A spruce beetle repellent and its preparation method and application

Abstract

The present invention relates to the technical field of green prevention and control of spruce eight-toothed beetle, and in particular to a spruce eight-toothed beetle repellent and its preparation method and application. The repellent component includes endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane. The present invention finds that exo-brevicomin and frontalin both have obvious repellent effects on spruce eight-toothed beetle, and exo-brevicomin and frontalin can be used in combination as a spruce eight-toothed beetle repellent, and repel spruce eight-toothed beetle to protect spruce forest ecosystems in production. The repellent has low dosage, stable repellent effect, environmental friendliness and broad industrialization prospects, and is particularly suitable for large-scale promotion in production.

Description

Technical Field

[0001] The invention relates to the technical field of green prevention and control of spruce beetles, in particular to a spruce beetle repellent and a preparation method and application thereof. Background Art

[0002] The spruce beetle (Ips typographus L.) is a major trunk-boring pest that harms spruce forests in Eurasia, and is particularly serious in spruce forests in Northeast and Northwest China. The spruce beetle primarily attacks snow-burdened trees, wind-fallen trees, and weakened trees, but when its population density is too high, it can still harm healthy spruce trees. For example, in 2022, the spruce forests in Yanji, Jilin Province, my country were hit by a typhoon. A large number of fallen trees bred tens of thousands of spruce beetles. In 2023, the population of spruce beetles increased sharply, posing a serious threat and damage to spruce forests. The adult activity period of spruce beetles is from early May to late August each year. During this period, male adults invade trees as pioneer species and release aggregation pheromones, which in turn attract a large number of spruce beetles to colonize the host plants. After mating, the male and female adults of the spruce beetle lay numerous eggs, which hatch into larvae that continue to feed on the phloem of spruce trees. In the wild, the beetle can complete a generation in about two months. Due to the damage done to the phloem, the spruce trees die within a short period of time. Given the beetle's tendency to aggregate and cause damage, a pheromone attractant has been developed and widely used for monitoring and killing the insect. The attractant is a binary compound consisting of 2-methyl-3-butene-2-ol and S-cis-verbenol. While this attractant kills a significant number of beetles annually, it does not protect host plants from attack by the beetle. Consequently, significant numbers of spruce trees still die annually due to beetle infestation.

[0003] In recent years, preliminary research has been conducted on repellents for the spruce beetle (Picea spp.) and their application technologies. Repellents are important information chemicals that hinder the aggregation and damage of spruce beetle populations and can interrupt the spruce beetle's aggregation and invasion of hosts. Song Liwen et al. (2012) reported that verbenone, trans-spiroacetal, and 1-hexanol can be used as repellents for the spruce beetle. Fang et al. (2021) found that the host component myrcene has a strong repellent effect on the spruce beetle, and some non-host volatiles, such as nonanal, also have a good repellent effect. Cheng Bin et al. (2022) reported a method for controlling the spruce beetle using a combination of a spruce beetle attractant and a spruce beetle repellent, forming a push-pull strategy for the control of the spruce beetle. Screening for behavioral repellents against the spruce beetle from host and non-host plants is the primary approach to repellent development. However, plant-derived repellent ingredients require high dosages, and repellents prepared from plant volatiles typically require high release rates to be effective. Therefore, developing repellents with low usage rates is crucial for the integrated control of the spruce beetle.

[0004] Numerous studies have demonstrated that pheromones from different bark beetles exhibit significant antagonistic effects. For example, Schlyter et al. (2015) found that trans-verbenol, a component of the aggregation pheromone of the nitidus, has a repellent effect on the Shangri-la bark beetle, I. shangrila, preventing resource competition between the two species. Furthermore, the use of this component in the field is far lower than that of plant-based repellents. This demonstrates the theoretical and practical feasibility of developing repellents based on bark beetle pheromones. Furthermore, the prepared repellents use a relatively low amount of active ingredients, aligning with the fundamental principle of low-cost and high-efficiency pheromone use. However, there are currently few reports and application examples of the use of bark beetle pheromones as repellents. The repellents developed and prepared based on this approach have high practical value in repelling or disrupting the damage caused by the spruce bark beetle to its host plant, spruce, and contribute to the development of a comprehensive control system for the spruce bark beetle. Summary of the Invention

