Multi-element composite-based bee mite control agent and preparation method thereof

Abstract

The invention discloses a multi-element compounding-based bee mite control agent and a preparation method thereof, and relates to the field of agricultural biological control, the multi-element compounding-based bee mite control agent comprises compound fermentation metabolites and natural elements in a fermentation culture medium, the compound fermentation metabolites comprise bacillus amyloliquefaciens, trichoderma, saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, beauveria bassiana and metarhizium anisopliae, the inoculation weight components are bacillus amyloliquefaciens, trichoderma, saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, beauveria bassiana and metarhizium anisopliae. The bee mite prevention and control agent is prepared through a biological fermentation technology in a setting mode that various beneficial microorganisms and natural elements serve as main raw materials, so that the bee mite prevention and control agent does not contain harmful chemical substances, chemical residues cannot be generated in bee products in the using process, the production standard of organic bee products is completely met, and the production cost is reduced. Meanwhile, adverse effects on growth, development and reproduction of bees and normal activities of bee colonies are avoided, and the health of the bee colonies is effectively guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural biological control, in particular to a bee mite control agent based on multi-element complex and a preparation method thereof. BACKGROUND

[0002] In the honeybee breeding industry, there are usually parasites, including bee mites, which not only directly attach to the body surface of honeybees to suck their body fluids, causing the body weakness and shortening the life span of honeybees, but also spread various viruses in the bee colony, causing large-scale outbreaks of honeybee diseases, and further causing the sharp reduction of the number of bee colonies, which seriously affects the yield and quality of honey, royal jelly and other bee products, and thus usually requires bee mite control operation.

[0003] In the prior art, chemical acaricides are usually used for controlling bee mites. However, if chemical acaricides are used for a long time, on the one hand, bee mites are prone to developing drug resistance to chemical acaricides, and chemical acaricides may be left in bee products, which gradually reduces the acaricidal effect, and thus it is necessary to increase the dosage or replace the type of acaricides, forming a vicious cycle. On the other hand, not only does it reduce the quality of bee products, but also poses a potential threat to human health, which does not meet the demand of modern consumers for green and safe food. At the same time, some chemical acaricides also have certain toxicity to bees, which may cause additional harm to the bee colony while killing bee mites, further weakening the vitality of the bee colony. Therefore, it is necessary to use a bee mite control agent based on multi-element microbial complex fermentation to replace the control method of chemical acaricides. SUMMARY

[0004] The present application aims to provide a bee mite control agent based on multi-element complex and a preparation method thereof to solve the problems raised in the background.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a bee mite control agent based on multi-element complex, comprising a complex fermentation metabolite and natural elements in a fermentation medium, wherein the complex fermentation metabolite comprises Bacillus amyloliquefaciens, Trichoderma, Saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, Beauveria bassiana and Metarhizium, and the inoculation weight components are as follows:

[0006] Bacillus amyloliquefaciens 4-6 g / L

[0007] Trichoderma 4-6 g / L

[0008] Saccharomyces cerevisiae 18-21 g / L

[0009] Photosynthetic bacteria 18-21 g / L

[0010] Lactic acid bacteria 18-21 g / L

[0011] Beauveria bassiana 1-3 g / L

[0012] Metarhizium 1-3 g / L;

[0013] The Bacillus amyloliquefaciens, Trichoderma, Saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, Beauveria and Metarhizium are used for synergistically inhibiting chitin synthesis of mites and decomposing proteins in mites;

[0014] The natural elements in the fermentation medium include an inducing agent, selenium-rich yeast, nano zinc oxide, tea saponin and sugarcane molasses, which are used for enhancing immunity of bees and destroying body wall of mites.

[0015] Preferably, the inducing agent includes chitosan oligosaccharide and taurine, and the content of the chitosan oligosaccharide and taurine in the medium is as follows:

[0016] Chitosan oligosaccharide 4-6 g / L

[0017] Taurine 19-21 g / L.

[0018] Preferably, the content of the selenium-rich yeast and nano zinc oxide in the fermentation medium is respectively:

[0019] Selenium-rich yeast 3-8 g / L

[0020] Nano zinc oxide 1-3 g / L.

[0021] Preferably, the content of the tea saponin and sugarcane molasses in the fermentation medium is respectively:

[0022] Tea saponin 19-21 g / L

[0023] Sugarcane molasses 98-101 g / L.

