Attractant for trapping aleurocanthus spiniferus black bees and application of attractant

Abstract

The invention provides an attractant for trapping aleurocanthus spiniferus black bees and application of the attractant. The aleurocanthus spiniferus piercing and sucking induced tea tree release mutualism alpha-farnesene is separated and identified. The method comprises the following steps of: preparing a normal hexane solution with the concentration of 50 to 70 mg / mL, loading 0.75 to 1.25 ml of the normal hexane solution on a small section of wool felt strip, dropwise adding 1 mg of 2, 6-di-tert-butyl-4-methylphenol serving as a stabilizer, and sealing by using a plastic film with the thickness of 100 mu m, so as to prepare a lure core. The nymph period of the first generation, the second generation, the third generation and the fourth generation of the aleyrodid in the Zhejiang Anhui Su tea area is from middle April to late June, from late June to early August, from middle August to middle October and from middle October to late March of the next year. 13-17 alpha-farnesene lure cores are tied to the tea cluster environment where the aleyrodids severely occur in April, under June, in August and in October, the aleyrodids are trapped and guided to search for the aleyrodids, the parasitism rate can be increased by 2-3 times, and occurrence of the aleyrodids can be effectively controlled continuously for two years.

Description

Technical Field

[0001] The invention belongs to the field of plant protection and relates to an attractant for attracting spiny whitefly black bees and application thereof. Background Art

[0002] The black-spined whitefly Aleurocanthus spiniferus (Quaintance) is an important pest in tea gardens. From the early 1960s to the early 1990s, it broke out intermittently in tea-growing areas in the middle and lower reaches of the Yangtze River, southern China, and Hainan every 10 years or so. From 2005 to 2010, it occurred seriously in the tea-growing areas of Zhejiang, Anhui, and Jiangsu. Since 2020, it has continued to occur seriously in the tea-growing areas of Zhejiang, Anhui, and southern Jiangsu. The black-spined whitefly has four generations a year in the tea-growing areas of Zhejiang, Anhui, and Jiangsu. The nymphs and pupae live on the back of the lower leaves of the tea bushes. The adults like to gather on the tea branches in the morning and evening to mate, lay eggs, and suck the buds and leaves. The nymphs and adults excrete a large amount of "honeydew" that falls on the leaves below, breeding sooty bacteria and inducing the spread of tea sooty disease, causing the tea garden to become pitch black. Mid-April to late June, late June to early August, mid-August to mid-October, and mid-October to late March of the following year are the periods when the 1st, 2nd, 3rd, and 4th generations of blackspiny whitefly nymphs occur in the tea-growing areas of Zhejiang, Jiangsu, and Anhui.

[0003] Whenever blackthorn whiteflies occur seriously, the usual control method is to spray the whiteflies on the back of the leaves in the middle and lower layers of the tea bushes with high doses of pesticides multiple times. As the whiteflies are killed, a large number of natural enemy insects, spiders and neutral insects hiding in the middle and lower layers of the tea bushes are also killed. This vicious cycle continues.

[0004] Amitus hesperidum Silvertri is the main parasitic wasp of black spiny whitefly. In tea gardens, the larvae overwinter in the host black spiny whitefly. The overwintering generation of adults begins in early to mid-April, peaks in mid-to-late May, and ends in mid-June. The first generation of adults begins in early June, peaks in late June to mid-July, and ends in late July. The second generation of adults begins in mid-August, peaks in late August to mid-September, and ends in late September. The third generation of adults begins in mid-October, peaks in early November to mid-November. Its peak period in tea gardens is basically the same as that of black spiny whitefly nymphs. Each female bee can lay 70-95 eggs, with an average of 84 eggs. Use 10% honey water to feed newly emerged female and male bees, with an average lifespan of 6 days. Its highest parasitism rate in local tea bushes is 60%-95%, but this situation is rare. Normally, the black wasp cannot effectively control the black wasp population. According to a report in 1974, more than 700 bags of this species were collected twice in Chongqing Beipei Citrus Orchard in May and June 1974 and placed in the citrus orchard. It is estimated that 60,000 to 100,000 parasitic wasps emerged. After the parasitic wasps reproduced two generations, an investigation on October 15 found that the parasitism rate in different citrus orchards increased to varying degrees after the bees were released, with an increase of 3.81% to 40.51%.

