A tea corner miridae trapping agent and a preparation method thereof

Abstract

The application discloses a tea corner miridae trapping agent and a preparation method thereof, and relates to the technical field of pest trapping agents in tea gardens. The trapping agent comprises beta-cyclodextrin, methyl salicylate and trans-2-hexenal, the beta-cyclodextrin at least forms an inclusion phase with the methyl salicylate, and the trapping agent further comprises an un-included loading phase outside the inclusion phase. The inclusion rate of the methyl salicylate is higher than the inclusion rate of the trans-2-hexenal, and the difference between the inclusion rates of the two is not less than 20 percentage points; the proportion of the trans-2-hexenal in the un-included loading phase is higher than the proportion of the methyl salicylate in the un-included loading phase, thereby forming an asymmetric phase distribution structure. The structure makes the two volatile components be released from the inclusion phase and the un-included loading phase together, and reduces the risk that the release proportion of the two components in a common mixed or common inclusion system drifts over time.

Description

Technical Field

[0001] This invention relates to the field of tea garden pest trapping agents, specifically a tea mirid bug trapping agent and its preparation method. Background Technology

[0002] The tea mirid bug is a common piercing-sucking pest in tea gardens. Existing studies on volatile matter trapping in tea gardens have focused on the effects of plant-derived volatile components such as methyl salicylate and trans-2-hexenal on the electrophysiological or behavioral responses of insects, and these volatile components can be loaded into lure carriers. These approaches typically focus on the screening, compounding, and behavioral responses of volatile components, primarily addressing the selection of odor sources for attraction. However, they often neglect the phase distribution, release sources, and changes in release ratios of various volatile components during lure placement.

[0003] Methyl salicylate and trans-2-hexenal are both plant-derived volatile components, but they differ in volatility, environmental stability, and binding ability to carriers or inclusion bodies. Using only ordinary physical mixing methods can easily lead to rapid loss of the more volatile component in the initial release phase, resulting in an imbalance in the proportion of complex volatile signals in the later stages. While using only ordinary co-inclusion methods can reduce volatilization loss to some extent, it is still difficult to directionally adjust the distribution ratio of the two volatile components in the inclusion phase, free phase, or adsorbed phase.

[0004] β-Cyclodextrins can form host-guest inclusion structures with some volatile small molecules and can be used to improve the release state of volatile components. However, conventional cyclodextrin inclusion typically focuses on improving the stability of a single volatile component or achieving overall sustained release, without addressing the structural design for the differences in the content distribution of methyl salicylate and trans-2-hexenal in the included and unincluded loaded phases. Related cyclodextrin inclusion technologies mostly aim at stabilizing, anti-oxidizing, or achieving overall sustained release of a single volatile component, typically focusing on increasing the proportion of that single component entering the cyclodextrin cavity or reducing its volatilization loss during storage and release. When two volatile components coexist, if the conventional co-inclusion approach of simultaneous addition is still used, the two components will compete for distribution within the cyclodextrin cavity, particle surface, and dry particle pores, and the initial feed ratio cannot be directly equated to the release ratio during the release cycle. Therefore, how to achieve a clearly directional differentiated distribution of the two volatile components in the encapsulated and unencapsulated loaded phases, thereby reducing the drift of the combined release ratio over time, remains a problem that cannot be directly solved by existing technologies.

[0005] Therefore, it is still necessary to provide a tea horn mirid bug trap that can form an asymmetric phase distribution structure and reduce the drift of the two-component release ratio, as well as a method for its preparation. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a tea horn mirid bug trap and its preparation method, thereby solving the problem of time-dependent release ratios of methyl salicylate and trans-2-hexenal in ordinary mixed or co-inclusion systems due to differences in volatility, environmental stability, and inclusion ability with β-cyclodextrin.

[0007] To achieve the above objectives, in a first aspect, this application provides a tea horn mirid bug trap, comprising β-cyclodextrin, methyl salicylate, and trans-2-hexenal; wherein the β-cyclodextrin forms an inclusion phase with at least the methyl salicylate; the trap further comprises an unincluded loaded phase located outside the inclusion phase, the unincluded loaded phase being a free phase and / or an adsorbed phase; wherein the inclusion rate of methyl salicylate is higher than that of trans-2-hexenal, and the difference in inclusion rates between methyl salicylate and trans-2-hexenal is not less than 20 percentage points; the proportion of trans-2-hexenal in the unincluded loaded phase is higher than that of methyl salicylate in the unincluded loaded phase, thereby forming an asymmetric phase distribution structure in the trap, and causing the methyl salicylate and trans-2-hexenal to be released jointly by the inclusion phase and the unincluded loaded phase.