[0005] To address the above issues, the present invention provides a spruce beetle repellent, its preparation method, and its application, for repelling or disrupting the aggregation of spruce beetle populations in forests. The repellent can be affixed to spruce tree trunks, effectively repelling the spruce beetle's aggregation and protecting the host spruce from harm.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides the use of a repellent component in preventing and controlling damage caused by spruce borer in forests. The repellent component comprises endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane.

[0008] Preferably, the mass ratio of the endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane to (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane is 10:1.

[0009] The present invention also provides a spruce beetle repellent, comprising a repellent component, a cuff-type composite rubber stopper and a polyethylene plastic bag;

[0010] The repellent component includes endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane.

[0011] Preferably, each cuff-type composite rubber stopper contains 200 mg of endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane.

[0012] Preferably, each cuff-type composite rubber stopper contains 20 mg of (1S, 5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane.

[0013] Preferably, each cuff-type composite rubber stopper contains 20 mg of (1S, 5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane and 200 mg of endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane.

[0014] Preferably, the material of the cuff-type composite rubber stopper is chlorobutyl rubber and natural rubber, and the mass ratio of the chlorobutyl rubber to the natural rubber is 3-7:3-7; the specifications of the cuff-type composite rubber stopper are: length 18.4mm±0.2mm; cross-sectional diameter 1 8.9mm±0.2mm; cross-sectional diameter 2 5.5mm±0.2mm; cross-sectional diameter 3 4.6mm±0.2mm; depth 8.6mm±0.2mm; small head length: 7.5mm±0.2mm; weight 0.60g±0.05g;

[0015] The polyethylene plastic bag is 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.

[0016] The present invention also provides a method for preparing the spruce beetle repellent described in the above technical solution, comprising the following steps: dripping the repellent component onto a cuff-type composite rubber plug carrier, then placing it in a polyethylene plastic bag and sealing it.

[0017] The present invention also provides a use of the spruce beetle repellent described in the above technical solution in preventing and controlling the damage caused by the spruce beetle in the forest.

[0018] Preferably, the spruce beetle repellent is hung in the forest at a height of 1 m and a spacing of 30 m.

[0019] The beneficial effects of the present invention are:

[0020] (1) Used to repel spruce beetles, prevent spruce beetles from gathering and causing harm on the host, and reduce the damage rate of the host spruce: Since the spruce beetle repellent attractant core of the present invention has high repellent biological activity, it can be used in healthy forests to repel low-density spruce beetles inside the forest and prevent them from gathering and causing harm on trees.

[0021] (2) Used to hinder the sexual mating and population spread of the spruce eight-toothed beetle. The repellent of the present invention has a highly efficient repellent activity and produces a significant antagonistic effect on the aggregation pheromone with sexual mating activity. Use in the forest can reduce the sexual mating of the spruce eight-toothed beetle, thereby regulating the population density; secondly, it can significantly inhibit the population spread of the spruce eight-toothed beetle. Setting a repellent belt at the edge of the forest where the damage is more serious can prevent the spruce eight-toothed beetle from escaping to the healthy forest. At the same time, it can be used in combination with an attractant to form a "push-pull" prevention and control, which can meet the production protection of key forest areas. The technology is simple and fast to operate and does not require much manpower.