[0005] There have been no reports of releasing bees in tea gardens, and the workload and cost of releasing bees are huge, which is impossible to achieve in the current production process. However, the tea garden environment is closed and stable, with abundant black bee resources of whiteflies. Attractants can be used to gather and guide them to find the host black whiteflies, increase the parasitism rate, and strengthen the potential of natural control. Long-term trapping to maintain its population will continue to suppress black whiteflies. Summary of the invention

[0006] The invention provides an attractant for attracting black wasps of spiny whiteflies and its application, and aims to utilize α-farnesene, a mutualist molecule emitted by whiteflies to harm tea trees. α-farnesene is made into an attractant. The attractant is carried on a small section of wool felt to make an attractant core, and the black wasp nymphs of spiny whiteflies occur in mid-April, late June, mid-August and mid-October, and the attractant core is tied to tea bushes. The attractant attracts and attracts black wasps of spiny whiteflies to search for and parasitize the first, second, third and overwintering generations of black wasp nymphs and pupae, and increases the parasitism rate by 2-3 times. Repeated application for a long period of 2 consecutive years can effectively control the serious occurrence of black wasp nymphs.

[0007] This is accomplished by following these steps:

[0008] The invention first discloses an attractant for attracting spiny whitefly black wasps, which contains active insect semiochemical α-farnesene, and uses a solvent to prepare α-farnesene into a 50-70 mg / ml solution as a spiny whitefly black wasp attractant. The invention uses α-farnesene to attract spiny whitefly black wasps and increase the parasitism rate of spiny whitefly black wasps on black spiny whiteflies.

[0009] Furthermore, the present invention uses α-farnesene induced by the black whitefly sucking to release tea trees as a mutualist, and indoor and field bioassays confirm that it significantly attracts the black whitefly. Therefore, α-farnesene is prepared into a 50-70 mg / ml n-hexane solution as a whitefly black wasp attractant.

[0010] According to a preferred embodiment of the present invention, the present invention also provides a lure core based on the attractant, wherein the attractant is loaded on a wool felt strip (length 4cm×width 2cm×thickness 0.5cm) and sealed with a 100μl plastic film. The content of α-farnesene on each lure core is 50-70mg. Preferably, the content of α-farnesene in each lure core prepared with the attractant is 60mg.

[0011] The preferred solvent is n-hexane, and the volume dosage of n-hexane on each lure is 1.0 mL / lure.

[0012] Preferably, after the attractant is loaded on each lure core, 1 mg of 2,6-di-tert-butyl-4-methylphenol (BHT) is loaded as a stabilizer.

[0013] The present invention also discloses a method for using the attractant to lure black bees to control black bees, an important pest in tea gardens, which is achieved by the following steps:

[0014] 1) Dissolve α-farnesene in n-hexane and prepare an attractant at a dosage of 50-70 mg / ml. The loading amount on each attractant core is 50-70 mg.

[0015] 2) The attractant is loaded on a wool felt strip (4cm×1cm×0.5cm) to make a lure core. The total content of α-farnesene on each lure core is 50-70mg. It is sealed with a 100μm plastic film and tied to the tea bushes in the tea garden.

[0016] 3) The distance between the insect attracting boards of the attracting core is 8m-12m.

[0017] 4) In mid-April, late June, mid-August and mid-October, when the 1st, 2nd, 3rd and 4th generation black spiny whitefly nymphs occur, place the lure in the middle layer of tea bushes in the tea garden to attract black wasps to search for and parasitize black spiny whitefly nymphs and pupae. Replace the lure every 60 days. Repeating this for 2 years can suppress the occurrence of black spiny whiteflies.

[0018] Compared with the prior art: (1) the present invention prepares tea tree mutualist α-farnesene as an attractant, drips it on a wool felt strip of 4 cm long × 2 cm wide × 0.5 cm thick, then drips an antioxidant (2,6-di-tert-butyl-4-methylphenol), and seals it with a plastic film to form an α-farnesene attractant core; the attractant core is attached to the tea branches in the middle layer of the tea bush to attract and guide the black whiteflies parasitized by the black whiteflies in the tea garden environment; the attractant core is easy to install, with a distance of 8m-12m between each other; it is highly efficient and saves labor and time. It will not cause pesticide pollution. (2) Blackthorn whitefly is an important pest in the tea-growing areas of Zhejiang, Anhui, Jiangsu and China. Its generations overlap, and nymphs and pupae account for nearly 90% of the total insect population. They live in tea bushes and on the back of lower leaves, sucking sap and excreting "honeydew" to induce the spread of tea sooty disease, causing the tea bushes to become dark, making chemical control difficult. The use of attractants can attract black wasps, important natural enemies of tea gardens, and guide them to search for hosts, significantly increasing the parasitism rate of blackthorn whiteflies. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the total ion current chromatogram of volatiles from CK tea tree.

