A red turpentine beetle repellent and its preparation method and application

Abstract

The present application relates to the technical field of green control of Dendroctonus valens, and particularly relates to a Dendroctonus valens repellent, a preparation method and application thereof. The repellent component comprises opoponax oil. It is found by the present application that opoponax oil has obvious repellent effect on Dendroctonus valens, and opoponax oil can be used as a Dendroctonus valens repellent, and the Dendroctonus valens can be repelled in production to protect the pine forest ecosystem. The repellent has good repellent effect, is stable, is environment-friendly, and has broad industrialization prospects.

Description

Technical Field

[0001] This invention relates to the field of green control technology for red turpentine beetle, and in particular to a red turpentine beetle repellent, its preparation method, and its application. Background Technology

[0002] Red turpentine beetle ( Dendroctonus valens Leconte (also known as the red turpentine beetle) belongs to the family Scolytinae in the order Coleoptera. It is a forest borer native to North America. In its habitat in my country, the red turpentine beetle typically has 1-2 generations per year, overwintering as larvae or adults in the phloem of the trunk or roots. In recent years, the red turpentine beetle has spread to Inner Mongolia, Liaoning, and other regions of my country, and its host plant range has also expanded. Previously primarily damaging Pinus tabuliformis, it now also damages Larix gmelinii and Pinus sylvestris.

[0003] Adult red turpentine bark beetles primarily rely on sight and smell to locate hosts. They exhibit strong positive attraction to volatile substances emitted by pine trees (such as α-pinene), particularly favoring physiologically weakened trees. They are also attracted to aggregation pheromones released by their own kind, leading to invasive aggregations. In recent years, significant progress has been made in green control technologies for red turpentine bark beetles. Currently, a baiting and killing technique based on attractants has been developed, with the core attractants being pine volatile components, including α-pinene, β-pinene, and 3-carene. Internationally, the control of bark beetles is mainly based on a "push-pull" strategy, i.e., the combined use of attractants and repellents. To date, there are few reports on the composition of repellents for red turpentine bark beetles; the confirmed repellent activity comes from a five-component composition consisting of nonanal, 3-octanol, trans-2-hexenal, salicylaldehyde, and verbenaenolide. It can be seen that the composition of this component is quite complex, and the preparation requires precise control over the proportions. Therefore, it is currently necessary to screen for repellents against red liptinid beetles that have simple component structures and stable effects.

[0004] In summary, the repellents and application technologies for the red turpentine beetle are still immature, and simply relying on attractants cannot completely prevent the beetle from infesting pine trees. Therefore, there is an urgent need to develop repellents for the red turpentine beetle and their application technologies, to create repellents or interfere with the beetle's aggregation and host plant attack behaviors, and to achieve combined use with attractants, thus improving the integrated control technology system for the red turpentine beetle. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a repellent for the red turpentine beetle, its preparation method, and its application, used to repel or disrupt the aggregation of red turpentine beetle populations in forests. The repellent can be fixed to the trunk of pine trees, effectively preventing the aggregation and damage caused by the red turpentine beetle and protecting the host pine tree from harm.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides the application of repellent components in controlling the damage caused by the red turpentine beetle in forests, wherein the repellent components include turpentine.

[0008] Preferably, the mass of the fentanyl is 4g.

[0009] The present invention also provides a repellent for red liptin beetle, comprising a repellent component, sterile absorbent cotton, and a polyethylene plastic bag;

[0010] The repellent ingredient includes fentanyl.

[0011] Preferably, each sterile absorbent cotton ball contains 4g of fentanyl.

[0012] Preferably, the polyethylene plastic bag is made of low-density polyethylene with a mass percentage of 99%, a thickness of 12 mils, a length of 100 mm, and a width of 50 mm.

[0013] The present invention also provides a method for preparing the repellent for the red liptin beetle described in the above technical solution, comprising the following steps: dripping the repellent component onto a sterile absorbent cotton carrier, then placing it in a polyethylene plastic bag and sealing it.

[0014] The present invention also provides an application of the red turpentine beetle repellent described in the above-mentioned technical solution in controlling the damage caused by the red turpentine beetle in forests.

