Pheromone attractant for attracting bemisia tabaci

Abstract

The invention relates to a pheromone attractant for attracting bemisia tabaci. According to the pheromone attractant beta-myrcene, beta-myrcene and alpha-pinene, the trapping effect of the bemisia tabaci can be remarkably improved by soaking the blank lure, and the pheromone attractant has a relatively strong trapping effect on female bemisia tabaci and male bemisia tabaci and has the characteristics of long lasting period, greenness, safety and strong field applicability; the prevention and control requirements of bemisia tabaci pests in the field can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of pest control, and particularly relates to a pheromone attractant for luring whitefly and an application thereof. Background Art

[0002] Bemisia tabaci, belonging to the order Hemiptera, family Aleyrodidae, is widely distributed in more than 90 countries and regions and is one of the most economically destructive crop pests. Bemisia tabaci mainly harms ornamental plants, vegetables, beans, cotton and other crops. The direct harm to host plants is to suck the host plants through the mouth needle, causing the plants to weaken and dry up; the indirect harm is to spread plant viruses, causing serious viral disease outbreaks, causing very serious losses to fruit trees and food crops. In addition, Bemisia tabaci can easily develop resistance to many types of insecticides, including organophosphates, carbamates, pyrethroids, neonicotinoids, juvenile hormones and other insecticides. Therefore, the best way to reduce the damage caused by Bemisia tabaci is to control the number of insects by trapping and killing Bemisia tabaci in the early stage of the outbreak to reduce the damage.

[0003] At present, the main technical method for preventing and controlling whiteflies is yellow board trapping, which is based on the habit of whiteflies to move toward yellow, and the bright yellow color is used to lure whiteflies to achieve the effect of killing. Whiteflies mainly search for host plants through vision and smell, which is why yellow board trapping can play a good role in preventing and controlling whiteflies. However, yellow boards still have defects in actual use. In field environments or greenhouse environments, plants are densely planted, whiteflies' vision is severely obstructed, and the trapping area of ​​yellow boards is limited, so the control of whiteflies cannot reach an ideal state. Therefore, existing technical products have limitations in use.

[0004] Li Shu et al. also studied the behavioral selection of cryptic species of Bemisia tabaci to different plant volatile substances in "Behavioral Responses of MED Cryptic Species of Bemisia tabaci to 13 Plant Volatile Substances". They found that linalool, trans-2-hexenal and eucalyptol have significant attraction effects on female and male cryptic species of Bemisia tabaci, and cymene, myrcene, 3-carene, α-pinene and cis-3-hexene-1-ol have different degrees of attraction and avoidance to female and male Bemisia tabaci. However, the above studies will produce large variables due to different concentrations of volatile substances released by different plant varieties, plant health or damaged states. Therefore, it is necessary to develop a pheromone that can control Bemisia tabaci with stable performance in the field. Summary of the invention

[0005] Considering that plant-derived odor substances are often mixed, existing research has only focused on single odor substances without considering the odor of the plant itself. In order to overcome the shortcomings and deficiencies of the prior art, the present invention redesigned the experiment and discovered a new pheromone attractant for whiteflies.

[0006] In a first aspect, the present invention provides use of β-myrcene as a pheromone attractant for attracting Bemisia tabaci.

[0007] β-Myrcene, as the attractant component of whitefly pheromone, is a specific terpene substance. This substance is screened based on the biological characteristics of whitefly pests and the types and characteristics of their tropism stimulating factors. It has a specific attractant effect on whitefly pests and can induce whitefly adults to gather.

[0008] In some embodiments, the pheromone attractant consists of β-myrcene and a solvent.

[0009] In some embodiments, the pheromone attractant of the present invention can effectively attract whiteflies without containing other effective ingredients.

[0010] In a second aspect, the present invention provides use of a combination of β-myrcene and α-pinene as a pheromone attractant for attracting Bemisia tabaci.

[0011] During the experiment, it was found that when α-pinene was used alone, its attracting effect on whiteflies was not obvious. However, surprisingly, when α-pinene was combined with β-myrcene, the trapping efficiency for whiteflies was significantly improved.

[0012] In some embodiments, only by compounding the two effective ingredients of β-myrcene and α-pinene, the tendency of whiteflies can be significantly changed, thereby improving the trapping efficiency.

[0013] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is suitable for plants infested by whiteflies of the Solanaceae, Leguminosae, Cruciferae, Poaceae, Cucurbitaceae, Asteraceae or Malvaceae families.

[0014] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is used for tomato.

[0015] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is used for eggplant.

[0016] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is used for pepper.

[0017] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is used for tobacco.

[0018] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is used for cotton.

[0019] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the pheromone attractant is soaked in the attractant core having a slow-release effect.

[0020] In some embodiments, according to the use of the first aspect and the second aspect of the present invention, the attractant core is a sponge or a fiberboard.