[0022] The spruce beetle repellent provided by the present invention adopts a cuff-type composite rubber stopper and a 12-filament black polyethylene plastic bag as a carrier, is easy to process and produce, has low cost, and the two repellent ingredients can be stably released on the slow-release carrier, and the lasting effect can be maintained at 50 days, which can meet the needs of actual production. The repellent of the present invention is an efficient and long-lasting spruce beetle repellent, and the invention is an environmentally friendly green biotechnology that can be used to repel the aggregation and invasion of spruce beetles, thereby achieving the effect of protecting spruce forests. The repellent was tested in the Jingouling Forest Farm of the Wangqing Forestry Bureau in Jilin Province, and its good repellent activity and stability were verified. The spruce beetle repellent of the present invention has broad industrial prospects. In addition, its preparation process is simple, which is conducive to large-scale promotion in production. In summary, the repellent of the present invention has the advantages of low dosage, environmental friendliness, long duration and low price. It can protect the host spruce by interfering with or cutting off the aggregation and invasion of the spruce eight-toothed borer through the long-term slow release of the repellent.

[0023] Endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane is hereinafter referred to as exo-brevicomin, and (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane is hereinafter referred to as frontalin. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below.

[0025] Figure 1 Results of a behavioral test of various bark beetle pheromones on the spruce eight-toothed bark beetle in May 2022;

[0026] Figure 2 This is a test on the inhibitory effect of different doses of exo-brevicomin on the spruce eight-toothed beetle in June 2022;

[0027] Figure 3 This is a test on the inhibitory effect of different doses of frontalin on the spruce eight-toothed beetle in June 2022;

[0028] Figure 4 This is a test on the inhibition of spruce borer by two repellents and their different ratios from June to July 2023;

[0029] Figure 5 This is the effect of two repellents and their optimal ratios on the invasion behavior of spruce borer in May 2023. DETAILED DESCRIPTION

[0030] The present invention provides the use of a repellent component for controlling damage caused by the spruce beetle in forests. The repellent component includes endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane. In the present invention, when the repellent components are both endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane, their mass ratio is preferably 10:1. Sources and purity (mass %) of the above two repellent ingredients: endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane exo-brevicomin (CAS: 62532-53-0, Acros Organics, 95%), (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane frontalin (CAS: 28401-39-0, TCI (Shanghai) Chemical Trading Co., Ltd., 95%).

[0031] The present invention provides a spruce beetle repellent, comprising a repellent component, a cuff-type composite rubber stopper, and a polyethylene plastic bag; the repellent component comprises endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane. In the present invention, each cuff-type composite rubber stopper preferably contains 200 mg of endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane. In the present invention, each cuff-type composite rubber stopper preferably contains 20 mg of (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane. In the present invention, each cuff-type composite rubber stopper preferably contains 20 mg of (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane and 200 mg of endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane. In the present invention, the cuff-type composite rubber stopper is preferably made of chlorinated butyl rubber and natural rubber, and the mass ratio of the chlorinated butyl rubber to natural rubber is preferably 3-7:3-7. The specifications of the cuff-type composite rubber stopper are: length 18.4 mm ± 0.2 mm; cross-sectional diameter 1 8.9 mm ± 0.2 mm; cross-sectional diameter 2 5.5 mm ± 0.2 mm; cross-sectional diameter 3 4.6 mm ± 0.2 mm; depth 8.6 mm ± 0.2 mm; small end length: 7.5 mm ± 0.2 mm; weight 0.60 g ± 0.05 g. In the present invention, the polyethylene plastic bag is preferably 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.

[0032] The present invention also provides a method for preparing the spruce beetle repellent described in the above technical solution, comprising the following steps: dripping the repellent component onto a cuff-type composite rubber plug carrier, then placing it in a polyethylene plastic bag and sealing it.

[0033] The present invention also provides the use of the spruce beetle repellent according to the above technical solution in preventing and controlling the damage caused by the spruce beetle in the forest. In the present invention, the spruce beetle repellent is preferably hung in the forest at a height of 1m and a spacing of 30m.

[0034] The spruce beetle attractants prepared in the following examples all use commercially available 2-methyl-3-butene-2-ol and S-cis-verbenol, and their chemical purity and isomeric purity are both greater than 97%; the repellents use commercially available exo-brevicomin and frontalin, and their chemical purity and isomeric purity are both greater than 95%; and commercially available seudenol, myrcenol, and trans-verbenol are used, and their chemical purity and isomeric purity are both greater than 95%.