[0020] Figure 2 This is the total ion current chromatogram of volatiles in tea trees damaged by whiteflies.

[0021] Figure 3 This is the total ion current chromatogram of volatiles from neighboring tea trees.

[0022] Figure 4 Schematic diagram of the four-arm olfactometer for measuring α-farnesene-attracted and retained behaviors of P. tabaci. DETAILED DESCRIPTION

[0023] Example 1 Isolation and Identification of Volatiles Released from Tea Trees Induced by Blackthorn Whitefly Piercing and Sucking

[0024] 1 Experimental design

[0025] On April 6, 2022, in the experimental tea garden of China University of Metrology, three healthy pots of Fuzao No. 2 were selected, all of which were 13 years old and had similar tree postures and vigor. Two pots were put together, and about 500 one-day-old black spiny whiteflies were introduced into one pot, covered with a 40-mesh screen to prevent escape, and the screen was removed only after the adult stage passed, as "whiteflies harming tea trees"; the other pot was not inoculated with insects, as "neighboring tea trees". The third pot was placed 20m apart, as CK.

[0026] On August 22, when the third generation of whiteflies was at its peak, 25 g of mature leaves were cut from each tea plant. The headspace dynamic adsorption method of Niu et al. (2022) (Niu Y Q, Han SJ, Wu ZH, Pan C, Wang MX, Tang YY, Zhang QH, Tan GJ, Han B. 2022. Apush-pull strategy for controlling the tea green leafhopper (Empoasca flavescens F.) using semiochemicals from Tagetes erecta and Flemingia macrophylla. Pest Management Science, 78, 2161–2172) was used. Place 25g of mature leaves from each cylinder into a cylindrical glass container with an air inlet and an air outlet. Let clean air flow in from the air inlet at a flow rate of 100ml / min. Connect the air outlet to a 150mg Super Q adsorption column, an air pump, and a flow meter. Pump air so that the air flow at the air inlet is slightly greater than that at the air outlet to prevent unpurified air from the external environment from entering the cylindrical glass container. After 24 hours of adsorption, remove the Super Q adsorption column, elute with 600μL of dichloromethane, and add 20μL of 10 -4 g / mL ethyl decanoate was used as the internal standard, which was slowly purged and concentrated to about 20 μL under a high-purity nitrogen flow, and 1 μL was aspirated and injected into GC-MS for detection.

[0027] The GC-MS instrument was manufactured by Agilent, model: gas chromatograph Agilent GC6890A coupled detector MSD6975. It was equipped with a HP-5MS quartz capillary column, length 30.0m×wall thickness 250μm×diameter 0.25μm. Qualitative analysis was based on: ① comparison of the retention time of the sample components with the retention time of the standard compound; ② comparison of the mass spectrum of the sample components with the mass spectrum of the compounds in the NIST11.L spectral library carried by the GC-MS instrument; ③ reference check of relevant literature. Relative quantification of sample components: relative quantification based on the ratio of the peak area of ​​the sample components to the peak area of ​​the internal standard. The test was repeated 4 times.

[0028] 2 Test results

[0029] 2.1 Significant changes in the composition and relative content of tea plant volatiles induced by the sucking damage of black spiny whiteflies

[0030] like Figure 1 As shown in the figure, it is the total ion current chromatogram of volatiles in healthy CK tea leaves. The number and content of volatile compounds measured are very small, which means that the types and content of volatiles released by healthy tea trees are very small. Figure 2 As shown in the figure, the total ion current chromatogram of volatiles in tea trees damaged by whiteflies shows a significant increase in the number and content of volatile compounds, especially the large increase in the content of α-farnesene, the increase in the number of volatiles, and the change in the ratio between them. Figure 3 As shown, it is the total ion current chromatogram of volatiles of neighboring tea trees. Its volatile compound fingerprint is similar to the volatile fingerprint of tea trees infested with whiteflies, and the content of α-farnesene is also significantly increased.

[0031] Figure 1-Figure 3 The names and contents of the compounds corresponding to the serial numbers of the volatile components of the CK tea trees, whitefly-infested tea trees, and neighboring tea trees are shown in Table 1.

