Pheromone temperature response electrospun nanofiber of dendroctonus valerieus, and preparation method and lure of pheromone temperature response electrospun nanofiber

Abstract

The invention discloses a dendroctonus valerieus pheromone temperature response electrospun nanofiber as well as a preparation method and a lure thereof. The preparation method comprises the following steps: A, mixing dichloromethane and paraffin to obtain a solution A; b, adding polyhydroxybutyrate and pheromone 3-carene in the solution A, and stirring and dissolving the polyhydroxybutyrate and the pheromone 3-carene in the solution A to obtain a solution B; and C, carrying out electrostatic spinning on the solution B to obtain the temperature response electrospun nanofiber of the dendroctonus valerieus pheromone. The paraffin is added into the formula aiming at the rhythm that the dendroctonus valerieus is going out in the daytime, intelligent luring can be performed, the paraffin is dissolved at high temperature in the daytime so as to release the attractant in a concentrated manner, the temperature is reduced at night, and the paraffin releases the attractant in a closed manner, so that the use efficiency of the luring core is improved, and the woodland application time is prolonged; the effect persistence is improved while the attraction efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of PHB nanofibers and invasive pest control, and comprises a nanofiber slow-release material with temperature-sensitive response characteristics and a preparation method thereof, which provides a new design idea and a feasible solution for a pheromone intelligent slow-release carrier for target pests. Background Art

[0002] Insect pheromones are chemical signal molecules used in insect populations for sexual attraction, mating, aggregation, territory marking, and alarm. These pheromones are usually secreted by specific glands of insects and spread in the air to regulate the directional behavior of other individuals of the same species. Insect pheromones can be used as a biological control method to reduce dependence on chemical pesticides, thereby reducing environmental pollution. By reducing the use of chemical pesticides, non-target species can be protected, the balance of the ecosystem can be maintained, and target pests can be accurately attracted and controlled to improve control efficiency. The research and application of insect pheromones are of great significance in the fields of agriculture, ecology, and pest control, and are one of the current technical measures for green control of crop pests.

[0003] Pheromone compounds are easily degraded in the natural environment, resulting in unstable effects and short duration. Bio-nanofibers can act as a protective layer to encapsulate and stabilize pheromone compounds, extending their shelf life in the environment. PHB nanofibers are designed as carriers with a specific release mechanism - temperature response, which enables pheromone compounds to be precisely released at a specific time and place. This precise control can improve the effectiveness of prevention and control, reduce the impact on non-target species, and prolong the duration of action of attractants, thereby reducing the manpower and material costs caused by replacement. Nanofibers are usually made of natural or degradable materials, such as proteins, polysaccharides and lipids, which have less impact on the environment and organisms.

[0004] PHB nanofibers can be degraded by microorganisms in the natural environment and will not cause long-term pollution to the environment, which meets the requirements of sustainable development. Traditional insect pheromone carriers may use non-degradable materials, causing environmental pollution. The use of PHB nanofibers can significantly reduce this pollution. PHB has good biocompatibility and will not harm non-target organisms, ensuring the safety of the ecosystem. The nanofiber structure has an extremely high specific surface area, which can effectively adsorb and release insect pheromones and improve the utilization efficiency of pheromones. PHB nanofibers have good mechanical strength and flexibility and are suitable for the manufacture of insect pheromone carriers of various shapes and sizes. PHB nanofibers can be used as intelligent slow-release carriers by adding paraffin to control the release rate of insect pheromones, prolong the action time of pheromones, improve the prevention and control effect, and protect pheromones from the influence of the external environment to ensure the stability and activity of pheromones. Summary of the invention

[0005] The technical problem solved by the present invention is to provide temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone and a preparation method and an attractant core thereof. The preparation method has stable process, short preparation cycle, easy-to-control conditions and strong operability.

[0006] The temperature-responsive electrospun nanofibers of Dendroctonus rubrum pheromone of the present invention are prepared by the following method, comprising the following steps:

[0007] A. Mix dichloromethane and paraffin to obtain solution A;

[0008] B. Add polyhydroxybutyrate and Dendroctonus rubrum pheromone 3-carene into solution A, stir and dissolve to obtain solution B;

[0009] C. Electrospin solution B to obtain temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone.

