Cnaphalocrocis medinalis sex pheromone microcapsule as well as preparation method and application thereof
Through microcapsule technology, the pheromones of rice leaf rolling borer were embedded, which solved the problem of rapid volatility and easy oxidation of pheromones, achieved stable release and efficient prevention and control, reduced environmental pollution and prevention and control costs, and controlled the pheromones population of rice leaf rolling borer.
Patent Information
- Application Number
- CN202510657944.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-08-26
AI Technical Summary
The pheromones of rice leaf rolling borer have fast volatility and short induction period. The existing chemical control methods lead to environmental pollution and pest resistance. Insect pheromones are easily oxidized and decomposed in the air, making them difficult to effectively utilize.
Microcapsule technology was used to embed the rice leaf rolling pheromones (Z)-11-octadecene, (Z)-13-octadecene, (Z)-11-octadecene and (Z)-13-octadecene were embedded in the microcapsule wall material made of gelatin and gum arabic. Microcapsules were prepared by phase separation method and interface polymerization method to protect the pheromones from oxidation and prolong the release time.
It improves the stability and effectiveness of pheromone, reduces the cost of prevention and control, reduces the risk of environmental pollution, extends the release time of pheromone, improves the efficiency of insect luring, and interferes with the mating of rice leaf rolling borer through the mystery method to control the population.
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Figure CN120530964A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of rice leaf folder pheromone embedding and sustained release, and in particular to a rice leaf folder pheromone microcapsule and a preparation method and application thereof. Background Art
[0002] The rice leaf roller reproduces in my country from one to eleven generations, with a maximum of two generations in Northeast China. From north to south, from the middle and lower reaches of the Yangtze River to Lingnan, it typically lasts around four generations, and in southern Hainan, it typically lasts around ten generations. The first through fifth generations typically reproduce in June, July, August, September, and mid-October each year. In terms of damage, the first and fifth generations are relatively infrequent, while the second and fifth generations are generally more numerous and pose a greater threat to rice crops.
[0003] Currently, there are five methods for controlling the rice leaf folder: chemical control, biological control, agricultural control, physical control, and genetic control. Currently, chemical control is the mainstream method for controlling the rice leaf folder. Its advantages include ease of use, mature technology, and effective control. However, chemical control also has significant disadvantages. Excessive use of chemical pesticides can lead to chemical residues that contaminate precious water and land resources, damage the ecological environment of farmland, and ultimately accumulate in the human body through food crops and drinking water, posing a threat to human health. For example, dieldrin is particularly harmful to bees, and if accumulated in large quantities in the human body, it can cause serious poisoning. Excessive chemical residues in food crops not only harm human health but also damage the international reputation of my country's agricultural production. The use of chemical pesticides is inseparable from the use of application machinery, but there is still a significant gap between my country and developed countries in terms of specialized agricultural machinery, further hindering the efficient use of chemical pesticides. Currently, my country's chemical pest control efforts focus solely on pesticide types and application rates, without understanding the principles of scientific application. Some regions are excessively focused on rice yields, disregarding the region's reasonable tolerance for chemical pollution, leading to excessive pesticide use. Data shows that my country's pesticide utilization rate is 15-25%, while developed countries can achieve an effective utilization rate of 55-65%. This significantly lower effective utilization rate is a significant improvement, and increased pesticide use will inevitably lead to ecological damage.
[0004] Chemical control can also lead to pest resistance, significantly reducing the effectiveness of chemical pesticides. This forces humans to increase research and development funding to synthesize new chemical pesticides, creating a vicious cycle. In recent years, rice leaf rollers have been found in some areas to develop resistance to pesticides such as emamectin benzoate and chlorfenapyr. Their larvae have also shown resistance to chlorpyrifos and methyl parathion, indicating that certain pest populations in my country are developing resistance to various chemical pesticides, further reducing their effectiveness.