[0021] In some embodiments, the pheromone attractant of the present invention can be used in conjunction with yellow boards to kill whiteflies, thereby more efficiently achieving the purpose of controlling target pests.

[0022] In some embodiments, the pheromone attractant of the present invention is in liquid form, and a blank attractant core can be soaked to attract male and female target whiteflies, and can be used in conjunction with a yellow board to further kill the whiteflies, thereby achieving the purpose of killing the whiteflies.

[0023] In a third aspect, the present invention provides a pheromone attractant for Bemisia tabaci, wherein the active ingredient of the pheromone attractant comprises β-myrcene at a concentration not exceeding 5000 ng / μL.

[0024] In some embodiments, the concentration of β-myrcene can be, for example, 5000 ng / μL, 4500 ng / μL, 4000 ng / μL, 3500 ng / μL, 3000 ng / μL, 2500 ng / μL, 2000 ng / μL, 1500 ng / μL, 1000 ng / μL, 500 ng / μL, 200 ng / μL, 100 ng / μL, 50 ng / μL, or 20 ng / μL.

[0025] The concentration of the active ingredient β-myrcene within the above range has a good trapping effect on whiteflies. If the concentration is too high, for example, exceeding 5000 ng / μL, the trapping effect is not obvious.

[0026] In some embodiments, the active ingredient of the pheromone attractant further includes α-pinene at a concentration not exceeding 2000 ng / μL.

[0027] Optionally, the β-myrcene concentration is 20-5000 ng / μL; Optionally, the β-myrcene concentration is 20-2000 ng / μL; In some embodiments, the concentration of α-pinene can be, for example, 2000 ng / μL, 1500 ng / μL, 1000 ng / μL, 500 ng / μL, 200 ng / μL, 100 ng / μL, 50 ng / μL or 20 ng / μL.

[0028] In some embodiments, the concentration ratio of β-myrcene to α-pinene is (1-10):1.

[0029] In some embodiments, the concentration ratio of β-myrcene to α-pinene is, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0030] The compounding of β-myrcene and α-pinene in the above ratio has a good attracting effect on whiteflies and can improve the trapping efficiency of whiteflies.

[0031] In some embodiments, the pheromone attractant is obtained by adding the active ingredient to a solvent and shaking and mixing the mixture. The solvent includes dichloromethane, dimethyl sulfoxide, isopropyl ketone, and the like.

[0032] The solvent has a good dissolving effect on the effective ingredient β-myrcene, and after soaking the filter element, it is beneficial for the effective ingredient to better exert its trapping effect.

[0033] In some embodiments, the solvent excludes paraffin and acetone.

[0034] In a fourth aspect, a product for controlling whitefly includes the above-mentioned information attractant and information attractant carrier; optionally, the carrier includes one or more of the following: a trap, a sticky trap; optionally, the carrier is a sticky yellow board, a funnel trap or a sucker.

[0035] A fifth aspect is a method for controlling whiteflies in a field or greenhouse, comprising placing the above-mentioned control product in a field or greenhouse to trap whiteflies; optionally, the amount of the control product is adjusted according to the number of whiteflies in the field, greenhouse or greenhouse.

[0036] The beneficial effects of the present invention are as follows:

[0037] According to the biological characteristics of whitefly pests, the present invention discovers the types and characteristics of its tropism stimulating factors, adopts a better luring method, and develops a pheromone lure with β-myrcene or a compound of β-myrcene and α-pinene as the effective component of the pheromone. The pheromone is made to reach a suitable concentration for luring by an organic solvent, the preparation steps are simple and suitable for field use, and the pheromone is slowly released by using a lure core. The pheromone lure of the present invention is simple to use, and the pheromone lure can be used to smear or soak the lure core. In addition, the pheromone lure of the present invention can be used in conjunction with a yellow board to more effectively lure and kill whitefly pests, and is safe, green, non-toxic and harmless.

[0038] The inventors have overcome the obstacles of the prior art and creatively proposed the use of β-myrcene as a pheromone attractant to attract whiteflies. The pheromone attractant of the present application can be applied to various climatic conditions. By soaking a blank attractant core with the pheromone attractant, the attracting effect of whiteflies can be improved. At the same time, it has a strong attracting effect on both female and male target whiteflies. It has the characteristics of long-lasting effect, green safety, and strong field applicability, and can meet the needs of trapping and controlling whitefly pests in the field. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Shown is the tropism of Bemisia tabaci (B. tabaci) towards tomato yellow leaf curl virus (TYLCV)-infected tomato plants.

[0040] (AI) Analysis of the tendency of whiteflies to TYLCV-infected tomato plants at different time points. (A) 12h; (B) 24h; (C) 36h; (D) 48h; (E) 60h; (F) 72h; (G) 84h; (H) 96h; (I) 108h. Data are the mean ± SD of 8 biological replicates, with at least 50 whiteflies in each replicate (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0041] Figure 2 Shown are the results of functional analysis of different volatiles in tomato plants infected with TYLCV.

