents for the tea false-eyed green leafhopper has great practical value. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of existing tea leafhopper control technologies and provide a repellent for controlling tea leafhoppers. This repellent combines plant fermentation and extraction technologies, which can not only effectively control tea leafhoppers but also provide nutrients for tea growth. It can be used as a foliar fertilizer for regular spraying and can be used for a long time without any toxic effects.

[0010] Ulva prolifera is a type of green tide algae widely distributed in the coastal waters of coastal countries. It can be used as a food ingredient, animal feed, organic fertilizer, plant growth regulator, and is commonly used medicinally to treat skin diseases. Currently, Ulva prolifera grows extensively in coastal areas, accumulating along the coast. It is a harmful green tide algae, and its common use is to make seaweed strips and seaweed cakes. However, due to its high salt content, unfermented Ulva prolifera bio-fertilizer is difficult for the soil to decompose and absorb, therefore it cannot be used directly as organic fertilizer, and its fertilizer value is difficult to achieve effective utilization.

[0011] This invention employs microbial fermentation technology. After fermentation under specific conditions, the utilization rate of *Ulva prolifera* can be increased. More importantly, it solves the problem of *Ulva prolifera* requiring primers such as ethanol or desalination. Using this microbial fermentation technology, the fermentation of *Ulva prolifera* can be completed within two months, decomposing the indigestible cellulose and other polysaccharides in the *Ulva prolifera*, making the nutrients in the *Ulva prolifera* easier for crops to absorb and utilize, thus improving the nutritional value of the bio-organic fertilizer. It also promotes the release of bioactive substances such as plant growth hormones, gibberellins, and microsporidians from the *Ulva prolifera*, facilitating soil absorption and conversion to meet the needs of crop growth. Furthermore, the seaweed polysaccharides and mannitol in seaweed biotin have redox activity on crops such as tea, promoting the transport of various nutrients to tea leaves, improving the taste of the tea, increasing its sugar content and other high-grade characteristics, and extending the tenderness retention period of the tea leaves, i.e., the harvesting period.

[0012] In this invention, osmanthus flowers and guava leaves have good repellent effects on some insects. When mixed with the fermented liquid of seaweed in a certain proportion, they exert a synergistic effect and can greatly improve the use effect.

[0013] To address the problem that foliar bio-fertilizers do not adhere well to tea leaves and are washed away by rainwater during or after application, this invention also incorporates chitosan and other additives, thereby enabling the insect-repellent foliar bio-fertilizer of this invention to maintain its insect-repellent effect for 7-10 days.

[0014] The specific plan is as follows: A repellent for controlling the tea leafhopper (Tea false-eyed leafhopper) comprises the following raw materials in the indicated weight proportions: 50-70% *Ulva prolifera* fermentation liquid, 15-25% *Osmanthus fragrans* flower extract, 15-25% *Guava* leaf extract, and 0.05-0.5% adjuvants. The *Ulva prolifera* fermentation liquid is prepared by washing and drying *Ulva prolifera*, pulverizing it into granules, then adding water, biodegrading enzymes, and microbial flora for fermentation. After fermentation, the liquid is sieved to obtain the *Ulva prolifera* fermentation liquid. The biodegrading enzymes are a mixture of alginate lyase, carrageenanase, and agarase, and the microbial flora is a complex bacterial enzyme solution containing agricultural plant enzymes and *Bacillus subtilis*.

[0015] Furthermore, in the preparation method of the *Ulva prolifera* fermentation liquid, the *Ulva prolifera* is crushed into particles with a size of 50-80 mesh, and the amount of water used is 10-20 times the weight of the *Ulva prolifera* particles.

[0016] Furthermore, the mass ratio of alginate lyase, carrageenanase, and agarase in the biodegrading enzyme is (1-2):(1-2):(1-2), wherein the concentrations of alginate lyase, carrageenanase, and agarase in the fermentation broth are each independently 0.05-0.5 g / L, preferably 0.1-0.2 g / L.

[0017] Furthermore, the concentrations of the agricultural plant enzyme and the Bacillus subtilis in the fermentation broth are each independently 0.05-0.5 g / L, preferably 0.1-0.2 g / L.