[0010] Preferably, the specific steps are:

[0011] A. Mix dichloromethane and paraffin in a mass ratio of 6:4 to obtain solution A;

[0012] B. Add polyhydroxybutyrate and 3-carene to solution A at a mass volume ratio of 0.7 g::2.34 g:15 ml, stir and dissolve to obtain solution B;

[0013] C. Electrospinning solution B to obtain temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone. Preferably, solution B is injected into a syringe pump, and then the power is turned on for electrospinning, the flow rate is 4 ml / h, the distance from the syringe needle to the receiving device is adjusted to 10 cm, the voltage of the high-voltage power supply is 15 kV, the temperature of the receiving device is set to 75 ° C, the drum speed is 500 r / min, after electrospinning, a uniform white fiber film is collected on the hand screen drum, the polyester fiber film is torn off, and vacuum dried at room temperature to obtain temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone;

[0014] The temperature-responsive electrospun nanofibers of the pheromone of Dendroctonus rubrum were cut into bait chips of 2cm x 2cm to 5cm x 5cm, which were used to lure the adults of Dendroctonus rubrum in the forest to achieve the purpose of population dynamics monitoring and prevention and control.

[0015] The present invention also provides an attractant for attracting Dendroctonus rubrum, which uses the temperature-responsive electrospun nanofiber of the Dendroctonus rubrum pheromone as the attractant.

[0016] The size of the lure core is obtained by cutting the temperature-responsive electrospun nanofibers of the pheromone of Dendroctonus rubrum into lure chips of 2cm x 2cm to 5cm x 5cm.

[0017] The present invention also provides a trap for Dendroctonus rubrum, which comprises the above-mentioned attractant core.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0019] The present invention utilizes the rhythmic behavior of Dendroctonus rubrum to embed pheromones in polyhydroxybutyrate polymer materials, and utilizes nano-scale natural pore channels and the temperature response characteristics of paraffin to control the release of pheromones, which has the advantages of long sustained-release period and low cost.

[0020] The present invention aims at the rhythm of Dendroctonus ruber beetles going out during the day, and adds paraffin to the formula, so that intelligent lure can be carried out. During the day, the paraffin dissolves at high temperature to release the attractant in a concentrated manner. At night, the temperature drops and the paraffin seals and releases the attractant, thereby improving the efficiency of the lure core, extending the application time in the forest, improving the lure efficiency and improving the lasting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope image (SEM) of the PHB nanofibers prepared in the present invention;

[0022] Figure 2 The contact angle diagram of the PHB nanofiber prepared by the present invention;

[0023] Figure 3 This is a diameter distribution diagram of PHB nanofibers prepared in the present invention;

[0024] Figure 4 The PHB nanofiber prepared by the present invention is effective in trapping Dendroctonus rubrum in the forest;

[0025] Figure 5 The linear regression statistical result between the capture amount of Dendroctonus rubrum beetle by the PHB nanofiber prepared in the present invention and the average temperature of the day. DETAILED DESCRIPTION

[0026] The following examples are provided to further illustrate the present invention, rather than to limit the present invention.

[0027] Example 1

[0028] 1) In July 2024, materials were prepared at the Institute of Zoology, Guangdong Academy of Sciences, and 0.7 g of polyhydroxybutyrate polymer material and 2.34 g of pheromone compound 3-carene were weighed.

[0029] 2) Mix the two evenly, put into 15 ml of dichloromethane solution / paraffin with a mass ratio of 6:4, and stir overnight at 500 r / min in a 20 ml beaker to obtain an electrospinning solution.

[0030] 3) Preparation of the electrospinning apparatus: adjust the distance between the needle and the collection bucket to 10 cm; the humidity in the apparatus to 40%; the temperature to 75° C.; select a circular needle shape for the spinneret.