[0008] Preferably, the mass ratio of methyl salicylate to trans-2-hexenal is 1:(0.9 to 1.1).

[0009] Preferably, the molar ratio of the total amount of β-cyclodextrin to the total amount of methyl salicylate and trans-2-hexenal is (0.5-0.8):1.

[0010] Preferably, the inclusion rate of the methyl salicylate is 70% to 80%, the inclusion rate of the trans-2-hexenal is 35% to 40%, and the proportion of the trans-2-hexenal in the unincluded supported phase is 60% to 65%.

[0011] Preferably, the free phase or adsorbed phase retains at least one of methyl salicylate and trans-2-hexenal, and the proportion of trans-2-hexenal in the free phase or adsorbed phase is higher than the proportion of methyl salicylate in the free phase or adsorbed phase, so that the trap forms a biphase loading structure in which the inclusion phase and the free phase or adsorbed phase coexist; at aging test time points of 7 days, 14 days and 30 days, both methyl salicylate and trans-2-hexenal can be detected; when the release ratio is the ratio of the release rate of methyl salicylate to the release rate of trans-2-hexenal at the same time point, the difference between the maximum and minimum values ​​of the release ratio at the above aging test time points is not greater than 0.6.

[0012] Preferably, the unencapsulated loaded phase retains methyl salicylate and / or trans-2-hexenal that have not entered the β-cyclodextrin cavity, and the unencapsulated loaded phase is formed from the surface of the β-cyclodextrin particles and / or the pores of the dried particles.

[0013] To achieve the above objective, in a second aspect, this application provides a method for preparing a tea mirid bug trap, comprising:

[0014] β-Cyclodextrin was dispersed in a solvent system to obtain a β-cyclodextrin system;

[0015] Methyl salicylate was added to the β-cyclodextrin system and pre-encapsulated to obtain a first mixed system containing a β-cyclodextrin inclusion phase;

[0016] Add trans-2-hexenal to the first mixing system and perform secondary mixing. The temperature of the secondary mixing is lower than the temperature of the pre-encapsulation treatment, so that trans-2-hexenal is retained more in the unencapsulated loaded phase outside the encapsulated phase than methyl salicylate.

[0017] The system after secondary mixing was dried at low temperature to obtain a tea horn mirid bug trap with an asymmetric phase distribution structure.

[0018] Preferably, the solvent system is an aqueous solution of ethanol with a volume fraction of 30%.

[0019] Preferably, the pre-packaging treatment is carried out at 25°C for 2.0 h; the secondary mixing is carried out at 15°C for 0.5 h; and the low-temperature drying includes pre-freezing at -40°C for 4 h and freeze-drying for 24 h.

[0020] Preferably, the inclusion rate and the unincluded loading ratio are determined by the following method: a non-included loading phase correlation detection solution is obtained by short-time n-hexane elution, and an inclusion-coated phase correlation detection solution is obtained by ultrasonic extraction with ethanol aqueous solution; the contents of methyl salicylate and trans-2-hexenal in the two detection solutions are determined respectively to calculate the inclusion rate and the unincluded loading ratio of methyl salicylate and trans-2-hexenal.

[0021] The improvement in this application does not focus on re-screening the behavioral response activities of methyl salicylate or trans-2-hexenal, nor on simply increasing the total inclusion rate of the two volatile components. Instead, it transforms the problem of the drift in the combined release ratio of the two components into a problem of phase distribution regulation between the included and unincluded loaded phases. Specifically, this application uses methyl salicylate pre-inclusion, low-temperature secondary addition of trans-2-hexenal, and low-temperature drying to ensure that methyl salicylate is more distributed in the included phase than trans-2-hexenal, and that trans-2-hexenal is more retained in the unincluded loaded phase than methyl salicylate. This results in an asymmetric phase distribution structure that can be quantitatively identified by phase fractionation extraction and GC-MS.