[0035] In order to further illustrate the present invention, the present invention is described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0036] Example 1

[0037] Results of behavioral tests on the spruce beetle (Pseudosphagidae) using various bark beetle pheromones

[0038] The spruce beetle attractant prepared in this embodiment uses commercially available 2-methyl-3-butene-2-ol and S-cis-verbenol, whose chemical purity and isomeric purity are both greater than 97%; and uses commercially available exo-brevicomin, frontalin, seudenol, myrcenol, and trans-verbenol, whose chemical purity and isomeric purity are both greater than 95%.

[0039] The following 7 treatments were prepared according to test requirements.

[0040] Treatment 1: blank treatment;

[0041] Treatment 2: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg;

[0042] Treatment 3: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 20 mg;

[0043] Treatment 4: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, frontalin 20 mg;

[0044] Treatment 5: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, seudenol 20 mg;

[0045] Treatment 6: 2-methyl-3-buten-2-ol 4 g, S-cis-verbenol 40 mg, trans-verbenol 20 mg;

[0046] Treatment 7: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, myrcenol 20 mg;

[0047] (1) 4 g of 2-methyl-3-butene-2-ol and S-cis-verbenol were prepared in the aforementioned amounts to obtain an attractant for the spruce beetle. Exo-brevicomin, frontalin, seudenol, myrcenol, and trans-verbenol were added dropwise in the aforementioned amounts to a cuff-type composite rubber plug carrier to prepare a slow-release repellent.

[0048] (2) Preparation and storage of lures and repellents: The lures were added to a 12-filament black polyethylene plastic bag containing absorbent cotton and sealed with a sealing machine to obtain the lures. The repellent components were added dropwise to a cuff-type composite rubber plug carrier, which was then placed in a 12-filament black polyethylene plastic bag and sealed with a sealing machine to obtain a repellent slow-release bag. The cuff-type composite rubber plug was made of chlorobutyl rubber and natural rubber, with a mass ratio of chlorobutyl rubber to natural rubber of 3-7:3-7. The specifications were: length 18.4 mm; cross-sectional diameter 1 8.9 mm; cross-sectional diameter 2 5.5 mm; cross-sectional diameter 3 4.6 mm; depth 8.6 mm; small end length: 7.5 mm; weight 0.60 g. The polyethylene plastic bag was made of 99% low-density polyethylene by mass, with a thickness of 12 filaments, a length of 100 mm, and a width of 50 mm. The lures and repellent slow-release bags were sealed with aluminum foil and refrigerated at 4°C.

[0049] (3) Field application of repellent:

[0050] a) Experimental location: Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province.

[0051] b) Trap Fabrication: The trap is primarily a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. A large plate and a small plate are intersected to form a cross (500 mm high, 300 mm wide). This is connected to the upper cover via a hook at the top and to the funnel via a hook at the bottom. The bell-shaped mouthpiece for connecting to the insect collection bottle is placed under the funnel and the insect collection bottle is connected.

[0052] c) Hanging position of the attractant and repellent: Hang the agent combination in the middle position 20 cm from the top of the funnel-shaped bark beetle trap. The agent combination is 1 spruce eight-toothed bark beetle attractant and 1 repellent (open the aluminum foil before use to obtain a repellent slow-release bag).

[0053] d) Field trap placement: Each experimental treatment was replicated three times. Traps were set at the edge of a spruce forest, approximately 30 meters apart. Two 3-meter-long, 0.5-cm-thick wires were connected between two trees. The trap was then secured between the wires, with the trap jar elevated 1 meter above the ground.

[0054] e) Data Collection and Trap Emptying: Each treatment was replicated three times. The number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions. After counting, the trapped bark beetles were placed in plastic boxes and brought to the laboratory.

[0055] According to the above specific use steps, the application of the method for repelling the spruce beetle was carried out. From May 1 to May 27, 2022, the trap with a blank lure (treatment 1) was used as a blank control, and the trap with the spruce beetle aggregation pheromone attractant (treatment 2) was used as a positive control. The specific results are shown in Tables 1 and Figure 1 Traps were spaced 30 meters apart, with the traps approximately 1 meter above the ground. Three replicates were set for each treatment in this experiment, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions.