[0031] 4) Inject 15 ml of electrospinning solution into a syringe and install it on a 20 ml syringe pump, then turn on the power supply for electrospinning, the flow rate is 4 ml / h, the distance from the syringe needle to the receiving device is adjusted to 10 cm, the voltage of the high-voltage power supply is 15 kV, the temperature of the receiving device is set to 75 ° C, and the drum speed is 500 r / min;

[0032] 5) Apply a high voltage of 15kv, and the solution is transformed into a charged jet stream under the action of the high voltage, and the jet stream is deposited on the surface of the substrate. The polymer in the jet stream solidifies to form nanofibers, and finally forms a white film under natural light. After tearing off the polyester fiber film, it is vacuum dried at room temperature to finally obtain a film of about 30cm×40cm in size, and the PHB nanofiber or fiber film is prepared. The PHB nanofiber is cut into 2cm x 2cm to 5cm x 5cm bait chips, and the red lip beetle adults are lured in the forest to achieve the purpose of population dynamic monitoring and prevention and control.

[0033] Scanning electron microscopy image of PHB nanofibers Figure 1 As shown. The SEM image clearly shows the uniformly distributed mesh structure of PHB nanofibers, which has good visual consistency and integrity. Through SEM measurements, it can be observed that the diameter of PHB nanofibers is between 4.33±0.53μm, and the fiber diameter distribution is relatively uniform, reflecting good preparation process control. The surface of the fiber membrane is smooth and has a specific texture. This surface morphology has an important influence on the high-temperature specific release performance. In the SEM image, it can be clearly seen that there are abundant pores in the PHB nanofiber membrane. The presence of pores provides channels and space for the release and storage of pheromones of Dendroctonus erythrorhizium.

[0034] The contact angle of PHB nanofibers is Figure 2 As shown. The contact angle diagram taken based on the PHB nanofiber membrane intuitively shows the surface wettability characteristics of paraffin prepared by electrospinning technology. The contact angle diagram shows that the contact angle of the material is 143, showing obvious hydrophobicity. This hydrophobicity may be attributed to the changes in the chemical composition and surface morphology of the material during the electrospinning process. Hydrophobic electrospun materials have unique advantages in waterproofing and self-cleaning, and can avoid the effects caused by precipitation in forest and field scenes. For example, the contact angle of this experiment can effectively prevent the penetration of water and improve the waterproof performance of the material. In self-cleaning materials, the hydrophobic surface can make water droplets roll off quickly, taking away dust and pollutants on the surface, and keeping the surface of the material clean.

[0035] The diameter distribution of PHB nanofibers is shown in Figure 3 As shown. The diameter of PHB nanofibers is mainly distributed in 4.33±0.53μm. This distribution range shows that the patented technology can effectively control the fiber diameter when preparing PHB nanofibers, making them have a more concentrated size distribution. There is an obvious peak in the distribution diagram, and its corresponding diameter is 4.3μm. This shows that in the preparation process of this patent, the diameter of most PHB nanofibers is close to this value, reflecting the stability and repeatability of the process.

[0036] Example 2

[0037] From August to September 2024, the above-mentioned attractant core (PHB nanofiber of Example 1) was used in Qinyuan, Shanxi, and a bark beetle trap (TF-2 type, Hangzhou Pheromone Biotechnology Co., Ltd.) was used to lure red lipid beetles in the forest. The experiment lasted for 43 days.

[0038] 1) Hang 1-2 traps per acre;

[0039] 2) In the same small area (2-3 mu of insect population), place one set of PHB nanofiber lure and one set of control material lure as a treatment group, with 3 replicates. The control material is the trap bottle that comes with the trap product used, and 2.34g of pheromone 3-carene is added for control trapping. 2.34g of pheromone 3-carene is used in the preparation of the experimental group materials. The total amount of pheromone is the same as that of the control. A single PHB lure consists of a total amount (1200cm 2 ) An area of ​​5 cm x 5 cm was cut out for use, so each bait core in the experimental group contained about 0.05 g of pheromone (2.34÷1200 / 25=0.048).

[0040] 3) Starting from the fifth day after the traps were hung, the number of Dendroctonus eryngii trapped in all the traps was counted and recorded every five days. The data of the trapped Dendroctonus eryngii were compared and counted among the various materials.