[0022] This invention provides a tea horn mirid bug trap and its preparation method, which has the following beneficial effects:

[0023] (1) Compared with ordinary physical mixing traps, this invention forms an inclusion phase through β-cyclodextrin and retains a free or adsorbed phase, allowing methyl salicylate and trans-2-hexenal to exist in different proportions in the inclusion phase and the free or adsorbed phase, thereby forming an asymmetric phase distribution structure. This structure is beneficial for the two volatile components to be released jointly by different phases within a predetermined release period, reducing the risk of excessively rapid initial release or insufficient release in the later stage caused by single-phase loading. Compared with ordinary co-inclusion systems, this invention does not release all two volatile components in the same inclusion manner, but retains a free or adsorbed phase outside the inclusion phase, so that the two components have different release sources, which is beneficial for maintaining the complex odor release relationship between methyl salicylate and trans-2-hexenal.

[0024] (2) The preparation method of the present invention uses methyl salicylate pre-encapsulation, trans-2-hexenal secondary addition and low temperature drying treatment to make methyl salicylate more distributed in the encapsulated phase than trans-2-hexenal, and trans-2-hexenal more retained in the unencapsulated loaded phase than methyl salicylate. This reduces the drift of the release ratio of the two volatile components during the release cycle through the asymmetric phase distribution structure, rather than re-screening the active substances that respond to the behavior of tea horn mirid bugs.

[0025] (3) This invention employs a sequence of first adding methyl salicylate for pre-encapsulation, followed by adding trans-2-hexenal for secondary mixing. This allows methyl salicylate to preferentially occupy the β-cyclodextrin cavity and form an inclusion phase dominated by methyl salicylate. Subsequently, trans-2-hexenal is added at a lower temperature, which reduces the displacement disturbance of the already formed inclusion phase by trans-2-hexenal, while also allowing it to remain more in the unencapsulated loaded phase outside the inclusion phase compared to methyl salicylate. Subsequent freeze-drying reduces the free volatilization and redistribution of the two volatile components during the drying process, thus solidifying the phase distribution state formed by the pre-encapsulation and secondary addition. Therefore, this method is neither a conventional co-encapsulation process nor a simple physical mixing process, but rather a method that controls the distribution difference of the two volatile components in the inclusion phase and the unencapsulated loaded phase through the combined control of the feeding sequence and low-temperature drying. Detailed Implementation

[0026] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In this embodiment of the invention, the inclusion phase refers to the structural portion of β-cyclodextrin that forms a host-guest inclusion relationship with methyl salicylate and / or trans-2-hexenal. The uninclusion-loaded phase refers to the structural portion of methyl salicylate and / or trans-2-hexenal located outside the inclusion phase and retaining the structural portion that has not entered the β-cyclodextrin cavity; this uninclusion-loaded phase can be a free phase and / or an adsorbed phase. The free phase refers to the methyl salicylate and / or trans-2-hexenal portion that has not entered the β-cyclodextrin cavity but remains in the trapping agent system.

[0028] The adsorbed phase refers to the methyl salicylate and / or trans-2-hexenal fractions that do not enter the β-cyclodextrin cavity but are retained on the surface of the β-cyclodextrin particles and / or in the pores of the dried particles. The asymmetric phase distribution structure refers to the different content distribution ratios of methyl salicylate and trans-2-hexenal in the included and unincluded loaded phases, with methyl salicylate being more distributed in the included phase than trans-2-hexenal, and trans-2-hexenal being more distributed in the unincluded loaded phase than methyl salicylate.

[0029] The release ratio refers to the ratio between the release amount of methyl salicylate and the release amount of trans-2-hexenal at the same time point or within the same time period. The release ratio drift refers to the deviation of the release ratio or release rate ratio of methyl salicylate to trans-2-hexenal relative to the initial release ratio or target release ratio within a predetermined release period. In the experimental examples of this application, the difference between the maximum and minimum release ratio values ​​characterizes the magnitude of the release ratio variation.

[0030] Example: Preparation of asymmetric phase-distributed tea horn mirid bug trap: 500.00 mg of β-cyclodextrin was weighed and added to 20.0 mL of 30% (v / v) ethanol aqueous solution. The mixture was stirred at 25°C in the dark for 30 min to fully disperse the β-cyclodextrin and obtain the β-cyclodextrin system.

[0031] 50.00 mg of methyl salicylate was added to the β-cyclodextrin system, and the mixture was stirred in a sealed, light-protected environment at 25°C for 2.0 h to allow the methyl salicylate to pre-encapsulate the β-cyclodextrin, thus obtaining a first mixed system containing the β-cyclodextrin inclusion phase.