[0018] Furthermore, the fermentation conditions include fermentation at 20-50℃ for 30-60 days, using aerobic fermentation, and after fermentation, filtering with a 100-200 mesh filter to obtain the Ulva lactuca fermentation liquid.

[0019] Furthermore, the osmanthus flower extract is an aqueous extract of osmanthus flower branches and leaves. Preferably, the osmanthus flower extract is prepared by cutting osmanthus flowers into 2-5 cm long sections, adding pure water, boiling for 20-40 minutes, and then filtering. Preferably, the guava leaf extract is an aqueous extract or an alcoholic extract. More preferably, the guava leaf extract is prepared by adding guava leaves to a mixture of pure water or ethanol and water, boiling for 20-40 minutes, and then filtering.

[0020] Furthermore, the mass ratio of the *Ulva prolifera* fermentation liquid to (the *Osmanthus fragrans* extract + *Guava* leaf extract) is (1-3):1, preferably 2:1.

[0021] Furthermore, the additive is a thickener, preferably chitosan, and is used in an amount of 0.1-0.3% of the total weight.

[0022] Furthermore, the repellent for controlling the tea false-eyed leafhopper has an average repellency rate of 95-100% against the tea false-eyed leafhopper.

[0023] This invention also protects a method for preparing the repellent for controlling the tea false-eyed leafhopper, comprising the following steps: (1) After washing and drying the seaweed, crush it into particles, then add water, biodegradable enzymes and microbial flora for fermentation. After fermentation, sieve the liquid to obtain the seaweed fermentation liquid. (2) Boil pure water in a mixture of osmanthus flowers and guava leaves, filter and let stand to obtain a plant combination extract; or prepare the osmanthus flower extract and the guava leaf extract separately, and then mix the two to obtain a plant combination extract. (3) Mix the fermented broth of Ulva prolifera with the plant combination extract and the adjuvant, and stir until homogeneous.

[0024] Beneficial effects: The repellent for tea false-eyed leafhopper in this invention has a strong repellent effect on tea false-eyed leafhopper, and can also supplement the growth nutrients of tea gardens. It can be used as a foliar fertilizer and has excellent application prospects.

[0025] Furthermore, this invention involves fermenting Ulva prolifera under the action of microbial flora, which not only improves the utilization rate of Ulva prolifera and increases economic benefits, but also produces a product with functions such as foliar fertilizer. Combined with ingredients such as Osmanthus fragrans and Guava leaves, it exerts a synergistic effect in repelling the tea leafhopper. Moreover, this product also has the advantages of protecting tea leaves from sprouting tender shoots and new buds. Detailed Implementation

[0026] Preferred embodiments of the present invention will now be described in more detail. While preferred embodiments of the present invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products. In the following embodiments, unless otherwise explicitly stated, "%" refers to weight percentage.

[0027] The following testing methods are included: Methods for measuring control efficacy: Randomly selected tea gardens were used in a control experiment. The treatment group received a repellent, diluted 50 times with the repellent stock solution, sprayed weekly during the tea production period. The control group received no repellent treatment. The number of leafhoppers in the tea gardens was recorded regularly, and the repellent rate was calculated using the following formula:

[0028] In the formula, R represents the repellency rate; C represents the number of leafhoppers captured in the control group (on the tea tree canopy without repellent); and T represents the number of leafhoppers captured in the treatment group (on the tea tree canopy with repellent).

[0029] Damage rate refers to the percentage of leaves damaged by leafhoppers out of every 100 young leaves, and the formula is: Damage rate = (Number of leaves with leafhopper piercing holes / Total number of leaves surveyed) × 100% The repellency rate is the reduction rate of the number of leafhoppers captured per unit area of ​​tea tree canopy in tea gardens. The higher the repellency rate, the fewer leaves on the tea plantations that are pierced and sucked by leafhoppers. Therefore, the relationship between the damage rate and the repellency rate is inverse.

[0030] Example 1 The preparation of a repellent for controlling the tea false-eyed leafhopper includes the following steps: (1) After washing and air-drying the seaweed, crush it into particles with a size of 50-80 mesh, and then add it to a warm water solution with a weight of 15 times, along with an appropriate amount of biodegradable enzymes and microbial flora.