[0005] Insect pheromones are mostly composed of volatile chemicals that easily oxidize and deteriorate when exposed to air, making it difficult for them to exert their full potential. However, microencapsulation can effectively protect pheromones. Through appropriate processing, insect pheromones can be prepared into attractant cores and encapsulated within them, minimizing pheromone oxidation and degradation. More importantly, it can also prolong the pheromone's release period. Microencapsulation methods are mainly categorized into physical, chemical, and physicochemical methods. Physical methods, such as centrifugal extrusion, film formation, electrostatic deposition, and inclusion methods, produce microcapsules without molecular modifications. Chemical methods, however, modify the molecular state through chemical means, causing them to aggregate and encapsulate the target compound. Physicochemical methods, however, modify the external reaction environment during the reaction phase—namely, temperature, pH, and electrolytes in the solution—ultimately achieving the goal of forming a film of a polymer dissolved in the reaction system that encapsulates the target compound and subsequently precipitates it. Currently, the two main methods for preparing sex pheromone microcapsules are phase separation and interfacial polymerization. Phase separation involves dissolving two or more oppositely charged polymers in a system. By altering the temperature, pH, or concentration of the solution, the various materials interact and precipitate, further reacting to form microcapsules. Encapsulating sex pheromones in microcapsules is a new approach for developing rice leaf roller sex pheromones. Summary of the Invention
[0006] The present invention aims to address the problems of rapid volatility and short attraction period of rice leaf folder sex pheromone substances in the prior art, and to provide a rice leaf folder sex pheromone microcapsule and a preparation method thereof. The invention improves the stability and long-lasting effect of the rice leaf folder sex pheromone by embedding the rice leaf folder sex pheromone in a carrier. The microcapsule sustained-release carrier prepared by the method contains the rice leaf folder sex pheromone components: (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol.
[0007] In order to achieve the above object, the technical solution provided by the present invention is as follows:
[0008] A rice leaf folder sex pheromone microcapsule comprises a microcapsule wall material and a microcapsule core material; the microcapsule wall material comprises gelatin and gum arabic; the microcapsule core material comprises the rice leaf folder sex pheromone and liquid paraffin; the rice leaf folder sex pheromone is composed of (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol, and the mass ratio thereof is (1-2):(10-15):(2-3):(4-6), preferably 1:10:2:4.
[0009] The mass ratio of the gelatin to the gum arabic is (1-1.6):(1-1.6), preferably 1:1.
[0010] The ratio of the mass of the sex pheromone of rice leaf folder to the sum of the mass of gelatin and gum arabic is 1:10-60.
[0011] Wherein, the concentration of the rice leaf folder sex pheromone in the liquid paraffin is 0.5-1 g / L.
[0012] The chemical purity of the (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol are all greater than 85% (weight percentage), and the stereoisomeric purity is all greater than 90% (weight percentage).
[0013] The present invention also provides a method for preparing the rice leaf folder sex pheromone microcapsules, comprising the following steps:
[0014] (1) Preparation of prepolymer solution: gelatin and gum arabic are added to water and stirred and dissolved at 70-80°C to obtain a mixed gelatin solution; wherein the water is preferably water at 70-80°C.
[0015] (2) Emulsification stage: adding the rice leaf folder sex pheromone to the liquid paraffin to obtain a rice leaf folder sex pheromone liquid paraffin solution, adding the mixed glue solution obtained in step (1) and the polyvinyl alcohol aqueous solution thereto, stirring at 40-45° C. to obtain a rice leaf folder sex pheromone mixed solution;
[0016] (3) Encapsulation stage: The pH of the rice leaf folder sex pheromone mixture obtained in step (2) is adjusted to 4.0 to 4.5, preferably 4.3, with an acetic acid aqueous solution, and stirred. During the stirring process, emulsified silicone oil is added for defoaming, and the rice leaf folder sex pheromone mixture is condensed to form microcapsule aggregates. In this step, acetic acid is used to acidify the rice leaf folder sex pheromone mixture to cause it to condense to form microcapsule aggregates.
[0017] (4) Curing and forming stage: Add water to the microcapsule agglomerates obtained in step (3), mix thoroughly, let stand and cool to room temperature, stir at 6-10°C, add glutaraldehyde aqueous solution, mix thoroughly, add NaOH aqueous solution to adjust the pH to 9.0-9.5, let stand at 40-50°C for 15-20 minutes, filter, collect the solid matter, wash with anhydrous ethanol and distilled water in sequence, and dry to obtain a white solid powder of rice leaf roller sex pheromone microcapsules. Glutaraldehyde is used for curing in this step to promote further curing and crosslinking of the microcapsules.