[0056] Table 1 Effects of various pheromone components of bark beetles on the aggregation pheromone trapping of the spruce beetle

[0057] Repeat 1 Repeat 2 Repeat 3 Average number of traps (head) Process 1 0 0 0 0 Process 2 82 70 64 72 Process 3 12 23 14 16.3 Process 4 27 19 16 20.6 Process 5 38 37 56 43.6 Process 6 55 69 72 65.3 Process 7 79 91 59 76.3

[0058] From Table 1 and Figure 1 It can be concluded that from the analysis of the attractant effect, the blank treatment (treatment 1) has no attractant activity for the spruce beetle, while the spruce beetle aggregation pheromone attractant (treatment 2) has a good attractant effect. The spruce beetle attractant (treatments 3, 4, and 5) reduced the amount of spruce beetles attracted compared to treatment 2, but treatments 3 and 4 had the greatest impact on the amount of spruce beetles trapped. Treatments 6 and 7 had no significant effect on the attractant effect of spruce beetles. This experiment shows that when the spruce beetle aggregation pheromone attractant is used in combination with exo-brevicomin or frontalin, exo-brevicomin and frontalin can significantly reduce the amount of trapping by 2.5-3.5 times, indicating that exo-brevicomin and frontalin are antagonists of the aggregation of spruce beetle populations.

[0059] Example 2

[0060] Experiment on the inhibitory effect of different doses of exo-brevicomin on spruce beetle

[0061] Prepare the following 5 treatments according to test requirements:

[0062] Treatment 1: blank treatment;

[0063] Treatment 2: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg;

[0064] Treatment 3: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 2 mg;

[0065] Treatment 4: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 20 mg;

[0066] Treatment 5: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 200 mg;

[0067] (1) 4 g of 2-methyl-3-butene-2-ol and S-cis-verbenol were prepared according to the above amounts to obtain an attractant for the spruce beetle. Exo-brevicomin was added dropwise to a cuff-type composite rubber plug carrier according to the above amounts to prepare a slow-release repellent.

[0068] (2) Preparation and Storage of Lure and Repellent: The attractant was added to a 12-filament black polyethylene plastic bag containing absorbent cotton and sealed with a sealing machine to obtain a lure. The repellent component was added dropwise to a cuff-type composite rubber stopper carrier (same as in Example 1), which was then placed in a 12-filament black polyethylene plastic bag and sealed with a sealing machine to obtain a repellent sustained-release bag. The prepared lure and repellent sustained-release bag were sealed with aluminum foil and refrigerated at 4°C.

[0069] (3) Field application of repellent:

[0070] a) Experimental location: Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province.

[0071] b) Trap Fabrication: The trap is primarily a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. A large plate and a small plate are intersected to form a cross (500 mm high, 300 mm wide). This is connected to the upper cover via a hook at the top and to the funnel via a hook at the bottom. The bell-shaped mouthpiece for connecting to the insect collection bottle is placed under the funnel and the insect collection bottle is connected.

[0072] c) Hanging position of the lure and repellent: Hang the combination of medicaments, one attractant and one repellent, in the middle of the funnel-shaped bark beetle trap, 20 cm from the top.

[0073] d) Field trap placement: Each experimental treatment was replicated three times. Traps were set at the edge of a spruce forest, approximately 30 meters apart. Two 3-meter-long, 0.5-cm-thick wires were connected between two trees. The trap was then secured between the wires, with the trap jar elevated 1 meter above the ground.

[0074] e) Data Collection and Trap Emptying: Each treatment was replicated three times. The number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions. After counting, the trapped bark beetles were placed in plastic boxes and brought to the laboratory.

[0075] According to the above specific use steps, it is used to repel spruce beetles. From June 1 to June 25, 2022, the trap with a blank bait core (treatment 1) was used as a blank control, and the trap with spruce beetle aggregation pheromone attractant (treatment 2) was used as a positive control. The specific results are shown in Figure 2 Traps were spaced 30 meters apart, with the traps approximately 1 meter above the ground. Three replicates were set for each treatment in this experiment, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions.