[0042] (A) Schematic diagram of the free choice experiment; (BL) Differences in the tropism of whiteflies to different volatiles. (B) α-humulene; (C) α-pinene; (D) (+)-2-carene; (E) β-caryophyllene; (F) β-ocimene; (G) tetradecane; (H) α-phellandrene; (I) β-ionone; (J) 2-carene; (K) p-cymene; (L) β-myrcene. Data are the mean ± standard error of 8 biological replicates, with at least 50 whiteflies in each replicate (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0043] Figure 3 The figure shows the attraction of different concentrations of β-myrcene to Bemisia tabaci.

[0044] (A) Schematic diagram of the free choice experiment; (BE) The attraction of different concentrations of β-myrcene to whiteflies. (B) 2000 ng / μL; (C) 200 ng / μL; (D) 20 ng / μL; (E) 2 ng / μL. Data are the mean ± standard error of 8 biological replicates, with at least 50 whiteflies in each replicate (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0045] Figure 4 The figure shows the attraction of different concentrations of cymene to Bemisia tabaci.

[0046] (A) Schematic diagram of the free choice experiment; (BE) The attraction of different concentrations of paracymene to whiteflies. (B) 2000 ng / μL; (C) 200 ng / μL; (D) 20 ng / μL; (E) 2 ng / μL. Data are the mean ± standard error of 8 biological replicates, with at least 50 whiteflies in each replicate (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0047] Figure 5 Shown are the results of trapping Bemisia tabaci in the vegetable greenhouse of Shunyi Suihang Base.

[0048] Note: The number of whiteflies captured in the control (CH2Cl2) group and the β-myrcene group in the vegetable greenhouse (different numbers represent different vegetable greenhouses). The data are 10 biological replicates. The data are expressed as mean ± standard error (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0049] Figure 6 The attractiveness of β-myrcene to Bemisia tabaci on different host plants is shown.

[0050] Note: (A, C, E) Schematic diagram of the free-choice experiment of whiteflies; (B) The attraction of 2000ng / μL and 200ng / μL β-myrcene to whiteflies on cotton; (D) The attraction of 2000ng / μL and 200ng / μL β-myrcene to whiteflies on pepper; (F) The attraction of 2000ng / μL and 200ng / μL β-myrcene to whiteflies on tobacco. The data are from 8 biological replicates, with at least 50 whiteflies in each replicate, and the data are expressed as mean ± standard error (*, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0051] Figure 7 The results of the analysis of volatile components of four plants: tomato, cotton, pepper, and tobacco.

[0052] Figure 8 The results show that the combination of β-myrcene and odor volatiles has an attractive effect on Bemisia tabaci on pepper.

[0053] Note: (A) Schematic diagram of the free-choice experiment of whiteflies; (B) The attraction of β-myrcene and odor volatiles to whiteflies on pepper. The data are 8 biological replicates, with at least 50 whiteflies in each replicate, and the data are expressed as mean ± standard error (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0054] Fig. 9 The attraction of α-pinene to Bemisia tabaci on pepper is shown.

[0055] Note: (A) Schematic diagram of the free-choice experiment of whiteflies; (B) The attraction of α-pinene to whiteflies on pepper. The data are from 8 biological replicates, with at least 50 whiteflies in each replicate, and the data are expressed as mean ± standard error (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0056] Fig.10 Shown are the results of trapping Bemisia tabaci in pepper fields at Changping Baishan Base.

[0057] Note: The number of whiteflies captured in the pepper field by the control (CH2Cl2) group and the group mixed with β-myrcene and odor volatiles. (Indicates that only the combination of α-pinene and β-myrcene is attractive to whiteflies, and there is no statistical difference between the other mixed groups). The data are 10 biological replicates, and the data are expressed as mean ± standard error (*, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively).

[0058] Fig.11 Shown are the results of trapping Bemisia tabaci in the eggplant greenhouse at Changping Baishan Base.

[0059] Note: The number of whiteflies captured in the eggplant greenhouse by the control (CH2Cl2) group and the β-myrcene and α-pinene compound group. (Different numbers represent different eggplant greenhouses). The data are from 10 biological replicates and are expressed as mean ± standard error (*, *, *, ** represent P<0.05, P<0.01 and P<0.001, respectively).

[0060] Fig.12 Shown are the results of trapping Bemisia tabaci in the pepper greenhouse at Changping Baishan Base.

[0061] Note: The number of whiteflies captured in the control (CH2Cl2) group and the β-myrcene and α-pinene compound group in the pepper greenhouse. (Different numbers represent different pepper greenhouses). The data are 10 biological replicates, and the data are expressed as mean ± standard error (*, *, *, ** represent P < 0.05, P < 0.01 and P < 0.001, respectively) DETAILED DESCRIPTION

[0062] The present invention is further described below in conjunction with specific embodiments, which are only used to explain the present invention and are not to be construed as limiting the present invention. It will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and purposes of the present invention, and that the scope of the present invention is defined by the claims and their equivalents. The experimental methods for which specific conditions are not specified in the following embodiments are usually tested under conventional conditions or under conditions recommended by the manufacturer.