[0041] The effect of using PHB nanofibers in the forest to attract red beetles is as follows: Figure 4As shown. Under the condition of using the same dose of pheromone, PHB nanofibers trapped a total of 39 red lip beetles during the experiment, which was significantly higher than the 7 in the control trapping bottle. At the same time, the PHB nanofibers carrying red lip beetle pheromones gradually released the active ingredients in the product in a stable and continuous manner over time. On the 43rd day after the end of the forest experiment, red lip beetles could still be stably trapped, and the sustained-release effect was significantly enhanced, reaching more than 40 days. This patented technical material avoids the waste and environmental risks caused by a one-time large-scale release, has good persistence and specificity in releasing active ingredients, meets the requirements of sustainable agricultural development, and provides a new solution for achieving green, environmentally friendly, and efficient agricultural production. It has broad market prospects and application value.

[0042] The linear regression statistical results between the number of Dendroctonus beetles trapped in this material and the average temperature of the day are as follows Figure 5 As shown. By adding paraffin wax to the material, it can achieve the intelligent effect of high-temperature release and low-temperature closure. The role of paraffin wax in the material is that when the temperature is high, the paraffin wax melts, so that the channels inside the material are opened, and the pheromone of the red lip beetle is released; when the temperature is low, the paraffin wax solidifies, closes the channels inside the material, and prevents the release of the pheromone of the red lip beetle. According to the experimental data statistics in the forest field, it was found that the average daily number of red lip beetles attracted by PHB nanofibers has a significant positive correlation with the daytime temperature (****, P<0.0001), indicating that the material of the present invention has obvious temperature response characteristics, and the intelligent capture effect of the electrospinning material is achieved by adding paraffin wax. The cost is low, the preparation method is simple, and it is easy to mass produce.

Claims

1. A method for preparing temperature-responsive electrospun nanofibers of Dendroctonus rubrum pheromone, characterized in that: The following steps are involved: A. Mix dichloromethane and paraffin to obtain solution A; B. Add polyhydroxybutyrate and Dendroctonus rubrum pheromone 3-carene into solution A, stir and dissolve to obtain solution B; C. Electrospin solution B to obtain temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone.

2. The preparation method according to claim 1, characterized in that: The specific steps are: A. Mix dichloromethane and paraffin in a mass ratio of 6:4 to obtain solution A; B. Add polyhydroxybutyrate and 3-carene to solution A at a mass volume ratio of 0.7 g::2.34 g:15 ml, stir and dissolve to obtain solution B; C. Electrospin solution B to obtain temperature-responsive electrospun nanofibers of Dendroctonus beetle pheromone.

3. The preparation method according to claim 1, characterized in that The step c is as follows: injecting solution B into a syringe pump, then turning on the power supply for electrostatic spinning, with a flow rate of 4 ml / h, adjusting the distance from the syringe needle to the receiving device to 10 cm, the voltage of the high-voltage power supply to 15 kV, the temperature of the receiving device to 75° C., and the drum speed to 500 r / min. After electrostatic spinning, a uniform white fiber film is collected on the hand-screen roller, and after tearing off the polyester fiber film, vacuum drying is performed at room temperature to obtain temperature-responsive electrospun nanofibers of the pheromone of Dendroctonus erythrorhizium.

4. A temperature-responsive electrospun nanofiber of Dendroctonus rubrum pheromone prepared according to the preparation method of claim 1, 2 or 3.

5. A bait for attracting Dendroctonus rubrum, characterized in that: The temperature-responsive electrospun nanofiber of Dendroctonus erythrorhizonii pheromone as claimed in claim 4 is used as the attractant.

6. The lure core according to claim 5, characterized in that: The size of the lure core is obtained by cutting the temperature-responsive electrospun nanofibers of the pheromone of Dendroctonus rubrum into lure chips of 2cm x 2cm to 5cm x 5cm.

7. A trap for Dendroctonus rubrum, characterized in that: Comprising the lure core described in claim 5 or 6.

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