[0018] In step (1), in the mixed gelatin solution, the mass fraction of the gelatin is 2.5-4%, preferably 2.5% or 4%, and the mass fraction of the gum arabic is 2.5-4%, preferably 2.5% or 4%.
[0019] In step (2), the concentration of the rice leaf folder sex pheromone in the rice leaf folder sex pheromone liquid paraffin solution is 0.5-1 g / L; in the rice leaf folder sex pheromone mixed solution, the ratio of the mass of the rice leaf folder sex pheromone to the sum of the mass of gelatin and gum arabic is 1:10-60; the mass fraction of the polyvinyl alcohol aqueous solution is 1-2%; and the amount of the polyvinyl alcohol aqueous solution added is 1-5% of the sum of the volume of the rice leaf folder sex pheromone liquid paraffin solution and the mixed gelatin solution.
[0020] In steps (2) and (3), the stirring speed is 650-700 r / min and the time is 30-35 min. The stirring speed should not be too fast or too slow. Too fast will easily lead to agglomeration in the microcapsule formation stage, and too slow will easily lead to uneven stirring of the solution and uneven distribution of sex pheromones. In step (4), the stirring speed is 400-450 r / min and the time is 30-35 min.
[0021] In step (3), the concentration of the acetic acid aqueous solution is 10-15% v / v, and the amount of the emulsified silicone oil added is based on the standard of achieving the purpose of defoaming.
[0022] In step (4), the amount of water added is 1 to 1.2 times the volume of the microcapsule agglomerates; the concentration of the glutaraldehyde aqueous solution is 1.5 to 2 mg / mL, and the amount added is 0.1 to 0.2 times the sum of the volumes of the microcapsule agglomerates and the water; the filtration is performed using a Buchner funnel and filter paper with a pore size of 100 nm; the drying is performed under vacuum at 20 to 25° C. for 30 to 40 hours; and the concentration of the NaOH aqueous solution is 0.08 to 0.12 g / mL.
[0023] The method for storing the rice leaf folder sex pheromone microcapsules is as follows: wrapping and sealing the microcapsules with tin foil, placing the microcapsules in a glass bottle, tightening the bottle cap, and sealing the microcapsule away from light.
[0024] The present invention also claims the use of the rice leaf folder sex pheromone microcapsules in controlling rice leaf folders. The microcapsules can be used for trapping, killing, and disorienting rice leaf folders, and have high economic value and ecological benefits for agricultural production.
[0025] Beneficial effects:
[0026] (1) Using the microcapsule preparation process of the sex pheromone of rice leaf folder of the present invention, the microcapsule coverage rates of the four components of the sex pheromone of rice leaf folder, (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol, were 85-96%, 86-94%, 82-93% and 85-96%, respectively, indicating that the sex pheromone of rice leaf folder can be well microencapsulated by the complex coacervation method of the present invention.
[0027] (2) The present invention encloses the sex pheromone of rice leaf folder in microcapsules, limits the release of the sex pheromone, effectively blocks light, air and moisture, reduces the rate of oxidative decomposition of the active ingredient, ensures that the sex pheromone is released at a relatively stable rate, and ensures a long sustained-release period, which has a significant effect on the long-lasting and stable release of the sex pheromone of rice leaf folder, solves the problem of instability and volatility of the sex pheromone of rice leaf folder in agricultural applications, reduces the frequency of replacing the lure core, and reduces the cost of preventing and controlling the rice leaf folder. In the preparation process of the rice leaf folder sex pheromone microcapsules of the present invention, the retention rate of the four components of the rice leaf folder sex pheromone, (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol, and (Z)-13-octadecenol, in the microcapsules is between 62% and 75%. Under the same conditions, compared with the retention rate of polyethylene tube slow-release carriers on the market, the microcapsules significantly prolong the release time of the rice leaf folder sex pheromone. In addition, the release efficiency of the microcapsules of the four components of the rice leaf folder sex pheromone, (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol, and (Z)-13-octadecenol, is relatively balanced in experiments, and the four components are released in a constant ratio, thereby improving the insect attracting efficiency.
[0028] (3) The rice leaf folder sex pheromone microcapsules of the present invention have good insect attracting efficiency without requiring high purity of the active ingredients of the rice leaf folder sex pheromones, thereby reducing the control cost of the rice leaf folder and effectively controlling the rice leaf folder.