[0015] Preferably, the red grease beetle repellent is suspended in the forest at a height of 1m and a spacing of 100m.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) Used to repel red turpentine beetle, prevent red turpentine beetle from accumulating and causing damage on the host, and reduce the damage rate of the host pine tree: Since the red turpentine beetle repellent attractant of the present invention has high repellent biological activity, when used in healthy forests, it repels low-density red turpentine beetles inside the forest and prevents them from accumulating and causing damage on the trees.

[0018] (2) Used to inhibit the behavior of the red turpentine beetle in attacking its host. The repellent of the present invention has highly efficient repellent activity and has a significant antagonistic effect on attractants with host localization function. Its use in forests can reduce the attack and infection of pine trees by the red turpentine beetle.

[0019] (3) It can be used in combination with attractants to form a "push-pull" control, which can meet the protection needs of key forest areas in production.

[0020] The repellent for the red turpentine beetle provided by this invention uses sterile degreased cotton and 12-filament black polyethylene plastic bags as carriers, making it easy to process and produce at a low cost. The repellent components can be stably released on the slow-release carrier. This repellent is a highly effective repellent for the red turpentine beetle, and this invention is an environmentally friendly green biotechnology that can be used to repel the aggregation and invasion of the red turpentine beetle, thereby protecting pine forests. The repellent has been tested in the Saihanba Mechanical Forest Farm in Hebei Province, verifying its good repellent activity and stability. This red turpentine beetle repellent has broad prospects for industrialization. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0022] Figure 1 The results of a comparative study on the repellency behavior of various repellents against the red turpentine beetle, conducted in June 2024.

[0023] Figure 2 The study aimed to investigate the inhibitory effects of different doses of fentanyl on the red turpentine beetle in June 2024.

[0024] Figure 3 The effect of fentanyl on the invasion behavior of red turpentine beetle in July 2025. Detailed Implementation

[0025] This invention provides the application of a repellent component in controlling damage caused by the red turpentine beetle in forests, wherein the repellent component includes senna. The source and purity (mass %) of the above repellent component are as follows: senna (CAS: 7787-20-4, Macklin, 98%).

[0026] This invention provides a repellent for the red liptin beetle, comprising a repellent component, sterile absorbent cotton, and a polyethylene plastic bag; the repellent component comprises fentanyl. In this invention, each sterile absorbent cotton preferably contains 4g of fentanyl. In this invention, the polyethylene plastic bag is preferably made of low-density polyethylene with a mass percentage of 99%, a thickness of 12 mils, a length of 100mm, and a width of 50mm.

[0027] The present invention also provides a method for preparing the repellent for the red liptin beetle described in the above technical solution, comprising the following steps: dripping the repellent component onto a sterile absorbent cotton carrier, then placing it in a polyethylene plastic bag and sealing it.

[0028] This invention also provides the application of the red turpentine beetle repellent described in the above-mentioned technical solution in controlling the damage caused by the red turpentine beetle in forests. Preferably, the red turpentine beetle repellent is suspended in the forest at a height of 1m and a spacing of 50m.

[0029] The attractants for the red liptinous bark beetle prepared in the following examples all used commercially available α-pinene, β-pinene, and 3-carene, with chemical purity and isomer purity both greater than 97%; the repellent used was commercially available fentanyl, with a chemical purity of 98%; other commercially available agents were used: 1-octen-3-ol, cis-3-hexenol, and trans-2-hexenol, with chemical purity and isomer purity both greater than 95%.

[0030] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0031] Example 1

[0032] Comparative results of experiments on the repellency behavior of various repellents against the red turpentine beetle.

[0033] The attractants for the red liptinous bark beetle prepared in this embodiment all used commercially available α-pinene, β-pinene, and 3-carene, with chemical purity and isomer purity both greater than 97%; commercially available fentanyl was used, with a purity of 98%; and 1-octen-3-ol and trans-2-hexenol were used, with chemical purity and isomer purity both greater than 95%.

[0034] The following five treatments are prepared according to the testing requirements.