[0024] Preferably, the content of the antibacterial peptide in the compound fermentation metabolite is not less than 1.2 mg / mL, the content of the organic acid is not less than 5.0 mg / mL, the photosynthetic bacteria are Rhodopseudomonas palustris, and the lactic acid bacteria are Lactobacillus plantarum.

[0025] A preparation method of a bee mite control agent based on multi-element compound, characterized in that it comprises the following specific steps:

[0026] Step one: 100 g / L of sugarcane molasses, 20 g / L of tea saponin, 20 g / L of taurine, 5 g / L of chitosan oligosaccharide, 3-8 g / L of selenium-rich yeast and 1-3 g / L of nano zinc oxide are mixed and dissolved, stirred uniformly, and then the pH value is adjusted to prepare a fermentation medium;

[0027] Step two: Bacillus amyloliquefaciens 5g / L, Trichoderma 5g / L, Saccharomyces cerevisiae 20g / L, photosynthetic bacteria 20g / L, lactic acid bacteria 20g / L, Beauveria bassiana 2g / L and Metarrhizium anisopliae 2g / L are respectively activated and cultured, and then inoculated into the fermentation medium in step one according to the weight component of inoculation;

[0028] Step three: the components in the fermentation medium are subjected to aerobic fermentation, and after the aerobic fermentation is completed, static anaerobic fermentation is carried out;

[0029] Step four: after the oxygen fermentation is completed, the fermentation broth is subjected to centrifugal treatment, then the supernatant is collected, and then the supernatant is subjected to sterilization filtration by using a filter membrane to obtain a compound fermentation liquor, i.e., a mite control agent stock solution, and then a mite control effect test is carried out.

[0030] Preferably, the temperature, stirring speed and aeration amount of the aerobic fermentation in step three are 30 DEG C, 200rpm and 1.0-1.5vvm respectively, and the fermentation time of the aerobic fermentation is 24h.

[0031] Preferably, the fermentation temperature of the oxygen fermentation in step three is 25 DEG C, and the fermentation time of the oxygen fermentation is 48h.

[0032] Preferably, the centrifugal speed of the centrifugal treatment in step four is 8000-10000rpm, and the centrifugal time of the centrifugal treatment is 15-20min.

[0033] Preferably, the pore size of the filter membrane in step four is 0.22mu m.

[0034] Technical effects and advantages of the present application:

[0035] (1) The present application is prepared by using a plurality of beneficial microorganisms and natural elements as main raw materials through a biological fermentation process, so that the mite control agent does not contain harmful chemical substances, does not produce chemical residues in the bee products during use, completely meets the production standards of organic bee products, does not cause adverse effects on the growth and development, reproduction and normal activities of the bee colony, effectively guarantees the health of the bee colony, and provides a strong guarantee for producing green, safe and high-quality bee products.

[0036] (2) The present application can synergistically inhibit chitin synthesis of mites and decompose proteins in the body of mites through the setting mode of metabolic products produced by various microorganisms such as Bacillus amyloliquefaciens, Trichoderma, Beauveria and Metarrhizium during fermentation, kill mites from multiple target points, and at the same time, the addition of natural elements such as selenium-rich yeast, nano zinc oxide, chitosan and tea saponin can not only enhance the immunity of bees, but also destroy the body wall of mites, further improve the acaricidal effect, the double action mechanism of microbial metabolites and complex natural elements effectively reduces the possibility of mite drug resistance, and ensures the effectiveness of long-term use of the control agent;

[0037] (3) The present application can regulate intestinal microflora balance, promote the digestion and absorption of nutrients by bees, enhance the immunity and disease resistance of bees, reduce the occurrence of bee diseases, and effectively improve the yield and quality of bee products such as honey and royal jelly, so as to bring higher economic benefits to bee farmers.

[0038] (4) The present application uses agricultural by-products such as sugarcane molasses as the main fermentation raw material during fermentation, which is beneficial to greatly reducing the production cost of the control agent, and at the same time, the segmented fermentation process and post-treatment steps can be realized by using conventional equipment, which is simple to operate and easy to scale up and industrialize, thereby being beneficial to the broad market prospect of the bee mite control agent at low cost and simple production process, so that more bee farmers can obtain high-efficiency bee mite control effect with low investment. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The present application is based on the preparation method of the bee mite control agent with multiple element complex. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0041] The present application provides a bee mite control agent with multiple element complex, which comprises the following components in parts by weight: Figure 1The multi-element composite-based tracheal mite control agent shown includes a composite fermentation metabolite and natural elements in a fermentation medium, the composite fermentation metabolite includes Bacillus amyloliquefaciens (CGMCC 1.3358), Trichoderma (ATCC 20846), Saccharomyces cerevisiae (CICC 31012), photosynthetic bacteria, lactic acid bacteria, Beauveria bassiana, and Metarhizium anisopliae, and the inoculation weight components are as follows:

[0042] Bacillus amyloliquefaciens 4-6 g / L

[0043] Trichoderma 4-6 g / L

[0044] Saccharomyces cerevisiae 18-21 g / L

[0045] Photosynthetic bacteria 18-21 g / L

[0046] Lactic acid bacteria 18-21 g / L

[0047] Beauveria bassiana 1-3 g / L

[0048] Metarhizium anisopliae 1-3 g / L

[0049] The specific components of Bacillus amyloliquefaciens, Trichoderma, Saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, Beauveria bassiana, and Metarhizium anisopliae can be 5 g / L, 5 g / L, 20 g / L, 20 g / L, 20 g / L, 2 g / L, and 2 g / L, respectively. Bacillus amyloliquefaciens, Trichoderma, Saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, Beauveria bassiana, and Metarhizium anisopliae are used to synergistically inhibit chitin synthesis in mites, decompose proteins in mite bodies, and have the following effects, respectively:

[0050] Bacillus amyloliquefaciens can produce various active metabolites during fermentation, such as antibacterial peptides and chitinase. Among them, antibacterial peptides can directly destroy the cell membrane structure of tracheal mites, leading to leakage of mite cell contents, thereby achieving the effect of killing mites. Chitinase can specifically degrade chitin components in the body wall of tracheal mites, weaken the defense ability of mites, and create conditions for the penetration of other active ingredients. At the same time, its metabolites can also inhibit the growth of harmful microorganisms in the bee colony, indirectly maintain the health of the bee intestine, and enhance the overall disease resistance of the bee colony.

[0051] Trichoderma is a typical biocontrol microorganism that can inhibit harmful microorganisms symbiotic in tracheal mites by competing for nutrients and space, destroy the microenvironment for the survival of tracheal mites, and decompose the secretions on the surface of tracheal mites and proteins in the body by secreting cellulase and protease, thereby interfering with the physiological metabolism of tracheal mites, leading to a decrease in tracheal mite activity and death. In addition, Trichoderma can also colonize and grow in the honeycomb environment, forming a biological barrier to reduce the probability of subsequent tracheal mite parasitism.

[0052] Saccharomyces cerevisiae as an auxiliary strain in the fermentation process, Saccharomyces cerevisiae can produce vitamins B group and amino acids and other nutrients through metabolism, which can be ingested by bees to supplement their nutrition, improve their immunity and resistance, and at the same time, the ethanol and carbon dioxide produced during fermentation can change the local microenvironment of the beehive, and have a certain repelling effect on bee mites, and the glucan in the cell wall of yeast can activate the immune system of bees and enhance their repair ability after being bitten by mites.

[0053] Photosynthetic bacteria can utilize light energy for metabolism to produce carotenoids and coenzyme Q10 and other antioxidant substances, which can be sprayed on the beehive, on the one hand, they can enter the body of bees through contact or ingestion, clear free radicals in the body of bees, and reduce oxidative stress damage caused by mite bites, on the other hand, photosynthetic bacteria can still survive in anaerobic environment, which can improve the microecological balance of the beehive (especially the gap of the brood nest), inhibit the growth of harmful anaerobic bacteria, and reduce the risk of bees being infected by mites.

[0054] Lactic acid bacteria are beneficial symbiotic bacteria in the intestines of bees, and exogenous addition can inhibit the colonization of harmful bacteria in the intestines through competitive exclusion, maintain the balance of intestinal flora, and produce lactic acid, acetic acid and other organic acids, which can not only reduce the PH value of the intestines of bees and enhance the digestive function, but also be excreted with feces to form an acidic environment on the surface of the beehive, which can inhibit mites, in addition, lactic acid bacteria can stimulate the immune system of bees to produce immunoglobulins and improve their resistance to viruses transmitted by mites.