[0076] Table 2 Effects of different doses of exo-brevicomin on the aggregation pheromone trapping of the spruce beetle

[0077] Repeat 1 Repeat 2 Repeat 3 Average number of traps (head) Process 1 0 0 0 0 Process 2 85 97 95 92.3 Process 3 50 38 40 42.6 Process 4 29 25 20 24.6 Process 5 22 17 26 21.3

[0078] From the analysis of insect attraction effect (such as Figure 2 As shown in Table 2, treatment 1 (blank treatment) failed to attract the spruce beetle, while treatment 2 (spruce beetle aggregation pheromone attractant) exhibited a good attracting effect. When slow-release bags prepared with varying exo-brevicomin dosages were used in conjunction with the attractants, the capture rate of the spruce beetle gradually decreased with increasing exo-brevicomin dosage. Treatments 4 and 5 significantly reduced the capture rate, but the difference between the two treatments was not significant. In terms of repellency and economic investment, 20 mg of exo-brevicomin can significantly repel the aggregation behavior of spruce beetles in the wild.

[0079] Example 3

[0080] Experiment on the inhibitory effect of different doses of frontalin on spruce beetle

[0081] Prepare the following 5 treatments according to test requirements:

[0082] Treatment 1: blank treatment;

[0083] Treatment 2: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg;

[0084] Treatment 3: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, frontalin 2 mg;

[0085] Treatment 4: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, frontalin 20 mg;

[0086] Treatment 5: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, frontalin 200 mg;

[0087] (1) 4 g of 2-methyl-3-butene-2-ol and S-cis-verbenol were prepared according to the above usage amounts to obtain an attractant for the spruce beetle. Frontalin was added dropwise according to the above usage amounts onto a cuff-type composite rubber plug carrier to prepare a slow-release repellent.

[0088] (2) Preparation and Storage of Lure and Repellent: The attractant was added to a 12-filament black polyethylene plastic bag containing absorbent cotton and sealed with a sealing machine to obtain a lure. The repellent component was added dropwise to a cuff-type composite rubber stopper carrier (same as in Example 1), which was then placed in a 12-filament black polyethylene plastic bag and sealed with a sealing machine to obtain a repellent sustained-release bag. The prepared lure and repellent sustained-release bag were sealed with aluminum foil and refrigerated at 4°C.

[0089] (3) Field application of lures and repellents:

[0090] a) Experimental location: Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province.

[0091] b) Trap Fabrication: The trap is primarily a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. A large plate and a small plate are intersected to form a cross (500 mm high, 300 mm wide). This is connected to the upper cover via a hook at the top and to the funnel via a hook at the bottom. The bell-shaped mouthpiece for connecting to the insect collection bottle is placed under the funnel and the insect collection bottle is connected.

[0092] c) Hanging position of the lure: Hang the pesticide combination in the middle position 20 cm away from the top of the funnel-shaped bark beetle trap. The pesticide combination consists of one spruce eight-toothed bark beetle attractant and one repellent.

[0093] d) Field trap placement: Each experimental treatment was replicated three times. Traps were set at the edge of a spruce forest, approximately 30 meters apart. Two 3-meter-long, 0.5-cm-thick wires were connected between two trees. The trap was then secured between the wires, with the trap jar elevated 1 meter above the ground.

[0094] e) Data Collection and Trap Emptying: Each treatment was replicated three times. The number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions. After counting, the trapped bark beetles were placed in plastic boxes and brought to the laboratory.

[0095] According to the above specific use steps, it is used to repel spruce beetles. From June 1 to June 25, 2022, the trap with a blank bait core (treatment 1) was used as a blank control, and the trap with spruce beetle aggregation pheromone attractant (treatment 2) was used as a positive control. The specific results are shown in Figure 3 Traps were spaced 30 meters apart, with the traps approximately 1 meter above the ground. Three replicates were set for each treatment in this experiment, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions.