[0063] definition

[0064] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly used in the field to which the present invention belongs. For the purpose of interpreting this specification, the following definitions will apply, and where appropriate, terms used in the singular will also include the plural form, and vice versa.

[0065] Unless the context clearly dictates otherwise, the expressions "a", "an" and "an" as used herein include plural references. For example, reference to "a cell" includes a plurality of such cells and equivalents thereof known to those skilled in the art, and so forth.

[0066] As used herein, the term "about" refers to a range of ±20% of the value that follows. In some embodiments, the term "about" refers to a range of ±10% of the value that follows. In some embodiments, the term "about" refers to a range of ±5% of the value that follows.

[0067] Examples and drawings are provided below to help understand the present invention. However, it should be understood that these examples and drawings are only used to illustrate the present invention, but do not constitute any limitation. The actual protection scope of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention.

[0068] The chemical reagents used in the examples of this application are all commercially available.

[0069] Experimental example 1.

[0070] This experiment was conducted to study the tropism of Bemisia tabaci (B. tabaci) to tomatoes infected with Tomato Yellow Leaf Curl Virus (TYLCV). Insects mainly locate hosts through olfaction, and solid phase microextraction was used to identify the volatile components of tomatoes.

[0071] Take 2g of leaves from each healthy tomato plant and TYLCV-infected tomato plant, and take 4 plants each. After taking the leaves, immediately put them into a mortar with liquid nitrogen and grind them into powder. Then transfer the powdered leaves to a 15mL injection bottle, weigh 0.6g of NaCl and add it, and add 50μL of 2-nonanone with a concentration of 1025ng / μL. After adding the magnetic rotor, heat the injection bottle in water for 10 minutes at a temperature of 50℃, age the extraction head at 250℃ for 10 minutes, and then insert the extraction head into the injection bottle for 40 minutes. Immediately remove the extraction head and insert it into the GC-MS injection port, and start the injection procedure at the same time.

[0072] The gas chromatography and mass spectrometry conditions are as follows: Agilent's 30mHP-5MS column was used for GC-MS separation of volatile substances. The column length is 30m, the diameter is 0.25mm, and the film thickness is 0.25μm. Helium was used as the carrier gas, the flow rate was 1mL / min, the split ratio was 2:1, and the injection port temperature was 250℃. The column oven was kept at 40℃ for 5min, then heated to 120℃ at 2℃ / min, and finally heated to 290℃ at 10℃ / min, and kept at 290℃ for 29 minutes. The mass spectrometer scanned the mass range from 35m / z to 400m / z, and the scanning speed was 781u / s.

[0073] The analysis results of different volatiles are shown in Table 1.

[0074] Table 1. Analysis of different volatiles in TYLCV-infected tomatoes and healthy tomatoes

[0075]

[0076]

[0077] ab: Different shoulder marks indicate that there is a significant difference in the odor between the two, and the same shoulder marks indicate that there is no significant difference.

[0078] As shown in Table 1, the volatile components of infected tomatoes and healthy tomatoes were analyzed by solid phase microextraction technology, and 8 volatile odor substances with significant differences between infected tomatoes and healthy tomatoes were found. Among them, β-myrcene had the highest increase in TYLCV-infected tomato plants, and its content in infected tomatoes was significantly higher than that in healthy tomatoes, about 2 times. In addition, 3 odor substances (α-pinene, tetradecane, α-phellandrene) with no significant difference but high content in tomatoes were selected as the control group and put into Table 1 for subsequent odor substance screening experiments.

[0079] This study found that whiteflies showed significant tropism for TYLCV-infected tomatoes ( Figure 1 ).

[0080] Experimental Example 2. Free Selection Experiment of Different Volatile Substances

[0081] Based on the results of solid phase microextraction analysis of odor substances in TYLCV-infected tomato plants and healthy plants, a free-choice device was used to conduct a test on the tendency of Bemisia tabaci to different odor substances. Figure 2 As shown in the figure, among the 11 odorants, there is one odorant that whiteflies avoid, α-humulene ( Figure 2 B) and two odorants of whitefly attraction, β-myrcene and p-cymene ( Figure 2 L, K).

[0082] Bemisia whiteflies show significant tropism to TYLCV-infected tomato plants, so we selected two odor substances that are tropistic to Bemisia whiteflies for further study. Dissolve p-cymene and β-myrcene in dichloromethane, shake and mix, and prepare a series of concentrations. After applying different concentrations of p-cymene and β-myrcene (2000ng / μL, 200ng / μL, 20ng / μL, 2ng / μL) on healthy tomato plants, the results showed that Bemisia whiteflies were very sensitive to β-myrcene, and still had significant tropism when the concentration of β-myrcene was reduced to 20ng / μL ( Figure 3 BD), while the attraction of p-cymene to whiteflies was only shown at 2000ng / μL. When the concentration of p-cymene was reduced to 200ng / μL, whiteflies lost their attraction to p-cymene ( Figure 4 CE).