[0035] Process 1: Blank handling;

[0036] Treatment 2: 1g of α-pinene, 1g of β-pinene, and 3g of 3-carene;

[0037] Treatment 3: 1g of α-pinene, 1g of β-pinene, 3g of 3-carene, and 2g of sennae;

[0038] Treatment 4: 1g of α-pinene, 1g of β-pinene and 3g of 3-carene, and 2g of 1-octen-3-ol;

[0039] Treatment 5: 1g of α-pinene, 1g of β-pinene, 3g of 3-carene, and 2g of trans-2-hexenol;

[0040] (1) α-pinene, β-pinene and 3-carene were prepared according to the above-mentioned dosage to obtain an attractant for the red liptinous beetle. Fenone, 1-octen-3-ol and trans-2-hexenol were added dropwise onto a sterile absorbent cotton carrier according to the above-mentioned dosage to prepare a sustained-release repellent.

[0041] (2) Preparation and storage of lure and repellent: The lure was added to a 12-filament black polyethylene plastic bag containing degreased cotton and sealed with a sealing machine to obtain the lure. The repellent component was dripped onto a sterile degreased cotton carrier, placed in a 12-filament black polyethylene plastic bag, and sealed with a sealing machine to obtain a repellent slow-release bag; the polyethylene plastic bag was made of low-density polyethylene with a mass percentage of 99%, a thickness of 12 filaments, a length of 100 mm, and a width of 50 mm. The prepared lure and repellent slow-release bag were sealed in aluminum foil and refrigerated at 4°C.

[0042] (3) Field application of repellents:

[0043] a) Experiment location: Saihanba Mechanical Forest Farm, Hebei Province.

[0044] b) Construction of the trap: The trap mainly consists of a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. The large and small plates are crossed to form a cross shape (500mm high, 300mm wide), connected to the top cover via a hook at the top, and connected to the funnel via a hook at the bottom. The flared opening for connecting the insect collection bottle is fitted over the lower part of the funnel and connected to the collection bottle.

[0045] c) Hanging position of lure and repellent: Hang the drug combination in the middle position 20cm from the top of the funnel-shaped bark beetle trap. The drug combination consists of one attractant and one repellent for the red turpentine bark beetle (open the aluminum foil before use to get the repellent slow-release bag).

[0046] d) Field setup of the traps: Three replicates were set up for each experimental treatment. The traps were set up at the edge of the North China larch forest, with a spacing of about 100m between the traps. Two 3m long and 0.5cm thick wires were connected between the two trees, and the traps were then fixed in the middle of the wires. The insect collection bottle of the trap was 1m off the ground.

[0047] e) Data collection and trap emptying: Each treatment in this experiment was replicated three times, and the number of bark beetles captured in each treatment was the average of the three traps. Depending on the weather conditions, the number of bark beetles in the collection bottles was observed every 7 days. After counting, the collected bark beetles were placed in a plastic box and taken to the laboratory.

[0048] The application of the above-described specific usage steps for repelling the red turpentine beetle was carried out. From June 1st to June 15th, 2024, traps with blank lures (treatment 1) served as a blank control, while traps with plant-derived red turpentine beetle attractants (treatment 2) served as a positive control. Specific results are shown in Table 1 and [Table data would be inserted here]. Figure 1 The traps were spaced 100m apart, and the collection bottles were approximately 1m off the ground. Each treatment was replicated three times, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the collection bottles was observed every 5 days, depending on weather conditions.

[0049] Table 1. Comparative results of tests on the repellency behavior of various repellents against the red turpentine beetle.

[0050]

[0051] From Table 1 and Figure 1 The results show that, based on the insect-attracting effect analysis, the blank treatment (treatment 1) had no attractant activity against *Lysimachia rubrum*, while the plant-derived attractant for *Lysimachia rubrum* (treatment 2) had a good attractant effect. The attractants for *Lysimachia rubrum* (treatments 3, 4, and 5) reduced the number of *Lysimachia rubrum* attracted compared to treatment 2, but treatment 3 had the greatest impact on the number of *Lysimachia rubrum* captured. Treatments 4 and 5 also reduced the attractant effect of the plant-derived attractant on *Lysimachia rubrum*. This experiment demonstrates that when the plant-derived attractant for *Lysimachia rubrum* is used in combination with fentanyl, 1-octen-3-ol, and trans-2-hexenol, the number of *Lysimachia rubrum* captured can be reduced, indicating that fentanyl, 1-octen-3-ol, and trans-2-hexenol are antagonists of the *Lysimachia rubrum* attractant, but fentanyl has the strongest inhibitory effect on the attractant.