[0032] Add 50.00 mg of trans-2-hexenal to the first mixing system and mix in a sealed, light-protected environment at 15°C for 0.5 h, so that part of the trans-2-hexenal enters the inclusion phase and the other part remains in the uninclusion loaded phase outside the inclusion phase.

[0033] The mixture was pre-frozen at -40℃ for 4 h, followed by freeze-drying for 24 h to obtain tea horn bug trap sample E1. This sample contained 500.00 mg of β-cyclodextrin, 50.00 mg of methyl salicylate, and 50.00 mg of trans-2-hexenal; the molar ratio of β-cyclodextrin to the total amount of the two volatile components was approximately 0.53:1.

[0034] Comparative Examples 1 to 3, with Comparative Example 1 being a standard physical mixture sample C1. 50.00 mg of methyl salicylate and 50.00 mg of trans-2-hexenal were weighed and directly mixed with 500.00 mg of dried glass beads, without the addition of β-cyclodextrin or any inclusion treatment. Glass beads were used as an inert support in this comparative example to eliminate the interference of the support adsorption effect on the release test results, ensuring that the release state of methyl salicylate and trans-2-hexenal in sample C1 is close to the free volatility baseline, thus providing a control against the asymmetric phase partition structure of E1.

[0035] Comparative Example 2 is the common co-inclusion sample C2. 500.00 mg of β-cyclodextrin was weighed and added to 20.0 mL of 30% (v / v) ethanol aqueous solution, and stirred at 25°C for 30 min. Simultaneously, 50.00 mg of methyl salicylate and 50.00 mg of trans-2-hexenal were added, and the mixture was stirred in a sealed, light-protected environment at 25°C for 2.0 h, followed by drying according to the freeze-drying conditions of the examples. Because methyl salicylate and trans-2-hexenal were added to the β-CD system simultaneously, they competed for the β-CD cavity. Since methyl salicylate pre-occupation was not performed, a directional asymmetric phase distribution structure could not be formed, where methyl salicylate preferentially distributes in the inclusion phase and trans-2-hexenal is more abundantly distributed in the uninclusion-supported phase.

[0036] Comparative Example 3 was sample D3, prepared by reverse addition. 500.00 mg of β-cyclodextrin was weighed and added to 20.0 mL of a 30% (v / v) ethanol aqueous solution, and stirred at 25°C for 30 min. First, 50.00 mg of trans-2-hexenal was added and stirred in a sealed, light-protected environment at 25°C for 2.0 h. Then, 50.00 mg of methyl salicylate was added and mixed in a sealed, light-protected environment at 15°C for 0.5 h. Subsequently, the mixture was dried according to the freeze-drying conditions described in the example. Comparative Example 3 did not meet the requirement that the inclusion rate of methyl salicylate was higher than that of trans-2-hexenal, with a difference of not less than 20 percentage points; therefore, it was not used as a sample in this invention.

[0037] Experimental Example 1: Verification of the phase distribution structure and release relationship of the tea horn mirid bug trap;

[0038] This experimental example was used to verify the presence of β-cyclodextrin-included and unincluded loaded phases in the tea horn bug trap of this application, and to verify the differences in the content distribution of methyl salicylate and trans-2-hexenal in different phases. Methyl salicylate is abbreviated as MeSA, trans-2-hexenal as HEX, and β-cyclodextrin as β-CD.

[0039] A short-term hexane elution of 30 s was performed, followed by shaking. The eluent was collected as the non-inclusion-loaded phase correlation assay solution. The eluted solid was added to a 50% ethanol aqueous solution and ultrasonically extracted at 50 °C for 30 min to release the β-CD inclusion guests. The extract was collected as the inclusion phase correlation assay solution. Both assay solutions were quantified using GC-MS, with n-dodecane as an internal standard. The total content in this experiment was calculated as the sum of the inclusion phase correlation content and the non-inclusion-loaded phase correlation content.

[0040] Before GC-MS quantification, a series of standard solutions were prepared using MeSA and HEX standards, and an internal standard curve was established using n-dodecane as an internal standard. After verifying the recovery rate of the sample pretreatment process using spiked blank matrix samples, the contents of MeSA and HEX in each detection solution were quantitatively analyzed, as shown in Table 1.