[0083] Therefore, the above experimental results indicate that β-myrcene is the main odorant that attracts whiteflies to TYLCV-infected tomato plants.

[0084] Experimental Example 3.

[0085] In order to verify the effect of β-myrcene, a field test was conducted. According to the formula in Table 2 below, β-myrcene was dissolved in a solvent and mixed by shaking.

[0086] Table 2. Formulations of Examples 1-3 and Comparative Examples 1-3

[0087]

[0088]

[0089] The trapping effects of the pheromone attractants of Examples 1-3 of the present application and Comparative Examples 1-3 were compared, and the experimental scheme and results are as follows.

[0090] 1. The pheromone attractant prepared in Example 1 was used as the pheromone attractant group, the solvent dichloromethane was used as the blank control group (CK), and the comparative examples 1-3 were used as the control groups. The attractant cores were sealed and soaked for 24 hours respectively, and then taken out for use.

[0091] Experimental location: Greenhouse of the Vegetable and Flower Research Institute of the Chinese Academy of Agricultural Sciences, Beijing

[0092] Time: September 6-7, 2022

[0093] Crop: Tomato

[0094] Target pest: Bemisia tabaci

[0095] Each group of soaked bait cores were hung together with yellow boards in an open space of 1-1.5m in the tomato shed. Twelve boards were hung in each shed (300㎡) with similar spacing between each location. A total of 1 shed was hung. The number of insects trapped by each yellow board was investigated on the second day. The results are shown in Table 3 below.

[0096] Table 3. Number of whiteflies trapped in different treatment groups

[0097] Treatment Group Number of trapped insects (mean) CK 205 Example 1 399 Comparative Example 1 174 Comparative Example 2 219 Comparative Example 3 245

[0098] As shown in Table 3, the number of whiteflies trapped by the pheromone lure in Example 1 was significantly higher than that in the CK group, and the attraction efficiency was increased by more than 94%. In the comparative examples 1-3, the attraction efficiency of the excessively high concentration of β-myrcene and other non-specific solvents was lower than that in Example 1.

[0099] 2. The pheromone attractant prepared in Example 2 was used as the pheromone attractant group, the solvent dimethyl sulfoxide was used as the blank control group (CK), and the comparative examples 1-3 were used as the control groups. The attractant cores were sealed and soaked for 24 hours respectively, and then taken out for use.

[0100] Experimental location: Tomato shed of Guxin Agriculture, Pinggu, Beijing

[0101] Time: September 13-14, 2022

[0102] Crop: Tomato

[0103] Target pest: Bemisia tabaci

[0104] The soaked bait cores of each group were hung together with yellow boards in the open space of 1-1.5m in the tomato shed. Twenty boards were hung in each shed (500㎡) with similar spacing between each location. A total of three sheds were hung. The number of insects trapped by each yellow board was investigated on the second day. The results are shown in Table 4 below.

[0105] Table 4. Number of whiteflies trapped in different treatment groups

[0106] Shed 1 Processing Group Number of trapped insects (mean) CK 166 Example 2 228 Comparative Example 1 139 Comparative Example 2 176 Comparative Example 3 148 Shed 2 Processing Group Number of trapped insects (mean) CK 116 Example 2 200 Comparative Example 1 89 Comparative Example 2 121 Comparative Example 3 112 Shed 3 Treatment Group Number of trapped insects (mean) CK 120 Example 2 253 Comparative Example 1 85 Comparative Example 2 128 Comparative Example 3 115

[0107] As shown in Table 4, the number of whiteflies trapped by the pheromone lure of Example 2 was significantly higher than that of the CK group, and the attraction efficiency was increased by at least 37%, and the attraction efficiency was increased by up to 110%. The actual number of trapped insects is related to the insect population base in each greenhouse, but the treatment group of Example 2 was significantly higher than the CK group and the comparative examples 1-3.

[0108] 3. The pheromone attractant prepared in Example 3 was used as the pheromone attractant group, the solvent isopropanol was used as the blank control group (CK), and the comparative examples 1-3 were used as the control groups. The attractant cores were sealed and soaked for 24 hours respectively, and then taken out for use.

[0109] Experimental location: Suihang Agricultural Base, Shunyi, Beijing

[0110] Time: September 19-20, 2022

[0111] Crop: Tomato

[0112] Target pest: Bemisia tabaci

[0113] The soaked bait cores of each group were hung together with yellow boards in the open space of 1-1.5m in the tomato shed. 40 boards were hung in each shed (1000㎡), and the spacing between each place was similar. A total of 3 sheds were hung. The number of insects attracted by each yellow board was investigated on the second day. The results are shown in Table 5 below.