[0052] Example 2

[0053] Experiment on the inhibitory effect of different doses of fentanyl on red liptin beetle

[0054] The following five treatments are prepared according to the testing requirements:

[0055] Process 1: Blank handling;

[0056] Treatment 2: 1g of α-pinene, 1g of β-pinene, and 3g of 3-carene;

[0057] Treatment 3: 1g of α-pinene, 1g of β-pinene and 3g of 3-carene, and 1g of sennae;

[0058] Treatment 4: 1g of α-pinene, 1g of β-pinene, 3g of 3-carene, and 2g of sennae;

[0059] Treatment 5: 1g of α-pinene, 1g of β-pinene, 3g of 3-carene, and 4g of fentanyl;

[0060] Treatment 6: 1g of α-pinene, 1g of β-pinene, 3g of 3-carene, and 8g of fentanyl;

[0061] (1) α-pinene, β-pinene and 3-carene were prepared according to the above-mentioned dosage to obtain an attractant for the red liptin beetle. Fenone was added dropwise to a sterile absorbent cotton carrier according to the above-mentioned dosage to prepare a sustained-release repellent.

[0062] (2) Preparation and storage of lure and repellent: The lure was added to a 12-filament black polyethylene plastic bag containing degreased cotton and sealed with a sealing machine to obtain the lure. The repellent component was dripped onto a sterile degreased cotton carrier (same as in Example 1), then placed in a 12-filament black polyethylene plastic bag and sealed with a sealing machine to obtain a repellent slow-release bag. The prepared lure and repellent slow-release bag were sealed in aluminum foil and refrigerated at 4°C.

[0063] (3) Field application of repellents:

[0064] a) Experiment location: Saihanba Mechanical Forest Farm, Hebei Province.

[0065] b) Construction of the trap: The trap mainly consists of a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. The large and small plates are crossed to form a cross shape (500mm high, 300mm wide), connected to the top cover via a hook at the top, and connected to the funnel via a hook at the bottom. The flared opening for connecting the insect collection bottle is fitted over the lower part of the funnel and connected to the collection bottle.

[0066] c) Hanging position of lure and repellent: The combination of drugs is hung in the middle position 20cm from the top of the funnel-shaped bark beetle trap. The combination of drugs consists of one attractant and one repellent for the red turpentine bark beetle.

[0067] d) Field setup of the traps: Three replicates were set up for each experimental treatment. The traps were set up at the edge of the North China larch forest, with a spacing of about 100m between the traps. Two 3m long and 0.5cm thick wires were connected between the two trees, and the traps were then fixed in the middle of the wires. The insect collection bottle of the trap was 1m off the ground.

[0068] e) Data collection and trap emptying: Each treatment in this experiment was replicated three times, and the number of bark beetles captured in each treatment was the average of the three traps. Depending on the weather conditions, the number of bark beetles in the collection bottles was observed every 7 days. After counting, the collected bark beetles were placed in a plastic box and taken to the laboratory.

[0069] The application of the above-described specific steps for repelling the red turpentine beetle was carried out. From June 10th to July 5th, 2024, traps with blank lures (treatment 1) served as a blank control, while traps with plant-derived red turpentine beetle attractants (treatment 2) served as a positive control. Specific results are shown in [link to results]. Figure 2 The traps were spaced 100m apart, and the collection bottles were approximately 1m off the ground. Each treatment was replicated three times, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the collection bottles was observed every 5 days, depending on weather conditions.

[0070] Table 2. Effects of different doses of senna on the attraction of *Leptochloa crus-galli*.