[0055] Both Beauveria bassiana and Metarhizium anisopliae are specific mite-killing fungi against mites, and their spores can germinate into mycelium under suitable temperature and humidity after contacting the body surface of mites, the mycelium can penetrate the body wall of mites and enter the body, rapidly grow and reproduce by absorbing nutrients in the body of mites, and secrete toxins such as beauvericin and metarhizium toxin to destroy the internal organs of mites, eventually leading to the death of mites, and these two fungi are highly safe to bees, they cannot penetrate the body wall of bees and colonize in the body of bees, and only target mites, which has high target specificity.

[0056] The natural elements in the fermentation medium include inducers, selenium-rich yeast, nano zinc oxide, tea saponin and sugarcane molasses, which are used to enhance the immunity of bees and destroy the body wall of mites, and the effects of inducers, selenium-rich yeast, nano zinc oxide, tea saponin and sugarcane molasses are as follows:

[0057] Chitosan oligosaccharide, as a highly efficient inducer for microbial fermentation, can activate the metabolic pathways of bacteria such as Bacillus amyloliquefaciens and Trichoderma, promoting the synthesis of more antimicrobial peptides and chitinases, thus enhancing the acaricidal efficiency of fermentation products. Chitosan oligosaccharide itself also has acaricidal activity; its molecules can enter the body through the gaps in the body wall of the bee mite, bind to proteins in the mite cells, and disrupt protein structure and function, leading to metabolic disorders in the bee mite. Chitosan oligosaccharide can also be absorbed by bees, promoting the proliferation of intestinal mucosal cells and enhancing intestinal barrier function.

[0058] Taurine plays a dual regulatory role in fermentation systems. It can act as a signaling molecule to induce microbial strains (such as lactic acid bacteria and photosynthetic bacteria) to optimize metabolic pathways and increase the yield of beneficial metabolites. At the same time, as an essential sulfur-containing amino acid for bees, it can be directly utilized by bees to participate in the synthesis of antioxidant enzymes in bees, thereby enhancing their tolerance to bee bites and environmental stress. Taurine can also disrupt the ion balance in bee mites, leading to osmotic pressure disorders in mite cells and helping to improve the mite-killing effect.

[0059] Selenium-enriched yeast is a dual-function ingredient for nutritional fortification and synergistic acaricidal action. The organic selenium contained in selenium-enriched yeast can be ingested by bees and participate in the synthesis of glutathione peroxidase in bees. This enzyme can effectively remove harmful substances such as hydrogen peroxide produced by bee bites from varroa mites, reducing oxidative damage. At the same time, selenium can also inhibit the antioxidant system in varroa mites, reduce the mites' tolerance to acaricidal active substances, and enhance the acaricidal effect of other ingredients. Selenium-enriched yeast can also increase the selenium content in honey and increase the nutritional value of bee products.

[0060] The nano zinc oxide is modified with silane coupling agent KH-550, and has a nano-sized particle size of 20-50nm. The modified nano zinc oxide has a dual function of targeted acaricidal action and formulation stabilization. Its nano-sized particles can easily penetrate the body wall of the bee mite and enter the mite cell. After entering the mite cell, it releases zinc ions to destroy the DNA structure of the bee mite cell nucleus, inhibit cell division, and lead to the death of the bee mite. The modification with silane coupling agent KH-550 can improve the dispersibility of nano zinc oxide in fermentation broth, avoid agglomeration, ensure uniform contact with bee mites, and reduce irritation to the bee's body surface. Zinc ions can also inhibit the activity of proteases in bee mites, interfere with their nutrient absorption, and help achieve the acaricidal effect.

[0061] Tea saponin is a natural surfactant and acaricide. The hydrophilic and hydrophobic groups in its molecular structure can reduce the surface tension of the wax layer on the surface of the bee mite and destroy the integrity of the wax layer, making it easier for other acaricidal active ingredients (such as antimicrobial peptides and nano zinc oxide) to penetrate into the mite and improve the synergistic acaricidal efficiency. At the same time, tea saponin itself also has acaricidal effect. It can destroy the permeability of the bee mite cell membrane, causing the mite cells to dehydrate and die. Tea saponin has extremely low toxicity to bees and can form a protective film on the surface of the hive, reducing the entry of external pollutants into the hive.

[0062] Sugarcane molasses, as a carbon and nitrogen source and a stabilizer for fermentation, is the core foundation of the entire fermentation system. Its rich content of sucrose, glucose, and amino acids provides ample metabolic substrates for microorganisms such as Bacillus amyloliquefaciens and Saccharomyces cerevisiae, ensuring rapid proliferation of the strains and the synthesis of large quantities of active metabolites. The polysaccharides and pigments in molasses can increase the viscosity of the fermentation liquid, improve the stability of the formulation, and reduce the degradation of active ingredients during storage. The sweetness of molasses can also attract bees to the formulation, indirectly promoting the absorption of nutrients by bees.