[0032] Table 1 Qualitative and quantitative analysis of volatiles in CK tea trees, whitefly-infested tea trees and neighboring tea trees

[0033]

[0034]

[0035] 2.2 Black spiny whitefly induced tea trees and neighboring tea trees to release a large amount of α-farnesene

[0036] The piercing and sucking of black spiny whiteflies not only directly induces the damaged tea trees to activate their defense system, but also releases a large amount of α-farnesene ( Figure 2 ), and indirectly induced the neighboring tea trees to release rich α-farnesene ( Figure 3). This is because individual plants "talk" to each other through signal molecules (volatile compounds). The damaged tea trees warn the healthy tea trees next door, and the neighboring tea trees take defensive measures and release α-farnesene to defend against pests. α-Farnesene is the tea tree mutualist, which is used to attract the natural enemy of the black whitefly, the black whitefly wasp (see Example 2). Example 2 Indoor behavior measurement of α-farnesene strongly attracting the black whitefly wasp

[0037] 1 Experimental design

[0038] 1.1 Flavor Source

[0039] α-farnesene from the volatiles of tea trees damaged by whiteflies in Table 1 was selected as the flavor source, and the corresponding synthetic product was purchased from Sigma Company with a purity of ≥98.0%. -4 g / ml n-hexane solution. n-hexane was used as CK in the experiment.

[0040] 1.2 Test insects

[0041] From early April to late June 2023, branches and leaves carrying a large number of overwintering black spiny whitefly pupae were collected from tea gardens in the suburbs of Hangzhou, and hydroponically cultivated in a greenhouse, covered with a 60-mesh net to prevent the escape of the whitefly black bees (the whitefly black bees drill a hole from the back of the whitefly pupa, emerge, and fly out). The one-day-old whitefly black bees that emerged were collected and fed with 10% honey water, and allowed to mate freely. The test insects were both male and female, and all fasted for 15 minutes before the experiment.

[0042] 1.3 Four-arm olfactometer and its measurement procedure

[0043] like Figure 4 The four-arm olfactometer is made of colorless organic glass and connected to four hollow glass arms. The side length is 10cm, the height of the test chamber is 1.5cm, and it is divided into the central "a" area and four taste areas. The "a" area is a mixed area of ​​the four taste areas, with a diameter of 1cm; the remaining areas are divided into four taste areas according to the glass arms connected to them. Two of the opposing arms are closed. For the remaining two opposing arms, each arm is connected in turn to the taste source bottle (or CK bottle), humidification bottle, activated carbon filter bottle and flowmeter. The components are connected with Teflon glass tubes. During the test, air is drawn from the top opening of the "a" area in the center of the olfactometer, and the air flow rate of each arm is adjusted to 100ml / min.

[0044] Before the experiment and after each day of the experiment, the glass part was cleaned with potassium dichromate solution, rinsed with clean water and ultrapure water, and then dried for use. The activated carbon was taken out from the filter bottle, activated by blowing air at 100℃ for 4 hours, and stored after cooling for use. The ultrapure water in the humidification bottle was replaced. Before the experiment, the four-wall olfactometer was cleaned with clean water, rinsed with ultrapure water, and then rinsed with 75% ethanol, and dried in clean air. During the experiment, each time a parasitic wasp was tested, the inside and outside were wiped with a cotton ball dipped in 75% ethanol, and then dried before continuing.

[0045] The olfactometer system was placed in a glass chamber with a length of 1m × width of 1m × height of 2m in the greenhouse, and the top of the chamber was connected to the greenhouse. During the experiment, the glass chamber was surrounded by black cloth, and a 15W fluorescent lamp was used on the top to provide a diffuse light source. An air pump was used to pump air out from the bottom of the chamber. It was rotated 90° every 5 minutes to avoid the direction preference of the whitefly black wasp during the bioassay.

[0046] Pipette 10 μl 10 -4 10 μl of n-hexane was placed on a 3 cm long and 1 cm wide filter paper strip. When the n-hexane evaporated, the filter paper strip was inserted into the odor source bottle as the odor source. At the same time, 10 μl of n-hexane was absorbed on a 3 cm long and 1 cm wide filter paper strip. When the n-hexane evaporated, the filter paper strip was inserted into the CK bottle as the CK odor. A parasitic bee was introduced from the opening at the top of the "a" area, the lid was closed, and the air was continued to be pumped. First, let the parasitic bee get familiar with the environment inside the olfactometer for 2 minutes; in the next 10 minutes, the residence time of the bee in the odor source area and the CK area was recorded by a computer program. The same experiment was repeated 20 times.

[0047] The test time is 8:30-17:30, the temperature is 26±1℃, and the relative humidity is 70±5%.