[0096] Table 3 Effects of different doses of frontalin on the aggregation pheromone trapping of the spruce beetle

[0097]

[0098]

[0099] From the analysis of insect attraction effect (such as Figure 3 As shown in Table 3, treatment 1 (blank treatment) failed to attract the spruce beetle, while treatment 2 (spruce beetle aggregation pheromone attractant) exhibited a good attracting effect. When slow-release bags prepared with different amounts of frontalin were used in combination with the attractants, the number of spruce beetle captures gradually decreased with increasing frontalin dosage. Treatments 4 and 5 significantly reduced the number of spruce beetle captures, but the difference between the two treatments was not significant. In terms of repellency and economic investment, 20 mg of frontalin can significantly repel the aggregation behavior of spruce beetles in the wild.

[0100] Example 4

[0101] Inhibitory test of two repellents and their different ratios on spruce beetle

[0102] Prepare the following 5 treatments according to test requirements:

[0103] Treatment 1: blank treatment;

[0104] Treatment 2: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg;

[0105] Treatment 3: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 5 mg, frontalin 15 mg;

[0106] Treatment 4: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 10 mg, frontalin 10 mg;

[0107] Treatment 5: 2-methyl-3-buten-2-ol 4 g and S-cis-verbenol 40 mg, exo-brevicomin 15 mg, frontalin 5 mg;

[0108] (1) 4 g of 2-methyl-3-butene-2-ol and S-cis-verbenol were prepared according to the above-mentioned usage amounts to obtain an attractant for the spruce beetle. Exo-brevicomin and frontalin were added dropwise according to the above-mentioned usage amounts to a cuff-type composite rubber plug carrier to prepare a slow-release repellent.

[0109] (2) Preparation and Storage of Lure and Repellent: The attractant was added to a 12-filament black polyethylene plastic bag containing absorbent cotton and sealed with a sealing machine to obtain a lure. The repellent component was added dropwise to a cuff-type composite rubber stopper carrier (same as in Example 1), which was then placed in a 12-filament black polyethylene plastic bag and sealed with a sealing machine to obtain a repellent sustained-release bag. The prepared lure and repellent sustained-release bag were sealed with aluminum foil and refrigerated at 4°C.

[0110] (3) Field application of lures:

[0111] a) Experimental location: Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province.

[0112] b) Trap Fabrication: The trap is primarily a funnel-shaped bark beetle trap, purchased from Beijing Zhongjie Sifang Biotechnology Co., Ltd. A large plate and a small plate are intersected to form a cross (500 mm high, 300 mm wide). This is connected to the upper cover via a hook at the top and to the funnel via a hook at the bottom. The bell-shaped mouthpiece for connecting to the insect collection bottle is placed under the funnel and the insect collection bottle is connected.

[0113] c) Hanging position of the lure and repellent: Hang the combination of medicaments, one attractant and one repellent, in the middle of the funnel-shaped bark beetle trap, 20 cm from the top.

[0114] d) Field trap placement: Each experimental treatment was replicated three times. Traps were set at the edge of a spruce forest, approximately 30 meters apart. Two 3-meter-long, 0.5-cm-thick wires were connected between two trees. The trap was then secured between the wires, with the trap jar elevated 1 meter above the ground.

[0115] e) Data Collection and Trap Emptying: Each treatment was replicated three times. The number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions. After counting, the trapped bark beetles were placed in plastic boxes and brought to the laboratory.

[0116] According to the specific use steps above, it is used to repel the spruce beetle. From May 27 to July 17, 2023, the trap with a blank bait core (treatment 1) was used as a blank control, and the trap with the spruce beetle aggregation pheromone attractant (treatment 2) was used as a positive control. The specific results are shown in Figure 4 Traps were spaced 30 meters apart, with the traps approximately 1 meter above the ground. Three replicates were set for each treatment in this experiment, and the number of bark beetles captured in each treatment was the average of the three traps. The number of bark beetles in the traps was observed every five days, depending on weather conditions.