[0029] (4) The rice leaf folder sex pheromone microcapsules of the present invention can also be used in agricultural production to interfere with the mating of rice leaf folders by the disorientation method, thereby achieving the purpose of causing an imbalance in the number of males and females in the rice leaf folder population and controlling its population size.
[0030] (5) The preparation process of the rice leaf folder sex pheromone microcapsules of the present invention is relatively simple, the wall material is easy to obtain, and the raw materials are non-toxic and biodegradable. Compared with chemical control methods, the use of the microcapsules of the present invention for biological control of rice leaf folders is greener and friendlier to the ecological environment, and greatly reduces environmental health risks. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.
[0032] Figure 1 This is a scanning electron microscope image of the rice leaf folder sex pheromone microcapsule prepared in Example 1.
[0033] Figure 2 This is a scanning electron microscope image of the rice leaf folder sex pheromone microcapsule prepared in Example 2.
[0034] Figure 3 This is a scanning electron microscope image of the rice leaf folder sex pheromone microcapsule prepared in Example 3.
[0035] Figure 4 This is a dynamic curve diagram of the release rate of the four sex pheromone components in the rice leaf folder sex pheromone microcapsule M1 measured in Example 5.
[0036] Figure 5 This is a dynamic curve diagram of the release rate of the four sex pheromone components in the rice leaf folder sex pheromone microcapsule M2 measured in Example 5.
[0037] Figure 6 This is a dynamic curve diagram of the release rate of the four sex pheromone components in the rice leaf folder sex pheromone microcapsule M3 measured in Example 5.
[0038] Figure 7 This is the device for trapping rice leaf folder in Example 6. DETAILED DESCRIPTION
[0039] The present invention is further described below with reference to the following examples. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.
[0040] Specific techniques or conditions not specified in the examples were carried out according to those described in the literature in the field or according to the product instructions. Reagents or instruments used without manufacturer specified were all conventional products available through regular channels.
[0041] The present invention further conducts extensive research on the sex pheromone components of the rice leaf folder by utilizing single gland extraction and gas chromatography analysis technology, and determines that the four main components of the sex pheromone of the rice leaf folder are (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol, and that a ratio close to 1:10:2:4 can more efficiently reflect the state of the rice leaf folder's courtship call in the field.
[0042] Example 1
[0043] Preparation of rice leaf folder sex pheromone microcapsules M1:
[0044] (1) Preparation of prepolymer solution: Place 1 g of gum arabic and 1 g of gelatin in two 200 mL beakers, add 40 mL of 70°C distilled water to each beaker, heat the beakers in a water bath at 70-80°C, and slowly stir until the gelatin and gum arabic are dissolved. Pour the two into a 500 mL beaker and mix well. Let stand at (20 ± 1)°C for 30 min to obtain 80 mL of mixed gum solution.
[0045] (2) Emulsification stage: 0.15 mg of (Z)-11-octadecenal, 1.5 mg of (Z)-13-octadecenal, 0.3 mg of (Z)-11-octadecenol and 0.6 mg of (Z)-13-octadecenol were weighed, mixed and added to 5 mL of liquid paraffin to prepare a liquid paraffin solution of rice leaf folder sex pheromone, which was added to the beaker in step (1) and mixed evenly with the mixed gum solution. Then, 3 mL of polyvinyl alcohol aqueous solution (1 wt %) was added to the beaker, and the beaker was placed on an electromagnetic stirrer and stirred at 45° C. and 650 r / min for 30 min to obtain a rice leaf folder sex pheromone mixture. The chemical purity of the four components ((Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol) in the sex pheromone of rice leaf folder is greater than 93%, and the purity of the stereoisomers is greater than 90%.
[0046] (3) Encapsulation stage: 10% v / v acetic acid aqueous solution was added dropwise to the rice leaf folder sex pheromone mixture obtained in step (2) to adjust its pH to 4.3, and stirred at 650 r / min for 30 min to allow the rice leaf folder sex pheromone mixture to condense to form microcapsule aggregates. 1 g of emulsified silicone oil was added during the stirring process to defoam.