[0114] Table 5. Number of whiteflies trapped in different treatment groups

[0115] Shed 1 Processing Group Number of trapped insects (mean) CK 34 Example 3 57 Comparative Example 1 16 Comparative Example 2 23 Comparative Example 3 35 Shed 2 Processing Group Number of trapped insects (mean) CK 35 Example 3 61 Comparative Example 1 23 Comparative Example 2 32 Comparative Example 3 41 Shed 3 Treatment Group Number of trapped insects (mean) CK 147 Example 3 212 Comparative Example 1 110 Comparative Example 2 156 Comparative Example 3 147

[0116] As can be seen from Table 5, the number of whiteflies trapped by the pheromone attractant in Example 3 was significantly higher than that in the CK group, and the attraction efficiency was increased by at least 44%, while the attraction efficiency increased the number of trapped insects by up to 75%. The actual number of trapped insects was related to the insect population base in each greenhouse, but the treatment group in Example 3 was significantly higher than the CK group and the comparison groups 1-3.

[0117] In summary, from the results of Experimental Example 3, the pheromone lures of Examples 1-3 have a significant attraction effect on whiteflies, and their trapping efficiency is significantly higher than that of the CK group and the comparative examples 1-3. In Comparative Example 1, the concentration of the active ingredient β-myrcene is too high, and the trapping effect is not obvious. In Comparative Examples 2-3, non-specific organic solvents such as paraffin oil and acetone are used, and the trapping effect of the active ingredients on whiteflies is poor after soaking the filter element.

[0118] Experimental Example 4.

[0119] To further verify the role of β-myrcene, this field experiment was conducted in the Diyuan Suihang Agricultural Base in Lisui Town, Shunyi District, Beijing. Three common host plants of whiteflies were selected (tomato, pepper, and eggplant, with the numbers corresponding to the plastic greenhouse room numbers of the base, and different numbers refer to different independent greenhouses). The greenhouse has a span of 8m, a bay of 4m, a height of 3m, a width of 30m, and a length of 100m. The tomato variety is cherry tomato, and the period is about to pull the vines; the pepper variety is line pepper, and the period is the fruiting period; the eggplant variety is round eggplant, and the period is the fruiting period.

[0120] 20 double-sided imported yellow sticky insect boards (Asiatic organisms, specifications of 20*30cm) were evenly hung in each 500 square meters of greenhouse area, with two yellow boards about 10m apart in each row, and each yellow board was about 10m away from the edge of the greenhouse. After each row was hung, one row was left empty, and all yellow boards were fixed at the same height for observation and statistics. Subsequently, a 2000ng / μL β-myrcene solution was prepared with dichloromethane as the solvent and added to the slow-release device (1mL for a single attractant core). Ten yellow boards (internal and external crosses) were selected and glued to the center of the slow-release device. After 24 hours, the distribution of whitefly adults on the yellow boards was counted to evaluate the attractant effect of β-myrcene.

[0121] The results of the field whitefly luring experiment showed that the tomato group (B1) lured an average of 383 whiteflies with β-myrcene, which was significantly higher than the control group's average of 212 whiteflies, and the luring efficiency was significantly increased by 80%. Similarly, the tomato group (B2) lured an average of 381 whiteflies with β-myrcene, which was significantly higher than the control group's average of 231 whiteflies, and the luring efficiency was significantly increased by 65%. However, in the pepper group (A2, A3) and eggplant group (C5, C6), the β-myrcene application had no significant luring effect ( Figure 5 ). This experimental study showed that exogenous β-myrcene was attractive to whiteflies in tomatoes, but was less attractive to whiteflies in peppers and eggplants.

[0122] Experimental Example 5. Construction of compound model of β-myrcene

[0123] In further field tests, we found that 2000ng / μL of β-myrcene could only attract tomato plants in greenhouses, and adding β-myrcene to tomatoes did change the tendency of whiteflies, so we speculated that there might be some substances in tomatoes that play an important role. We conducted further experiments on this.

[0124] Since there may be compounds in tomato that are complexed with β-myrcene, which may lead to changes in the tropism of whiteflies, three other host plants of whiteflies were selected: cotton, pepper, and tobacco. A free choice experiment with exogenous addition of β-myrcene was performed to determine whether there were compounds with β-myrcene in the plant.

[0125] In order to explore whether there are compounds of β-myrcene in cotton, pepper and tobacco, this study conducted a free choice experiment of whiteflies in a behavior box with β-myrcene applied to cotton, pepper and tobacco ( Figure 6 A, C, E). The results showed that adding 2000ng / μL of β-myrcene to cotton had a significant attraction to whiteflies, while adding 200ng / μL of β-myrcene did not attract whiteflies ( Figure 6 B). Adding 2000ng / μL and 200ng / μL of β-myrcene to pepper and tobacco did not produce additional attraction to whiteflies ( Figure 6 D, F).

[0126] The above experiments confirmed the presence of β-myrcene compounds in tomatoes and cotton, but not in peppers and tobacco.