[0063] Furthermore, the inducing agents include chitosan oligosaccharide and taurine, and the composition and content of chitosan oligosaccharide and taurine in the culture medium are as follows:

[0064] Chitosan oligosaccharide 4-6g / L

[0065] Taurine 19-21 g / L.

[0066] Furthermore, the contents of selenium-enriched yeast and nano-zinc oxide in the fermentation medium were as follows:

[0067] 3-8g / L of selenium-enriched yeast

[0068] Nano zinc oxide 1-3g / L.

[0069] Specifically, the contents of tea saponin and sugarcane molasses in the fermentation medium were as follows:

[0070] Tea saponin 19-21g / L

[0071] 98-101g / L of cane molasses

[0072] The specific components of sugarcane molasses, tea saponin, taurine, and chitosan oligosaccharide can be 100g / L, 20g / L, 20g / L, and 5g / L, respectively.

[0073] Specifically, the content of antimicrobial peptides in the compound fermentation metabolites is not less than 1.2 mg / mL, the content of organic acids is not less than 5.0 mg / mL, the photosynthetic bacteria are Rhodopseudomonas palustris, and the lactic acid bacteria are Lactobacillus plantarum (CGMCC 1.557).

[0074] A method for preparing a bee mite control agent based on a multi-element compound includes the following specific steps:

[0075] Step 1: Mix and dissolve 100g / L of sugarcane molasses, 20g / L of tea saponin, 20g / L of taurine, 5g / L of chitosan oligosaccharide, 3-8g / L of selenium-enriched yeast and 1-3g / L of nano zinc oxide, stir evenly, adjust the pH value, and prepare a fermentation culture medium.

[0076] Step 2: Activate and culture the following bacteria separately: Bacillus amyloliquefaciens (5g / L), Trichoderma (5g / L), Saccharomyces cerevisiae (20g / L), photosynthetic bacteria (20g / L), lactic acid bacteria (20g / L), Beauveria bassiana (2g / L), and Metarhizium anisopliae (2g / L). The activation and culture conditions are as follows: Bacillus amyloliquefaciens and Trichoderma were cultured on LB medium at 30℃ and 180 rpm for 12 h; Saccharomyces cerevisiae was cultured on YPD medium at 28℃ and 150 rpm for 16 h; photosynthetic bacteria were cultured anaerobically on photosynthetic bacteria medium at 30℃ and 2000 lux for 24 h; lactic acid bacteria were cultured anaerobically on MRS medium at 37℃ for 18 h; Beauveria bassiana and Metarhizium anisopliae were cultured on PDA medium at 28℃ for 48 h. Inoculate these bacteria into the fermentation medium from Step 1 according to their respective inoculation weight components.

[0077] Step 3: Aerobic fermentation of the components in the fermentation medium was carried out. The aerobic fermentation temperature, stirring speed, and aeration rate were 30℃, 200 rpm, and 1.0-1.5 vvm, respectively. The aerobic fermentation time was 24 hours. After the aerobic fermentation was completed, it was transferred to static anaerobic fermentation. The anaerobic fermentation temperature was 25℃, and the anaerobic fermentation time was 48 hours. During the fermentation process, the pH value was adjusted in real time and maintained between 5.5 and 6.5.

[0078] Step 4: After the pressurized oxygen fermentation is completed, the fermentation broth is centrifuged at 8000-10000 rpm for 15-20 minutes. The supernatant is then collected and filtered for sterilization using a 0.22 μm filtration membrane to obtain the composite fermentation broth, which is the stock solution for the bee mite control agent. When using the stock solution, it should be diluted 50-70 times. 0.1% xanthan gum can be added as a stabilizer to the diluted solution. Then, a bee mite control efficacy test is conducted, which includes:

[0079] Ten bee colonies with similar health status and similar bee mite infection rates were selected, with approximately 5,000 bees in each colony. All colonies were kept in standard hives of the same size and in the same environment. Then, the bee mite control agent stock solution prepared in this invention, commercial formic acid solution (85% effective ingredient content, a conventional chemical agent for bee mite control) and sterile water (blank control) were prepared.