[0041] Table 1 Sample Setup Table

[0042] Sample number Sample type MeSA dosage (mg) HEX feed dosage (mg) β-CD dosage (mg) Preparation method description C1 Ordinary physical mixing 50.00 50.00 — MeSA is directly mixed with HEX and an inert carrier without β-CD inclusion processing. C2 Common common knot 50.00 50.00 500 MeSA and HEX were simultaneously added to the β-CD system, co-encapsulated, and then dried at low temperature. E1 First, pre-wrap with MeSA, then add HEX. 50.00 50.00 500 First add MeSA pre-encapsulation, then add HEX, and dry at low temperature. D3 First, pre-package using HEX, then add MeSA. 50.00 50.00 500 First add HEX pre-coating, then add MeSA, and dry at low temperature.

[0043] 2. Phase partitioning detection: A short-time hexane elution for 30 s was performed, followed by shaking. The eluent was collected as the free phase or adsorbed phase correlation detection solution. The eluted solid was then ultrasonically extracted in 50% ethanol aqueous solution at 50℃ for 30 min to release the β-CD inclusion guests. The extract was collected as the inclusion phase correlation detection solution. Both the eluent and extract were quantified by GC-MS, with n-dodecane as an internal standard. The total content in this experiment was calculated by adding the content correlated with the inclusion phase to the content correlated with the free or adsorbed phase, as shown in Table 2.

[0044] Table 2 Detection results of phase distribution between E1 and D3

[0045] sample Components Total content (mg) Inclusion phase related content (mg) Content (mg) in free phase or adsorbed phase Encapsulation rate (%) Free phase or adsorbed phase ratio (%) E1 Methyl salicylate (MeSA) 45.13 33.53 11.60 74.3 25.7 E1 trans-2-hexenal (HEX) 43.29 16.15 27.14 37.3 62.7 D3 Methyl salicylate (MeSA) 44.84 24.08 20.76 53.7 46.3 D3 trans-2-hexenal (HEX) 43.12 25.92 17.20 60.1 39.9

[0046] As shown in the table above, the inclusion rate of MeSA in E1 is 74.3%, while that of HEX is 37.3%, with a difference of 37.0 percentage points. Simultaneously, the proportion of MeSA in the free or adsorbed phase is 25.7%, while that of HEX is 62.7%. These results indicate that MeSA in E1 is mainly distributed in the inclusion phase, while HEX is more abundant in the free or adsorbed phase, and their content distribution ratios differ in different phases.

[0047] In D3, the inclusion rate of MeSA was 53.7%, and that of HEX was 60.1%, with a difference of 6.4 percentage points between the two components; its asymmetric phase partitioning was lower than that of E1. Therefore, E1 was selected as the sample for subsequent release testing and denoted as E1, as shown in Table 3.

[0048] Table 3 Comparison of phase allocation differences between E1 and D3 and selection of E1

[0049] sample MeSA binding rate (%) HEX binding rate (%) Difference in inclusion rates between the two components (percentage points) Selection Conclusion E1 74.3 37.3 37.0 Selected as E1 D3 53.7 60.1 6.4 Do not select

[0050] In this experimental example, detection means that under dynamic headspace adsorption-thermal desorption gas chromatography detection conditions, after reaching the corresponding test time point under aging conditions of 25℃ and 60% relative humidity, an equal amount of sample is placed in a sealed bottle, and the sample is purged with a purge flow of 0.1 L / min for 30 min. After collection through an adsorption tube and thermal desorption injection, the identifiable chromatographic peaks of the corresponding components can be obtained.

[0051] 3. Release Relationship Test: Release tests were conducted using samples C1, C2, and the selected E1. Dynamic headspace adsorption-thermal desorption gas chromatography was employed for the release analysis. At each time point, the collected samples were placed in sealed vials and purged with a purge stream of 0.1 L / min for 30 min. The adsorption tubes were collected, and the samples were thermally desorbed and analyzed by gas chromatography. The results were expressed as the detected instantaneous release rate, in ng / h. Each time point was repeated three times, and the average value was recorded (see Table 4).