[0127] Experimental Example 6. Determination of the compound of β-myrcene

[0128] Based on the complex existence model, solid phase microextraction method was used to identify the volatile components of tomato, cotton, pepper and tobacco based on GC-MS detection platform and Maiwei metabolic self-built database. 18 plants were taken from each plant, which needed to be healthy and of the same growth for cross sampling. Leaves of the same size were taken from every 3 plants to set up biological replicates, and 6 biological replicates were required for each plant. After removing the leaves, they were immediately put into liquid nitrogen for grinding and vortex mixing. About 500 mg (1 mL of liquid) of each sample was weighed into a 15 mL injection bottle, and saturated NaCl solution and 10 μL of 2-nonanone (concentration of 50 μg / mL, internal standard solution) were added respectively. Samples were extracted using fully automatic headspace solid phase microextraction HS-SPME. For GC-MS analysis.

[0129] HS-SPME extraction conditions: The extraction head was aged at 250°C for 5 min in the Fiber Conditioning Station before sampling. Under constant temperature of 60°C, the extraction head was shaken for 5 min, and the extraction head was inserted into the sample headspace bottle for headspace extraction for 15 min. The extraction was performed at 250°C for 5 min, and then GC-MS separation and identification were performed.

[0130] Gas chromatography conditions: GC-MS separation of volatile substances uses a DB-5MS capillary column from Agilent, USA, 30m long, 0.25mm in diameter, and 0.25μm in film thickness. High-purity helium (purity not less than 99.999%) is used as the carrier gas, with a constant flow rate of 1.2mL / min, non-split injection, an injection port temperature of 250°C, and a solvent delay of 3.5min. Program temperature rise: The column oven is kept at 40°C for 3.5min, then heated to 100°C at 10°C / min, then heated to 180°C at 7°C / min, and finally heated to 280°C at 25°C / min, and kept at 280°C for 5 minutes.

[0131] Gas phase mass spectrometry conditions: electron bombardment ion source, ion source temperature of 230°C, quadrupole temperature of 150°C, mass spectrometer interface temperature of 280°C, electron energy of 70eV, scanning mode of selected ion detection mode (SIM), qualitative and quantitative ion precise scanning.

[0132] The volatile components of four plants, namely tomato, cotton, pepper and tobacco, were analyzed by solid phase microextraction technology. Figure 7 As shown in A, there are 434 volatiles in tomato, 462 volatiles in cotton, 305 volatiles in pepper, and 313 volatiles in tobacco. Figure 7 As shown in B, 110 volatiles that exist in both cotton and tomato but not in pepper and tobacco were screened. These 110 volatiles were further compared with the main odor substances in tomatoes, and five substances were screened, namely β-myrcene, α-pinene, p-cymene, α-phellandrene, terpinolene, and α-terpinene.

[0133] In order to test the efficacy of the above-screened compound, an indoor insect behavior experiment was conducted to detect the changes in the tropism of whiteflies to the application of β-myrcene in pepper plants. Using dichloromethane as the solvent, 1mL of the mixture was prepared, with a β-myrcene concentration of 2000ng / μL and another odorant concentration of 500ng / μL. The experimental results showed that only the compound of β-myrcene and α-pinene could significantly change the tropism of whiteflies, while the compound of β-myrcene with the other four substances would not produce additional attraction to whiteflies ( Figure 8 ).

[0134] We then conducted a free choice experiment in which only α-pinene was added to peppers (1 mL of solution was prepared with dichloromethane as solvent, and the concentration of α-pinene was 500 ng / μL). This confirmed that the attraction was not α-pinene itself. Adding α-pinene to peppers did not change the tendency of whiteflies and did not produce additional attraction to whiteflies, which showed that α-pinene was a key compound of β-myrcene ( Fig. 9 ).

[0135] Experimental Example 7.

[0136] In order to further verify the attraction of the compound to whiteflies, we conducted a field whitefly attraction experiment to explore the attraction of the compound to whiteflies. Using dichloromethane as the solvent, 1 mL of the mixture was prepared, with a β-myrcene concentration of 2000 ng / μL and another odorant concentration of 500 ng / μL. In the pepper group of Changping Baishan Recycling Garden, the compound with α-pinene (A1) attracted an average of 521 whiteflies, which was significantly higher than the average of 240 whiteflies attracted by the control group, and the trapping efficiency was increased by 116.7%. The other four volatiles (para-cymene (A2), α-phellandrene (A3), terpinolene (A4), α-pinene (A5)) and β-myrcene had no additional attraction effect on whiteflies compared with the control group ( Fig.10 ). This indicates that only the combination of α-pinene and β-myrcene is attractive to whiteflies.

[0137] Experimental Example 8.