[0047] (4) Curing stage: Add an equal volume of distilled water to the microcapsule agglomerates obtained in step (3), stir and mix uniformly, let stand and cool to room temperature, then place the beaker in an ice bath and continue stirring at 400 rpm for 30 minutes, keeping the temperature at 6-10°C during stirring. Then add 15 mL of glutaraldehyde aqueous solution (1.8 mg / mL), stir and mix uniformly, and then adjust the pH to about 9.0 with 0.1 g / mL NaOH aqueous solution. Place the beaker in a water bath, slowly raise the temperature to 40°C, and let stand for 15 minutes to promote further curing of the microcapsule agglomerates.
[0048] (5) Forming stage: The solidified microcapsule aggregates were diluted to 500 mL with distilled water and filtered using a Buchner filter. The solid retentate was washed three times with distilled water and anhydrous ethanol to obtain microcapsules. Finally, the powdered rice leaf roller sex pheromone microcapsules were dried in a vacuum dryer at a temperature of 20-25°C for 30-40 hours.
[0049] Example 2
[0050] The rice leaf folder sex pheromone microcapsules M2 were prepared in the same manner as the preparation method of M1 in Example 1, except that the amount of gum arabic and gelatin used in the preparation of the prepolymer solution in step (1) was 2.5 g.
[0051] Example 3
[0052] The rice leaf folder sex pheromone microcapsules M3 were prepared in the same manner as the preparation method of M1 in Example 1, except that the amount of gum arabic and gelatin used in the preparation of the prepolymer solution in step (1) was 5 g.
[0053] Figure 1 、 Figure 2 and Figure 3 The figures are scanning electron microscope images of the rice leaf folder sex pheromone microcapsules prepared in Examples 1 to 3, respectively. The microcapsules are in the shape of regular spheres.
[0054] Example 4
[0055] The embedding rate and encapsulation rate of each component of the rice leaf folder sex pheromone microcapsules M1, M2 and M3 prepared in Examples 1 to 3 were tested.
[0056] Embedding efficiency test method: accurately weigh 0.2g (S T The microcapsule sample (accurate to 0.0001g) was ground into powder and transferred to a small beaker. Ultrasonic extraction with n-hexane was performed 3 times, with each ultrasonic oscillation lasting 1min. The sample was allowed to stand for 15min, concentrated with nitrogen blow-through, dehydrated with anhydrous sodium sulfate, and diluted to 5mL with n-hexane. The sex pheromone quality A was determined by gas chromatography. T , and calculate the microcapsule embedding rate according to the formula.
[0057] Encapsulation efficiency test method: Accurately weigh 0.2g (accurate to 0.0001g) of microcapsule sample in a small beaker, extract with n-hexane three times, ultrasonically oscillate for 30s each time, add 50μL / mL sex pheromone solution as internal standard, and adjust the volume to 5mL with n-hexane. Gas chromatography is used to detect the quality of sex pheromones on the surface of microcapsules. s , and the microcapsule encapsulation efficiency was calculated according to the formula.
[0058]
[0059] Among them, A T is the mass of pheromone in microcapsule sample (mg), S T is the mass of the microcapsule sample (g), S0 is the total mass of the microcapsules prepared in Example 1, 2 or 3 (g), A0 is the mass of the sex pheromone used in preparing the microcapsules in Example 1, 2 or 3 (mg), and A s is the mass of sex pheromone on the surface of the microcapsule sample.
[0060] Table 1 Covering rate and retention rate of rice leaf roller sex pheromone microcapsules prepared in Examples 1 to 3
[0061]
[0062]
[0063] The results show that the embedding rate of the rice leaf folder sex pheromone microcapsules prepared by the preparation method of the present invention is as high as 97%, and the encapsulation rate is as high as 72%.
[0064] Example 5
[0065] The release rates of the various components of the rice leaf folder sex pheromone microcapsules M1, M2 and M3 prepared in Examples 1 to 3 were tested.
[0066] 2g of rice leaf folder sex pheromone microcapsules M1, M2, and M3 were weighed and placed in wide-mouth bottles. The bottles were then opened and released. Volatile pheromone vapor was collected using an atmospheric sampler (QC-1S) in a room at 24-26°C, 50-80% relative humidity, and a wind speed of 20 cm / sec. The inlet of the atmospheric sampler (QC-1) was connected to a sampling tube via Teflon tubing. The adsorption column Porapak Q (Waters / WAT027060) was filled into the sampling tube at 150mg / tube. The adsorbent was aged at 200°C for 2h before use. Sampling was continued at a gas flow rate of 100mL / min for 30min. Immediately after treatment, the adsorbent was eluted with chromatographically pure n-hexane. The eluate was collected in a 4mL vial. Samples were collected every two days.