[0080] Then, the 10 bee colonies were randomly divided into 3 groups: 3 colonies in the experimental group, 3 colonies in control group 1 (chemical agent group), and 4 colonies in control group 2 (blank control group), and then the experimental operation was carried out.

[0081] During the experimental group, the original solution of the bee mite control agent of this invention was first taken and diluted with sterile water at a ratio of 50 times. The solution was then sprayed evenly on the inside of the beehive, the surface of the hive, and the area where the bees lived using an electric sprayer. The amount of sprayed per beehive was 120 mL to ensure that the agent was evenly covered.

[0082] In control group 1 (chemical agent group), commercially available formic acid solution was taken and diluted with sterile water to an effective ingredient content of 5% according to the concentration recommended in the product instructions. The bee colonies were sprayed using the same spraying method and spraying amount as the experimental group.

[0083] Control group 2 (blank control group) was treated with sterile water only, and the bee colonies were sprayed with the same spraying method and amount as the experimental group.

[0084] After all spraying is completed, observe the bees for 6 hours, 12 hours, 24 hours, 48 ​​hours, and 72 hours. Detect the mortality rate of varroa mites and the survival rate of bees in each group of bee colonies using the following specific methods:

[0085] To detect the mortality rate of Varroa mites, three combs were randomly selected from each colony, and 100 bees were randomly selected from each comb. A magnifying glass was used to observe and count the number of live and dead mites on the bees' bodies and in the comb crevices. The mortality rate was calculated using the following formula:

[0086] .

[0087] Bee survival rate was determined by counting the total number of bees in each colony before spraying, counting the number of surviving bees at each detection time point, and calculating the bee survival rate using the following formula:

[0088] .

[0089] The results of the varroa mite mortality rate and bee survival rate tests are shown in Tables 1 and 2 below:

[0090] Detection time Experimental group Control group 1 Control group 2 6h 68.5±3.2 45.2±2.8 5.3±1.1 12h 89.3±2.5 62.7±3.1 7.8±1.5 24h 100.0±0.0 78.1±2.3 9.5±1.2 48h 100.0±0.0 82.5±2.6 11.2±1.4 72h 100.0±0.0 83.3±2.1 12.6±1.3

[0091] Table 1: Comparison of Varroa mite mortality rates at different time points in each bee colony group (%)

[0092] Detection time Experimental group Control group 1 Control group 2 6h 99.2±0.5 95.3±1.2 99.5±0.3 12h 98.8±0.6 93.1±1.5 99.3±0.4 24h 98.5±0.7 91.5±1.8 99.1±0.5 48h 98.2±0.8 89.8±2.1 98.9±0.6 72h 97.9±0.9 88.2±2.3 98.7±0.7

[0093] Table 2: Comparison of bee survival rates at different time points in each group of bee colonies (%)

[0094] As shown in Table 1, the mortality rate of Varroa mites in the experimental group reached 68.5% 6 hours after spraying, rose to 89.3% 12 hours, and reached 100% 24 hours. The mortality rate remained at 100% for the following 48 and 72 hours, indicating rapid and long-lasting mite control. In contrast, the mortality rate of Varroa mites in control group 1 (chemical agent group) was only 78.1% 24 hours and only reached 83.3% even at 72 hours, showing significantly lower mite control efficiency than the experimental group. In control group 2 (blank control group), the mortality rate of Varroa mites remained below 13% throughout the entire testing period, indicating virtually no mite control effect.

[0095] As shown in Table 2, the bee survival rate in the experimental group remained above 97.9% throughout the entire testing period, with no significant difference from the blank control group. This indicates that the bee mite control agent of the present invention is non-toxic to bees and will not adversely affect their survival. In contrast, the bee survival rate in control group 1 (chemical agent group) gradually decreased with the extension of the testing time, dropping to 88.2% at 72 hours, which was significantly lower than that in the experimental group and the blank control group. This suggests that commercially available formic acid solution has a certain degree of toxicity to bees and can harm bee colonies.

[0096] Therefore, the multi-element compound-based bee mite control agent of the present invention has the advantages of high mite killing efficiency, rapid onset of action, long-lasting effect and safety and non-toxicity to bees, which is significantly better than traditional chemical acaricides and is suitable for promotion and application in beekeeping.