[0031] Specifically, the biodegrading enzymes are: alginate lyase 0.1 g / L, carrageenase 0.1 g / L, and agarase 0.1 g / L, in a weight ratio of 1:1:1. The microbial community is a complex bacterial enzyme solution containing agricultural plant enzymes 0.2 g / L, Bacillus subtilis 0.1 g / L, with the remainder being water.

[0032] Fermentation is carried out at room temperature (20-50℃) for 30-60 days to obtain the Ulva fermentation broth. The Ulva fermentation broth A is obtained by filtering it through a 100-200 mesh filter.

[0033] (2) Osmanthus fragrans flowers (cut into 2-5 cm long sections) and guava leaves were mixed in a 1:1 weight ratio, and then boiled in pure water for 30 minutes. After filtration and settling, the aqueous extract of plant combination B was obtained.

[0034] (3) Mix the fermentation liquid A of Ulva prolifera and the water extract of plant combination extract B at a mass ratio of 1.5:1, then add chitosan, with chitosan accounting for 0.1 wt% of the total weight of the mixture, to obtain the repellent for foliar fertilizer spraying.

[0035] Example 2 Referring to Example 1, the only difference is that the mass ratio of the *Ulva prolifera* fermentation liquid A to the water extract of plant combination B (osmanthus flower + guava leaf) is 2:1.

[0036] Example 3 Referring to Example 1, the only difference is that the mass ratio of the *Ulva prolifera* fermentation liquid A to the water extract of plant combination B (osmanthus flower + guava leaf) is 3:1.

[0037] Example 4 Referring to Example 1, the only difference is that the mass ratio of the *Ulva prolifera* fermentation liquid A to the water extract of plant combination B (osmanthus flower + guava leaf) is 1:1.

[0038] Example 5 Referring to Example 1, the only difference is that the concentrations of alginate lyase, carrageenanase, and agarase used in the fermentation of Ulva prolifera are 0.2 g / L, 0.4 g / L, and 0.3 g / L, respectively.

[0039] Example 6 Referring to Example 1, the only difference is that the concentrations of agricultural plant enzymes and Bacillus subtilis during the fermentation of Ulva prolifera were 0.1 g / L and 0.2 g / L, respectively.

[0040] Example 7 Referring to Example 1, the only difference is that the additive used is alginate, and the amount is 0.2 wt%.

[0041] Experiment 1 for Calculating the Effectiveness of the Disease The experiment was conducted in a tea garden in Xiandu Town, Hua'an County. The results are shown in Tables 1 and 2. It can be seen that in the experimental tea fields of Xiandu Town, Hua'an County, the number of tea leafhoppers (*Tea False Eye Green Leafhopper*) showed an increasing trend in the control area (where no repellent was sprayed). In the sprayed areas, the repellency rate of Group 1 (Example 1) was 95.8% on July 13, 2019 (7 days after spraying), while the repellency rate reached 100% on July 23 and July 31 (lasting for 8 days). The reason for this needs further verification through experimentation. Groups 2, 3, and 4 (with added plant extracts) all achieved a 100% repellency rate after spraying. Table 1 also shows that the longest duration of efficacy for Groups 1 to 4 was from July 6 to July 31, 2019, a duration of up to 24 days.

[0042] Moreover, after using the repellent prepared in the example, the tea plants in the tea garden grew well, and the average yield of tender shoots and leaves per mu increased by more than 8%.

[0043] Table 1. Repellency rate (%) of the repellent against leafhoppers in a tea garden in Xiandu Town, Hua'an County (spraying started on July 6).

[0044] Table 2. Damage rates on tea leaves in different treatment areas and comparison areas in tea gardens of Xiandu Town, Hua'an County.

[0045] Experiment 2 for Calculating the Effectiveness of the Defense The experiment was conducted at Qingyuan Mountain Tea Garden in Quanzhou. The results are shown in Tables 3 and 4. It can be seen that in the Qingyuan Mountain Tea Garden experiment, from July 18th to August 1st, 2019, the infestation rate of tea leafhoppers increased from 58% in the control group to over 90%. However, the average infestation rate of leafhoppers on the leaves in Example 1, Example 2, Example 3, and Example 4 groups was lower. Example 2 group showed the best protective effect. In the experiment, the number of false-eyed green leafhoppers captured on the tea leaves in the control area was also higher. Although a small number of tea false-eyed green leafhoppers were captured in the experimental groups, the control effect was significantly better than that in the control group.