[0052] Table 4. Release test results of C1, C2, and E1

[0053] sample time MeSA release rate (ng / h) HEX release rate (ng / h) Release ratio (MeSA / HEX) Whether both components were detected Remark C1 0 days 880.54 1100.78 0.80 yes C1 7 days 467.17 311.46 1.50 yes C1 14 days 197.89 68.81 2.88 yes C1 30 days 81.49 8.43 9.67 yes HEX is close to the detection limit C2 0 days 290.65 626.84 0.46 yes C2 7 days 209.10 307.30 0.68 yes HEX release rate decreases C2 14 days 157.09 186.67 0.84 yes C2 30 days 98.94 65.86 1.50 yes E1 0 days 268.91 676.10 0.40 yes E1 7 days 241.25 354.65 0.68 yes E1 14 days 244.05 276.26 0.88 yes The ratio tends to stabilize E1 30 days 209.43 211.68 0.99 yes Two components were continuously detected

[0054] In the C1 ordinary physical mixture sample, HEX release decayed rapidly in the free volatile state, with the release ratio changing from 0.80 at day 0 to 9.67 at day 30, a change of 8.87; at day 30, the HEX release rate was 8.43 ng / h, close to the method detection limit.

[0055] In the C2 common co-encapsulation sample, β-CD inclusion overall slowed the release of both components, with the release ratio changing from 0.46 at day 0 to 1.50 at day 30, a change of 1.04. This result indicates that common co-encapsulation can reduce the ratio change caused by free volatilization, but the release relationship between the two components still changes over time; that is, the release ratio of Comparative Example 2 (C2) changed by 1.04 from day 0 to day 30.

[0056] In the E1 asymmetric phase-partitioned sample, MeSA was predominantly in the inclusion phase, while HEX was largely retained in the free or adsorbed phase. The release rate of MeSA in E1 varied from 268.91 ng / h to 209.43 ng / h between days 0 and 30, with a retention rate of approximately 77.9%; the release rate of HEX varied from 676.10 ng / h to 211.68 ng / h. The release ratio in E1 varied from 0.40 at day 0 to 0.99 at day 30, a variation of 0.59, lower than that of C1 (8.87) and C2 (1.04). Furthermore, MeSA and HEX were detectable in E1 at days 7, 14, and 30.

[0057] The above results indicate that the E1 sample formed by pre-encapsulating MeSA and then adding HEX can form an asymmetric phase distribution structure in which the encapsulated phase and the free or adsorbed phase coexist. During the predetermined release period of 7 to 30 days, both MeSA and HEX can be continuously detected in the E1 sample, and the change in the release ratio of the two components is lower than that of ordinary physical mixed samples and ordinary co-encapsulated samples.

[0058] Although Comparative Example 2 also uses β-CD and can slow down the free volatilization of the two volatile components, it adopts a common co-inclusion method of simultaneous addition of methyl salicylate and trans-2-hexenal. This fails to form a directional phase distribution structure in E1 where methyl salicylate is mainly distributed in the inclusion phase and trans-2-hexenal is more distributed in the unincluded loaded phase. Its release ratio variation from day 0 to 30 remains 1.04. In Comparative Example 3, after adopting a reverse feeding sequence, the inclusion rate of trans-2-hexenal is higher than that of methyl salicylate, and the difference in inclusion rates between the two components is only 6.4 percentage points, which does not meet the requirement of not less than 20 percentage points as specified in this application. Therefore, the technical effect of this application is not solely due to the ordinary sustained-release effect of β-CD, but rather to the asymmetric phase distribution structure formed by the pre-inclusion of methyl salicylate, the secondary low-temperature addition of trans-2-hexenal, and low-temperature drying.

[0059] The asymmetric phase distribution structure of this embodiment can be identified by phase fractionation extraction and GC-MS quantification. For the sample to be tested, the unincluded loaded phase-related components are first obtained by short-time n-hexane elution, and then the included phase-related components are released by ultrasonic extraction with ethanol-water solution. After measuring the contents of MeSA and HEX, it can be determined whether MeSA is more distributed in the included phase than HEX, and whether HEX is more distributed in the unincluded loaded phase than MeSA. This characterization method can distinguish the product structure of this application from ordinary physically mixed samples, ordinary co-included samples, and reverse-feed samples.