[0071]

[0072] Analysis of insect-attracting effects (e.g.) Figure 2 As shown in Table 2, treatment 1 (blank treatment) failed to attract *Lysimachia rubiginosa*; treatment 2 (plant-derived attractant for *Lysimachia rubiginosa*) showed good attraction. When slow-release bags prepared with different amounts of fenestrate were used in combination with the attractant, it was found that the number of *Lysimachia rubiginosa* attracted gradually decreased with increasing fenestrate dosage, while treatments 4 and 5 significantly reduced the number of *Lysimachia rubiginosa* attracted, but the difference was not significant. From the perspectives of repellency and economic cost, 4g of fenestrate can significantly repel the aggregation behavior of *Lysimachia rubiginosa* in the field.

[0073] Example 3

[0074] Effects of fentanyl on the invasion behavior of red liptin beetle

[0075] The following four treatments are prepared according to the testing requirements:

[0076] Process 1: Blank handling;

[0077] Treatment 2: 4g of fentanyl;

[0078] (1) Prepare the repellent by preparing the fentanyl according to the above requirements.

[0079] (2) Preparation and storage of repellent: The repellent components in different proportions in (1) were dripped onto a sterile degreased cotton carrier (same as in Example 1), then placed in a 12-filament black polyethylene plastic bag, and sealed with a sealing machine to obtain a repellent slow-release bag. The prepared repellent slow-release bag was sealed with aluminum foil and refrigerated at 4°C.

[0080] (3) Field application of repellents:

[0081] a) Experiment time and location: Saihanba Mechanical Forest Farm, Hebei Province (May 10 - July 20, 2025);

[0082] b) Bait wood trapping: Select larch trees in North China that have been invaded by red turpentine beetle as bait wood to attract the red turpentine beetle.

[0083] c) Hanging position of the repellent: Fix the slow-release bag of repellent to the trunk of the affected North China larch tree 1m away with thin wire.

[0084] d) Statistical analysis of the entry pores of the red turpentine beetle before the experiment.

[0085] e) Field survey of repellency effect: Each treatment was replicated three times in this experiment. Two months later, the number of entry holes of the red turpentine beetle on each wood segment was counted.

[0086] Table 3. Effects of fentanyl on invasion by *Leptochloa crus-galli*.

[0087]

[0088] From the invasion holes on the trunks of North China larch trees in each treatment group ( Figure 3 (See Table 3). Statistical analysis revealed an average of 10.33 new invasion holes per affected tree segment (without repellent). When the repellent slow-release bag was fixed to the trunk, the invasion of *Larix rubrum* on the bait tree was significantly reduced, with only 2 invasion holes per segment on average under treatment 2 (fentanyl). This experiment demonstrates that, under field conditions, repellents prepared with fentanyl can reduce the infection of *Larix rubrum* trunks on *Larix chinensis* in North China.

[0089] In summary, the repellent for *Lysimachia rubiginosa* provided by this invention has a significant antagonistic effect on the aggregation behavior of *Lysimachia rubiginosa*, requires a low dosage, and can effectively reduce the infection rate of *Lysimachia rubiginosa* on host plants. The repellent for *Lysimachia rubiginosa* provided by this invention has a simple preparation process and application technology, making it suitable for large-scale promotion and application in production.

[0090] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A repellent for the red liptinous beetle, characterized in that, include: The slow-release carrier is a polyethylene plastic bag; Sterile degreased cotton placed inside the polyethylene plastic bag; The repellent component adsorbed on the sterile absorbent cotton is senna ketone; The content of fentanyl in a single repellent is 4g; The polyethylene plastic bag is made of low-density polyethylene with a mass percentage of 99%, a thickness of 12 mils, a length of 100mm, and a width of 50mm.

2. The repellent for red liptin beetles according to claim 1, characterized in that: The purity of the flavonoid is 98%.

3. The method for preparing the repellent for the red liptinous beetle according to claim 1 or 2, characterized in that, The procedure includes the following steps: 4g of fentanyl is added to sterile absorbent cotton, and then the sterile absorbent cotton with fentanyl is placed in the polyethylene plastic bag and sealed.

4. The use of the red turpentine beetle repellent according to claim 1 or 2 in repelling red turpentine beetles.

5. The application according to claim 4, characterized in that: The repellent for the red turpentine beetle was hung in the forest at a height of 1m, with a spacing of 100m between adjacent repellents.

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