[0117] Table 4 Effects of different ratios of exo-brevicomin and frontalin on the aggregation pheromone trapping of the spruce beetle

[0118] Repeat 1 Repeat 2 Repeat 3 Average number of traps (head) Process 1 0 0 0 0 Process 2 152 135 138 141.6 Process 3 34 42 43 39.6 Process 4 21 33 31 28.3 Process 5 29 33 27 29.6

[0119] From the analysis of insect attraction effect (such as Figure 4 As shown in Table 4, Treatment 1 (blank treatment) failed to attract the spruce beetle, while Treatment 2 (spruce beetle aggregation pheromone attractant) exhibited a good attractant effect. This experiment demonstrates that when slow-release bags prepared with different ratios of exo-brevicomin and frontalin are used in combination with attractants, it is found that regardless of the ratio, the agents exhibited a significant antagonistic effect against the spruce beetle aggregation pheromone attractant, with little difference in repellent effect between the different ratios.

[0120] Example 5

[0121] Effects of two repellents and their optimal ratios on the invasion behavior of the spruce beetle

[0122] Prepare the following four treatments according to test requirements:

[0123] Treatment 1: blank treatment;

[0124] Treatment 2: exo-brevicomin 20 mg;

[0125] Treatment 3: frontalin 20 mg;

[0126] Treatment 4: exo-brevicomin 10 mg, frontalin 10 mg;

[0127] (1) Exo-brevicomin and frontalin are prepared according to the above ratios to obtain repellents with different ratios.

[0128] (2) Preparation and Storage of Repellent: The repellent components in different proportions described in (1) were added dropwise to a cuff-type composite rubber stopper carrier (same as in Example 1), 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 core and repellent slow-release bag were sealed with aluminum foil and refrigerated at 4°C.

[0129] (3) Field application of repellent:

[0130] a) Experimental time and location: Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province (May 10-20, 2024);

[0131] b) Bait wood trapping: Cut wind-fallen red spruce into 50 cm sections and use them as bait wood to attract spruce eight-toothed borer.

[0132] c) Hanging position of repellent: Use thin wire to fix the repellent slow-release bag in the middle of the wood section.

[0133] d) Field Setup and Data Collection: Wood segments from different treatment groups were placed in a well-lit area. Three replicates were set up for each treatment. After 10 days of field placement, the number of holes infiltrated by the spruce beetle was counted on each segment.

[0134] Table 5 Effects of exo-brevicomin and frontalin and their optimal ratios on the invasion of spruce borer

[0135] Repeat 1 Repeat 2 Repeat 3 Average number of intrusion holes Process 1 55 42 46 47.6 Process 2 9 6 7 7.3 Process 3 8 10 11 9.6 Process 4 4 6 5 5

[0136] From the invasion space on the wood sections of each treatment group ( Figure 5(and Table 5) For wood segments without repellent, statistics revealed an average of 48 intrusion holes per segment. However, when the repellent slow-release bags were attached to the trunks, intrusion by the spruce beetle on the bait wood was significantly reduced. Treatment 2 (exo-brevicomin) resulted in an average of only 7 intrusion holes per segment, treatment 3 (frontalin) resulted in an average of 10 intrusion holes per segment, and treatment 4 (10 mg each of exo-brevicomin and frontalin) resulted in an average of 5 intrusion holes per segment. This experiment demonstrates that repellents prepared from exo-brevicomin, frontalin, and their mixture can reduce infestation of spruce beetles on spruce trunks under field conditions.

[0137] In summary, the spruce beetle repellent provided by the present invention has a significant antagonistic effect on the aggregation behavior of the spruce beetle, is used in a low dosage, and can effectively reduce the spruce beetle's infection rate on host spruce. The spruce beetle repellent provided by the present invention has a simple preparation process and simple application technology, and is suitable for large-scale promotion and application in production.

[0138] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. The use of repellent ingredients in preventing and controlling damage caused by spruce borer in forests, the repellent ingredients comprising endo-(-)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane and / or (1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane.

Images