[0060] Furthermore, the attractant sample prepared by this invention can be used in conventional lure shells, breathable bags, slow-release boxes, or other tea garden pest trapping devices. This loading method does not change the asymmetric phase distribution structure of the coexistence of the bound and unbound loaded phases of this invention, nor is it a necessary technical feature for achieving a stable release ratio in this invention.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A tea-horned mirid bug trap, characterized in that, The trap comprises β-cyclodextrin, methyl salicylate, and trans-2-hexenal; the β-cyclodextrin forms an inclusion phase with at least the methyl salicylate; the trap further comprises an unincluded loaded phase outside the inclusion phase, the unincluded loaded phase being a free phase and / or an adsorbed phase; wherein the inclusion rate of methyl salicylate is higher than that of trans-2-hexenal, and the difference in inclusion rates between methyl salicylate and trans-2-hexenal is not less than 20 percentage points; the proportion of trans-2-hexenal in the unincluded loaded phase is higher than that of methyl salicylate in the unincluded loaded phase, thereby forming an asymmetric phase distribution structure in the trap and causing the methyl salicylate and trans-2-hexenal to be released jointly by the inclusion phase and the unincluded loaded phase.

2. The tea-horned mirid bug trap according to claim 1, characterized in that, The mass ratio of methyl salicylate to trans-2-hexenal is 1:(0.9-1.1).

3. The tea-horned mirid bug trap according to claim 1, characterized in that, The molar ratio of the total amount of β-cyclodextrin to the total amount of methyl salicylate and trans-2-hexenal is (0.5-0.8):

1.

4. The tea-horned mirid bug trap according to claim 1, characterized in that, The inclusion rate of the methyl salicylate is 72% to 76%, the inclusion rate of the trans-2-hexenal is 36% to 39%, and the proportion of the trans-2-hexenal in the unincluded supported phase is 61% to 64%.

5. The tea-horned mirid bug trap according to claim 4, characterized in that, The free phase or adsorbed phase retains at least one of methyl salicylate and trans-2-hexenal, and the proportion of trans-2-hexenal in the free phase or adsorbed phase is higher than the proportion of methyl salicylate in the free phase or adsorbed phase, so that the trapping agent forms a biphase loading structure in which the inclusion phase and the free phase or adsorbed phase coexist; at aging test time points of 7 days, 14 days and 30 days, both methyl salicylate and trans-2-hexenal can be detected. When the release ratio is taken as the ratio of the release rate of methyl salicylate to the release rate of trans-2-hexenal at the same time point, the difference between the maximum and minimum values ​​of the release ratio at the above-mentioned aging test time points is no greater than 0.

6.

6. The tea-horned mirid bug trap according to claim 5, characterized in that, The unbound loaded phase retains methyl salicylate and / or trans-2-hexenal that have not entered the β-cyclodextrin cavity, and the unbound loaded phase is formed from the surface of the β-cyclodextrin particles and / or the pores of the dried particles.

7. The tea-horned mirid bug trap according to any one of claims 1 to 6, characterized in that, The inclusion rate and the proportion of unincluded loaded phases were determined by the following method: the unincluded loaded phase correlation detection solution was obtained by short-time n-hexane elution, and the inclusion phase correlation detection solution was obtained by ultrasonic extraction with ethanol aqueous solution. The contents of methyl salicylate and trans-2-hexenal in the two test solutions were determined separately to calculate the inclusion rate and unincluded loading ratio of methyl salicylate and trans-2-hexenal.

8. A method for preparing the tea horn mirid bug trap according to any one of claims 1 to 6, characterized in that, include: β-Cyclodextrin was dispersed in a solvent system to obtain a β-cyclodextrin system; Methyl salicylate was added to the β-cyclodextrin system and pre-encapsulated to obtain a first mixed system containing a β-cyclodextrin inclusion phase; Add trans-2-hexenal to the first mixing system and perform secondary mixing. The temperature of the secondary mixing is lower than the temperature of the pre-encapsulation treatment, so that trans-2-hexenal is retained more in the unencapsulated loaded phase outside the encapsulated phase than methyl salicylate. The system after secondary mixing was dried at low temperature to obtain a tea horn mirid bug trap with an asymmetric phase distribution structure.

9. The method according to claim 8, characterized in that, The solvent system is a 30% (v / v) aqueous solution of ethanol.

10. The method according to claim 8, characterized in that, The pre-packaging treatment is carried out at 25°C for 2.0 h; the secondary mixing is carried out at 15°C for 0.5 h; the low-temperature drying includes pre-freezing at -40°C for 4 h and freeze-drying for 24 h.