[0097] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-element compound-based bee mite control agent, characterized in that: The mixture includes complex fermentation metabolites and natural elements in the fermentation medium. The complex fermentation metabolites include *Bacillus amyloliquefaciens*, *Trichoderma*, *Saccharomyces cerevisiae*, photosynthetic bacteria, lactic acid bacteria, *Beauveria bassiana*, and *Metarhizium anisopliae*, with the following inoculation weight composition: Bacillus amyloliquefaciens 4-6 g / L Trichoderma 4-6g / L brewing yeast 18-21g / L Photosynthetic bacteria 18-21g / L Lactic acid bacteria 18-21g / L Beauveria bassiana 1-3g / L Metarhizium anisopliae 1-3g / L; The Bacillus amyloliquefaciens, Trichoderma, Saccharomyces cerevisiae, photosynthetic bacteria, lactic acid bacteria, Beauveria bassiana, and Metarhizium anisopliae are used to synergistically inhibit chitin synthesis in mites and decompose proteins in mites. The natural elements in the fermentation medium include an inducer, selenium-enriched yeast, nano zinc oxide, tea saponin, and sugarcane molasses. The inducer, selenium-enriched yeast, nano zinc oxide, tea saponin, and sugarcane molasses are used to enhance the immunity of bees and destroy the body wall of mites.

2. The bee mite control agent based on a multi-element compound according to claim 1, characterized in that: The inducing agent comprises chitosan oligosaccharide and taurine, and the composition and content of chitosan oligosaccharide and taurine in the culture medium are as follows: Chitosan oligosaccharide 4-6g / L Taurine 19-21 g / L.

3. The bee mite control agent based on a multi-element compound according to claim 1, characterized in that: The contents of the selenium-enriched yeast and nano-zinc oxide in the fermentation medium are as follows: 3-8g / L of selenium-enriched yeast Nano zinc oxide 1-3g / L.

4. The bee mite control agent based on a multi-element compound according to claim 1, characterized in that: The contents of tea saponin and sugarcane molasses in the fermentation medium are as follows: Tea saponin 19-21g / L Sugarcane molasses 98-101g / L.

5. The bee mite control agent based on a multi-element compound according to claim 1, characterized in that, The content of antimicrobial peptides in the compound fermentation metabolites is not less than 1.2 mg / mL, the content of organic acids is not less than 5.0 mg / mL, the photosynthetic bacteria is Rhodopseudomonas palustris, and the lactic acid bacteria is Lactobacillus plantarum.

6. A method for preparing a bee mite control agent based on a multi-element composite, characterized in that: The specific steps include the following: Step 1: Mix and dissolve 100g / L of sugarcane molasses, 20g / L of tea saponin, 20g / L of taurine, 5g / L of chitosan oligosaccharide, 3-8g / L of selenium-enriched yeast and 1-3g / L of nano zinc oxide, stir evenly, adjust the pH value, and prepare a fermentation culture medium. Step 2: After activating and culturing Bacillus amyloliquefaciens (5g / L), Trichoderma (5g / L), Saccharomyces cerevisiae (20g / L), photosynthetic bacteria (20g / L), lactic acid bacteria (20g / L), Beauveria bassiana (2g / L), and Metarhizium anisopliae (2g / L), respectively, inoculate them into the fermentation medium in Step 1 according to the inoculation weight components. Step 3: Perform aerobic fermentation on the components in the fermentation medium. After the aerobic fermentation is completed, transfer to static anaerobic fermentation. Step 4: After the pressurized oxygen fermentation is completed, the fermentation broth is centrifuged, and the supernatant is collected. Then, the supernatant is filtered with a filter membrane to remove bacteria, resulting in a compound fermentation broth, which is the stock solution of the bee mite control agent. Then, the bee mite control effect is tested.

7. The method for preparing a bee mite control agent based on a multi-element composite according to claim 6, characterized in that: In step three, the aerobic fermentation temperature, stirring speed, and aeration rate are 30℃, 200rpm, and 1.0-1.5vvm, respectively, and the fermentation time is 24h.

8. The method for preparing a bee mite control agent based on a multi-element composite according to claim 7, characterized in that: The fermentation temperature for the oxygen-controlled fermentation in step three is 25°C, and the fermentation time is 48 hours.

9. The method for preparing a bee mite control agent based on a multi-element composite according to claim 8, characterized in that: The centrifugation speed in step four is 8000-10000 rpm, and the centrifugation time is 15-20 min.

10. The method for preparing a bee mite control agent based on a multi-element composite according to claim 9, characterized in that: The filter membrane in step four has a pore size of 0.22 μm.

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