[0046] Table 3. Repellency rate (%) of the repellent against leafhoppers in Qingyuan Mountain Tea Garden, Quanzhou (spraying started on July 18).

[0047] Table 4. Damage rates on tea leaves in different treatment areas and comparison areas in Qingyuan Mountain Tea Garden, Quanzhou.

[0048] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0049] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0050] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A repellent for controlling the tea false-eyed leafhopper, characterized in that: The product is composed of the following raw materials: *Ulva prolifera* fermentation broth, plant extract, and adjuvants. The preparation method of the *Ulva prolifera* fermentation broth is as follows: *Ulva prolifera* is washed, dried, and pulverized into granules. Water, biodegrading enzymes, and microbial flora are then added for fermentation. After fermentation, the liquid is sieved to obtain the *Ulva prolifera* fermentation broth. The biodegrading enzyme is a mixture of alginate lyase, carrageenanase, and agarase, with a mass ratio of (1-2):(1-2):(1-2). The concentrations of alginate lyase, carrageenanase, and agarase in the fermentation broth are each independently 0.05-0.5 g / L. The microbial flora is a compound bacterial enzyme solution containing agricultural plant enzymes and *Bacillus subtilis*, with the concentrations of agricultural plant enzymes and *Bacillus subtilis* in the fermentation broth each independently 0.05-0.5 g / L. The fermentation conditions include fermentation at 20-50℃ for 30-60 days using aerobic fermentation. The method for preparing the plant combination extract is as follows: Osmanthus fragrans branches and leaves and guava leaves are mixed in a weight ratio of 1:1, added to pure water and boiled. After filtration and standing, the plant combination extract is obtained. The mass ratio of the *Ulva prolifera* fermentation liquid to the plant combination extract is (1-3):

1. The *Ulva prolifera* fermentation liquid accounts for 50-70% of the total weight of the repellent, and the adjuvant accounts for 0.05-0.5% of the total weight of the repellent.

2. The repellent for controlling the tea false-eyed leafhopper according to claim 1, characterized in that: In the preparation method of the *Ulva prolifera* fermentation liquid, the *Ulva prolifera* is crushed into particles with a size of 50-80 mesh, and the amount of water used is 10-20 times the weight of the *Ulva prolifera* particles.

3. The repellent for controlling the tea false-eyed leafhopper according to claim 2, characterized in that: Of the biodegrading enzymes, the concentrations of the alginate lyase, the carrageenanase, and the agarase in the fermentation broth are each independently 0.1-0.2 g / L.

4. The repellent for controlling the tea false-eyed leafhopper according to claim 2, characterized in that: The concentrations of the agricultural plant enzyme and the Bacillus subtilis in the fermentation broth are each independently 0.1-0.2 g / L.

5. The repellent for controlling the tea false-eyed leafhopper according to any one of claims 1-4, characterized in that: The fermentation conditions include filtering the fermented liquid of *Ulva prolifera* through a 100-200 mesh filter after fermentation.

6. The repellent for controlling the tea false-eyed leafhopper according to claim 1, characterized in that: The mass ratio of the *Ulva prolifera* fermentation broth to the plant combination extract is 2:

1.

7. The repellent for controlling the tea false-eyed leafhopper according to any one of claims 1-4, characterized in that: The additive is a thickener.

8. The repellent for controlling the tea false-eyed leafhopper according to claim 7, characterized in that: The additive is chitosan, and its dosage is 0.1-0.3% of the total weight.

9. A method for preparing the repellent for controlling the tea false-eyed leafhopper according to any one of claims 1-8, characterized in that: Includes the following steps: (1) After washing and drying the seaweed, crush it into particles, then add water, biodegradable enzymes and microbial flora for fermentation. After fermentation, sieve the liquid to obtain the seaweed fermentation liquid. (2) Add pure water to a mixture of osmanthus flowers and guava leaves, boil, filter and let stand to obtain a plant combination extract; (3) Mix the fermented broth of Ulva prolifera with the plant combination extract and the adjuvant, and stir until homogeneous.

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