[0138] Field experiments were conducted to further determine the preference of Bemisia tabaci for the mixture of α-pinene and β-myrcene. Using dichloromethane as solvent, 1 mL of the mixture was prepared with a β-myrcene concentration of 2000 ng / μL and an α-pinene concentration of 500 ng / μL. Fig.11 As shown, in the eggplant greenhouse of Changping Baishan Circulation Park, the yellow board ( Fig.11 The red column on the left attracted an average of 310 whiteflies, which was significantly higher than that without adding β-myrcene ( Fig.11 The blue column on the left) trapped an average of 191 whiteflies, and the trapping efficiency was relatively increased by 62.3%. Yellow board ( Fig.11 The red column on the right attracted an average of 169 whiteflies, which was significantly higher than that without adding β-myrcene ( Fig.11 The blue column on the right side trapped an average of 111 whiteflies, and the trapping efficiency was relatively increased by 51.9%.

[0139] The results of the compounding of α-pinene and β-myrcene in the eggplant greenhouse showed that the compounding of α-pinene and β-myrcene would change the tropism of Bemisia tabaci and significantly improve the trapping efficiency of Bemisia tabaci.

[0140] Experimental Example 9.

[0141] Field experiments were conducted to further determine the preference of Bemisia tabaci for the mixture of α-pinene and β-myrcene. Using dichloromethane as solvent, 1 mL of the mixture was prepared with a β-myrcene concentration of 2000 ng / μL and an α-pinene concentration of 500 ng / μL. Fig.12 As shown, in the pepper greenhouse of Changping Baishan Circulation Park, the yellow board ( Fig.12 The red column on the left attracted an average of 313 whiteflies, which was significantly higher than that without adding β-myrcene ( Fig.12 The blue column on the left) trapped an average of 215 whiteflies, and the trapping efficiency was relatively increased by 45.6%. The yellow board ( Fig.12 The red column on the right attracted an average of 259 whiteflies, which was significantly higher than that without adding β-myrcene ( Fig.12 The blue column on the right side trapped an average of 178 whiteflies, and the trapping efficiency was relatively increased by 45.5%.

[0142] The results of the compounding of α-pinene and β-myrcene in the pepper greenhouse showed that the compounding of α-pinene and β-myrcene would change the tropism of Bemisia tabaci and significantly improve the trapping efficiency of Bemisia tabaci.

[0143] This study used a free choice experiment to add β-myrcene to four host plants of whitefly, namely tomato, cotton, pepper and tobacco, to construct a model for the existence of complex substances. Five possible complex substances were further screened based on model analysis by GC-MS. Free choice experiments indoors and greenhouse experiments on pepper and eggplant in the field revealed that α-pinene is the key complex compound for β-myrcene to function. The complex attractant composed of α-pinene and β-myrcene has a significant attractant effect on whiteflies both indoors and in the field.

[0144] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. Use of β-myrcene as a pheromone attractant to attract whiteflies.

2. Use of a combination of β-myrcene and α-pinene as a pheromone attractant to attract Bemisia tabaci.

3. The use according to claim 1 or 2, characterized in that: The pheromone attractant is suitable for plants of the Solanaceae, Leguminosae, Cruciferae, Gramineae, Cucurbitaceae, Compositae or Malvaceae. Optionally, the pheromone attractant is used for one or more of tomato, eggplant, pepper, tobacco and cotton.

4. The use according to claim 1 or 2, characterized in that: The pheromone attractant is soaked in a slow-release attractant core, and optionally, the attractant core is a sponge or a fiberboard.

5. A pheromone attractant for Bemisia tabaci, characterized in that: The active ingredient of the pheromone attractant includes β-myrcene at a concentration not exceeding 5000 ng / μL; optionally, the β-myrcene concentration is 20-5000 ng / μL; optionally, the β-myrcene concentration is 20-2000 ng / μL.

6. The pheromone attractant according to claim 5, characterized in that: The active ingredient of the pheromone attractant also includes α-pinene at a concentration not exceeding 2000 ng / μL. Optionally, the concentration ratio of β-myrcene to α-pinene is (1-10):

1.

7. A pheromone attractant for Bemisia tabaci, characterized in that: The active ingredients of the pheromone attractant include α-humulene with a concentration exceeding 200 ng / μL or p-cymene with a concentration exceeding 200 ng / μL.

8. The pheromone attractant according to any one of claims 5 to 7, characterized in that: The pheromone attractant is obtained by adding the active ingredient into a solvent and shaking and mixing it, wherein the solvent includes dichloromethane, dimethyl sulfoxide or isopropyl ketone.

9. A product for controlling Bemisia tabaci, characterized in that: The product includes the information attractant and information attractant carrier described in any one of claims 5-7; optionally, the carrier includes one or more of the following: a trap, a sticky trap; optionally, the carrier is a sticky yellow board, a funnel trap or a sucker.

10. A method for controlling whitefly in a field or greenhouse, characterized in that: The control product of claim 9 is placed in a field or greenhouse to trap whiteflies; optionally, the amount of the control product is adjusted according to the number of whiteflies in the field, greenhouse or greenhouse.

Images