[0067] The contents of the four components in the eluent samples were determined using a 7890A-GC gas chromatograph (Agilent). A 7683B series autosampler was used, with nitrogen as the carrier gas and splitless injection (valve opening after 0.75 min). The detector was a flame ionization detector (FID). The chromatographic column was an HP-5 capillary column (30 mm × 0.25 mm, 0.25 μm). The inlet temperature was 200°C, the detector temperature was 250°C, the initial temperature was 40°C, the temperature was held for 5 minutes, then the temperature was increased to 200°C at a rate of 10°C / min and held for 5 minutes. Nitrogen was used as the carrier gas, and the injection volume was 1 μL. Data acquisition and analysis were performed using Agilent Chemstation software. Qualitative determination was based on chromatographic retention time, and quantification was performed using an external standard method.
[0068] The release rates of the sex pheromone components of rice leaf roller sex pheromone microcapsules M1, M2 and M3 are as follows: Figure 4 、 Figure 5 and Figure 6 As shown, the results show that the sustained-release effect of M1 is better than that of M2 and M3. M1 still has a sustained-release effect of 20 μg / day after 50 days, which is significantly better than M2 and M3. Through comprehensive evaluation of sustained-release effect, embedding efficiency, and coverage rate, it was found that the rice leaf roller sex pheromone microcapsules prepared in Example 1 have the best effect. The more stable the release of rice leaf roller sex pheromone in the microcapsule, the longer the sex pheromone is retained. In other words, the slower and more stable the release rate of rice leaf roller sex pheromone, the longer the duration. Gelatin-arabic gum, as a carrier of rice leaf roller sex pheromone, can ensure the uniform and slow release of sex pheromone, and can protect the sex pheromone components from oxidation and decomposition by environmental factors such as air and light, thereby maintaining the long-lasting biological activity of the sex pheromone.
[0069] Example 6
[0070] This example compares the trapping efficiency of Cnaphalocrocis medinalis by added and unadded Cnaphalocrocis medinalis sex pheromone microcapsules for Cnaphalocrocis medinalis. In this embodiment, the added rice leaf folder sex pheromone microcapsules refer to microcapsules prepared by mixing and encapsulating four sex pheromone components ((Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol) in a mass ratio of 1:10:2:4 in the same microcapsule (i.e., the microcapsules prepared in Example 2). The unadded rice leaf folder sex pheromone microcapsules refer to four sex pheromone components being respectively encapsulated in four microcapsules to prepare four microcapsules. When used, the four microcapsules are mixed and used according to the mass ratio of the four sex pheromone components of 1:10:2:4. Except that only one of the four sex pheromone components is added in the emulsification stage of step (2), the other steps are the same as the preparation method of Example 2.
[0071] Rice leaf roller trapping experimental method:
[0072] like Figure 7 As shown, the trapping experiment used a Y-shaped olfactometer. The side arms of the olfactometer were connected to the insect storage bottle, odor source bottle, humidifier, air filter, flow meter, power pump, and other components. All components were connected using silicone tubing, with the side walls forming a 90° angle. Before the experiment began, all components were sealed, the power pump was turned on, and the air in the device was exhausted. The airflow rate within the device was adjusted to 150 mL / min. Other parameters, such as room temperature and humidity, were controlled at 25 ± 2°C and 75% to 85%.
[0073] Rice leaf folder pupae were placed in glass finger-shaped tubes and waited for them to emerge. A total of 110 male moths, all emerging at the same time and with intact antennae and strong vitality, were selected. Accurately weighed microcapsules containing rice leaf folder sex pheromones (with or without the addition) were placed into one arm of the trap. An equal amount of microcapsules without sex pheromones were placed in the other arm as a control.
[0074] Table 2 Number of rice leaf folders trapped by microcapsules with and without added pheromone
[0075]
[0076] The experimental results show that the added rice leaf folder sex pheromone microcapsules are much more efficient in trapping rice leaf folders than the unadded rice leaf folder sex pheromone microcapsules.