[0048] 1.4 Statistical analysis

[0049] A t-test was performed to compare the differences between the 20 residence times of the 20 bees in the odor source area and the 20 residence times in the CK area.

[0050] 2 Test results

[0051] The retention time of 20 Aleurotus eryngii black bees in the odor source area and CK area was 8.21±0.51min and 1.79±0.51min respectively. The t-test showed that the difference between the two was significant, that is, α-farnesene significantly induced the bees to stay in the odor source area to search (Table 2).

[0052] Table 2 The residence time (min) of 20 whitefly black wasps in the odor source area and CK area and their differences

[0053]

[0054] Example 3 Field test of α-farnesene strongly attracting whitefly black bees

[0055] 1 Experimental design

[0056] In Zhejiang tea-growing areas, the first, second, third, and fourth generations of black spiny whitefly nymphs occur from mid-April to late June, late June to early August, mid-August to mid-October, and mid-October to late March of the following year. The black wasp of the spiny whitefly mainly parasitizes its nymphs and also parasitizes its pupae. From April 11 to 15, June 21 to 25, August 11 to 15, and October 11 to 15, 2023, an organic tea garden with relatively serious whitefly infestations in the mountainous area of ​​Songyang County in southern Zhejiang was selected. Ten 25cm×20cm bud green sticky boards were placed, and a small bottle was attached to the center of each board. The small bottle contained 10ml 10 -2 g / ml α-farnesene n-hexane solution, the vial top is open, the diameter is 0.5mm, and α-farnesene is slowly released. Preliminary experiments show that each 1ml can be released for 24 hours. At the same time, 10 25cm×20cm bud green sticky boards are placed, and a vial is attached to the center of each board. The vial contains 10ml of n-hexane, the vial top is open, and the diameter is 0.5mm. These 20 boards are randomly placed in the tea garden, with a distance of 20m between each other.

[0057] After each 5-day trapping, the number of whitefly black wasps on each board was counted. A t-test was performed on the difference in the number of whitefly black wasps on the α-farnesene board and the CK board during the same trapping period.

[0058] 2 Test results

[0059] Each experimental period was 5 days. The numbers of whitefly black bees trapped on 10 α-farnesene plates and 10 CK plates were shown in Table 3. The differences between the two plates were significant, which means that α-farnesene significantly attracted whitefly black bees to the bud green insect trap plates.

[0060] Table 3 The number of Aleuronectinellae trapped by α-farnesene boards and CK boards and their differences during the four trapping trials

[0061]

[0062]

[0063] Example 4 α-Farnesene significantly increases the parasitism rate of the black bee to the black whitefly in the tea garden (I)

[0064] 1 Experimental design

[0065] Mid-April to late June, late June to early August, mid-August to mid-October, and mid-October to late March of the following year are also the first, second, third, and fourth generation black spiny whitefly nymphs in Anhui tea areas. Black whitefly black wasps mainly parasitize their nymphs and sometimes also parasitize pupae. On April 11, a 20-mu organic tea garden in Jingting Mountain, Anhui Province, which had not been sprayed with pesticides for 20 years, was selected. Black spiny whiteflies re-emerged over the years. It was divided into 10 plots, each with an area of ​​1 mu, and the plots were 20 meters apart. Five plots were randomly selected as α-farnesene bait core areas, and 15 bait cores were placed in the middle layer of the tea bushes in each plot; each bait core contained 60 mg of α-farnesene, 200 μl of n-hexane, and 1 mg of 2,6-di-tert-butyl-4-methylphenol (BHT) as a stabilizer, and was carried on a wool felt strip of 4 cm long × 2 cm wide × 0.5 cm thick, and sealed with plastic film. In the remaining 5 plots, 15 CK bait cores were placed in the middle layer of the tea bushes in each plot, and each CK bait core only contained 1 mg of BHT and 200 μl of n-hexane. The agricultural activities of these 10 plots were the same.

[0066] The bait cores were replaced in each plot on June 11 and August 11. From October 11 to 15, samples were taken in each plot to investigate the parasitism rate of black spiny whiteflies. In each plot, the "five-point sampling method" was used, and each sampling point was a 10-m long tea row. About 400 black spiny whitefly pupae were investigated, and the number of pupae that were parasitized and left with "small round holes" on their backs was recorded to calculate the parasitism rate (Table 4).

[0067] 2 Test results

[0068] From October 11 to 15, 2023, the density of black whiteflies in the CK area was still high, but no pesticides were applied for many years, and the population density of black bees was also large. The natural parasitism rates of the five CK plots were 4.8±0.6%, 4.3±0.6%, 4.2±0.4%, 4.3±0.6% and 3.9±0.7% (Table 4). The continuous use of α-farnesene trap cores to release α-farnesene attracted a large number of black bees, and the parasitism rate was significantly increased. The parasitism rates of the five α-farnesene plots were 15.8±0.8%, 14.8±1.0%, 13.9±0.5%, 12.6±1.4% and 14.7±0.8% (Table 4). The "grouped data t-test analysis" of these two groups of data showed that the difference reached a significant level (t=20.4246, P<0.05). That is, α-farnesene strongly attracted the bee and significantly increased the parasitism rate.

[0069] Table 4 Parasitism rate of black bees on black whiteflies in α-farnesene and CK areas (Jingtingshan Tea Farm, Anhui Province, October 2023)

[0070]

[0071]

[0072] Example 5 α-Farnesene significantly enhances the control effect of the black bee on the black bee in the tea garden (II)

[0073] 1 Experimental design

[0074] In 2024, the same experiment as in Example 4 was repeated in the 20-mu organic tea garden of Jingtingshan Tea Farm in Anhui Province. The bait was placed on April 11, and replaced on June 11 and August 11. The parasitism rate of each plot was investigated from September 8 to 11.

[0075] 2 Test results

[0076] The survey found that the density of black spiny whiteflies decreased significantly compared with 2023. Although each sample point was still 10m long tea row, only about 150 pupae were surveyed.

[0077] From September 8 to 11, 2024, the density of black spiny whiteflies in the CK area and α-farnesene area was significantly lower than that in 2023. The population density of black bees of spiny whiteflies increased, and the natural parasitism rates of the five CK plots were 8.6±0.8%, 6.6±0.5%, 8.4±0.4%, 8.9±0.4% and 8.6±0.4% respectively (Table 5). The parasitism rate in the α-farnesene area was significantly increased, and the parasitism rates of the five α-farnesene plots were 20.4±1.9%, 21.8±1.6%, 21.0±1.1%, 21.1±0.9% and 21.4±0.8% respectively (Table 5). The two sets of data were subjected to "grouped data t-test analysis" and found that the difference reached a significant level (t=21.7028, P<0.05). The sustained release of α-farnesene significantly increased the parasitism rate.

[0078] Table 5 Parasitism rate of black bees on black whiteflies in α-farnesene and CK areas (Jingtingshan Tea Farm, Anhui Province, September 2024)

[0079]

[0080]

[0081] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An attractant for attracting whitefly black wasps, characterized in that: The invention contains active insect semiochemical α-farnesene, and the α-farnesene is prepared into a 50-70 mg / ml solution by using a solvent as an attractant for whiteflies and black bees.

2. The attractant for attracting whitefly black wasps according to claim 1, characterized in that The solvent is n-hexane.

3. A whitefly and black bee attractant core based on the attractant according to claim 1, characterized in that: The attractant is placed on a wool felt strip and sealed with a plastic film to prepare an attractant core. The content of α-farnesene in each attractant core is 50-70 mg.

4. A method for increasing the parasitism rate of black wasps on black whiteflies in tea gardens based on the attractant according to claim 1, characterized in that: This is accomplished by following these steps: 1) α-farnesene is prepared into a whitefly and black wasp attractant with n-hexane; 2) The attractant is placed on a small piece of wool felt strip and sealed with a plastic film to make a lure core; the content of α-farnesene in each lure core is 50-70 mg; the lure core is attached to the middle branches and leaves of the tea bushes in the tea garden where the black spiny whitefly is seriously infested; there are 13-17 lure cores per acre, and the distance between the lure cores is 8m-12m.

5. The method according to claim 4, characterized in that After α-farnesene was loaded on each lure core, 1 mg of 2,6-di-tert-butyl-4-methylphenol (BHT) was loaded as a stabilizer.

6. The method according to claim 4, characterized in that In the step 2), the lure cores are placed in the tea garden in mid-April, late June, mid-August and mid-October, and the lure cores are replaced every two months.

7. The method according to claim 4, wherein the bait core is placed in the tea garden for 2 consecutive years or more, which can effectively control the occurrence of black spiny whitefly disasters.

8. Use of α-farnesene in preparing a preparation for controlling black spiny whitefly, wherein the preparation for controlling black spiny whitefly is a natural enemy attractant of black spiny whitefly, and the natural enemy of black spiny whitefly is black bee of black spiny whitefly.

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