[0077] The present invention provides a rice leaf folder sex pheromone microcapsule, as well as a preparation method and application thereof. There are many methods and approaches to implement this technical solution. The above is only a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also considered to be within the scope of protection of the present invention. Any components not specified in this embodiment may be implemented using existing technologies.
Claims
1. A rice leaf folder sex pheromone microcapsule, characterized in that: The invention comprises a microcapsule wall material and a microcapsule core material; the microcapsule wall material comprises gelatin and gum arabic; the microcapsule core material comprises rice leaf folder sex pheromone and liquid paraffin; the rice leaf folder sex pheromone is composed of (Z)-11-octadecenal, (Z)-13-octadecenal, (Z)-11-octadecenol and (Z)-13-octadecenol, and the mass ratio thereof is (1-2):(10-15):(2-3):(4-6).
2. The rice leaf folder sex pheromone microcapsule according to claim 1, characterized in that The mass ratio of the gelatin to the gum arabic is (1-1.6):(1-1.6).
3. The rice leaf folder sex pheromone microcapsule according to claim 1, characterized in that The ratio of the mass of the rice leaf folder sex pheromone to the sum of the mass of gelatin and gum arabic is 1:1000-2000.
4. The rice leaf folder sex pheromone microcapsule according to claim 1, characterized in that The concentration of the rice leaf folder sex pheromone in the liquid paraffin is 0.5-1 g / L.
5. The method for preparing the rice leaf folder sex pheromone microcapsules according to any one of claims 1 to 4, comprising the following steps: (1) Preparation of prepolymer solution: Add gelatin and gum arabic into water and stir to dissolve at 70-80°C to obtain a mixed gel solution; (2) Emulsification stage: adding the rice leaf folder sex pheromone to the liquid paraffin to obtain a rice leaf folder sex pheromone liquid paraffin solution, adding the mixed glue solution obtained in step (1) and the polyvinyl alcohol aqueous solution thereto, stirring at 40-50° C. to obtain a rice leaf folder sex pheromone mixed solution; (3) Encapsulation stage: the pH of the rice leaf folder sex pheromone mixture obtained in step (2) is adjusted to 4.0-4.5 with an acetic acid aqueous solution, and stirred. During the stirring process, emulsified silicone oil is added for defoaming, and the rice leaf folder sex pheromone mixture is condensed to form microcapsule aggregates; (4) Curing and forming stage: add water to the microcapsule agglomerates obtained in step (3), stir at 6-10°C, add glutaraldehyde aqueous solution, mix well, add NaOH aqueous solution to adjust the pH to 9.0-9.5, let stand at 40-45°C for 15-20 minutes, filter, collect the solid matter, wash with anhydrous ethanol and distilled water in sequence, and dry to obtain the product.
6. The preparation method according to claim 5, characterized in that In step (1), in the mixed gelatin solution, the mass fraction of the gelatin is 2.5-4%, and the mass fraction of the gum arabic is 2.5-4%.
7. The preparation method according to claim 5, characterized in that In step (2), the concentration of the rice leaf folder sex pheromone in the rice leaf folder sex pheromone liquid paraffin solution is 0.5-1 g / L; in the rice leaf folder sex pheromone mixed solution, the ratio of the mass of the rice leaf folder sex pheromone to the sum of the mass of gelatin and gum arabic is 1:10-60; the mass fraction of the polyvinyl alcohol aqueous solution is 1-2%; and the amount of the polyvinyl alcohol aqueous solution added is 1-5% of the sum of the volume of the rice leaf folder sex pheromone liquid paraffin solution and the mixed gelatin solution.
8. The preparation method according to claim 5, characterized in that In steps (2) and (3), the stirring speed is 650-700 r / min and the time is 30-35 min; in step (4), the stirring speed is 400-450 r / min and the time is 30-35 min.
9. The preparation method according to claim 5, characterized in that In step (4), the amount of water added is 1 to 1.2 times the volume of the microcapsule agglomerates; the concentration of the glutaraldehyde aqueous solution is 1.5 to 2 mg / mL, and the amount added is 0.1 to 0.2 times the sum of the volumes of the microcapsule agglomerates and the water; and the drying is vacuum drying at 20 to 25° C. for 30 to 40 hours.
10. Use of the rice leaf folder sex pheromone microcapsule according to any one of claims 1 to 4 in controlling rice leaf folder.