A composite sex attractant for gray tea geometrid and its application

Abstract

The present invention provides a composite sex attractant for gray tea geometre and its application, belonging to the field of plant protection. The present invention dissolves linalool, trans-2-hexenal, cis-3-hexene-1-ol, hexanol, phenylethyl alcohol, and 6-methyl-5-hepten-2-one, which are volatile compounds derived from tea trees, with two main sex pheromone compounds of gray tea geometre, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene, in a solvent in a mass ratio of 2-4:2-4:2-4:2-4:2-4:2-4:2-4:0.4-1.0:0.6-1.2 to form a composite sex attractant. The composite sex attractant is placed on a wool felt strip and sealed with a plastic film to form a lure core. The lure core is attached to a khaki insect trap plate, which is fixed to a tea garden. The composite sex attractant of the present invention can kill some female adults and a large number of male adults of the gray tea geometrid that are pregnant but have not yet laid eggs, thereby reducing the probability of mating, significantly reducing the number of eggs and larvae of the next generation, and reducing the damage to tea trees caused by the gray tea geometrid larvae.

Description

Technical Field

[0001] The invention belongs to the field of plant protection and relates to a composite sex attractant for gray tea geometrid and application thereof. Background Art

[0002] The gray tea looper, Ectropis grisescens, is one of the most serious pests in my country's tea gardens. Distributed throughout major tea-growing areas, it is particularly severe in East China. Six to seven generations occur annually, with larvae reaching five to seven instars. These larvae chew on the tender branches and leaves of tea plants, eventually nibbling on the bark. For decades, the primary control measure has been high-dose spraying during the peak infestation period. This pesticide application can easily lead to excessive pesticide residues in tea, compromising the health of tea for consumption and export. It also kills natural enemies, disrupts biodiversity, triggers the resurgence of secondary pests, and fosters pesticide resistance. The gray tea looper produces many generations annually, is highly fertile, and exhibits strong pesticide resistance. This often results in a 10% reduction in tea production, with losses exceeding 50% in severe years.

[0003] Insect semiochemical preparations can be used to control pests, requiring minimal dosage for high activity without harming natural enemies. Sex attractants are the most commonly used of these preparations, which are used to ensnare male insects in large numbers, reducing the chances of mating between male and female adults and, consequently, the number of viable eggs. Some plant-based attractants are highly effective in attracting both male and female adults. Recently, compound sex attractants—combinations of sex pheromones and plant-based semiochemicals—have become increasingly popular, offering enhanced potency and killing potential, effectively luring and killing both male and female adults. However, compound sex attractants for the gray tea looper (Ectropis truncatus) have yet to be reported.

[0004] Luo Zongxiu et al. (Luo ZX, Li ZQ, Cai XM, Bian L, Chen ZM. Evidence of premating isolation between two sibling moths: Ectropis grisescens and Ectropis obliqua (Lepidoptera: Geometridae). Journal of Economic Entomology, 2017, 110(6): 2364-2370; Luo Zongxiu, Li Zhaoqun, Cai Xiaoming, Bian Lei, Chen Zongmao. Preliminary study on sex pheromone of gray tea geometrid. Tea Science, 2016, 36(5): 537-543) believed that the sex pheromone of gray tea geometrid is Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-18-carbon diene, and the best effect is achieved when the ratio of the two is 4:6 and the total dose is 1 mg. Ma et al. reported that the sex pheromone of the gray tea geometrid is Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-18-carbon diene, and the best effect is achieved when the ratio of the two is 1:4 and the total dose is 1000 μg (Ma T, Xiao Q, Yu YG, Wang C, Zhu CQ, Sun ZH, Chen XY, Wen X J. Analysis of tea geometrid (Ectropis grisescens) pheromone gland extracts using GC-EAD and GC×GC / TOFMS. Journal of Agricultural and Food Chemistry, 2016, 64(16): 3161-3166). Our research group (CN201010162243.7) has developed a plant-based tea geometrid attractant that can attract the gray tea geometrid's closely related species, the tea geometrid. Furthermore, in production practice, host plant volatiles have been found to enhance the effects of pest pheromones. However, there are no reports of volatiles from the host plant tea tree enhancing the effects of the gray tea looper's sex pheromone. What is certain is that the combination of pest sex pheromones and host plant volatiles is more effective than the pest sex pheromone itself. If the gray tea looper's sex pheromone can be identified, synthesized, and formulated into a sex attractant, which can be used to lure and kill male adults and reduce the chance of mating between male and female adults, sex attractants will become an important means of controlling the gray tea looper.

[0005] The present invention is to screen out suitable tea plant volatiles, and then combine them with the main pheromones of gray tea geometrids to develop a composite sex attractant with more significant attractant effect. Summary of the Invention

[0006] The present invention provides a composite sex attractant for gray tea geometre and its application. The purpose is to use tea plant volatiles and gray tea geometre sex pheromones to formulate the composite sex attractant for gray tea geometre, which is used to attract and kill a large number of second-generation gray tea geometre male adults and some female adults that are relatively uniformly distributed, thereby reducing the chances of male and female mating and significantly reducing the number of gray tea geometre larvae, the main pest generation, i.e., the third generation. This reduces the need for pesticide application to control gray tea geometre.

[0007] The present invention first discloses a composite sex attractant for gray tea geometre and a preparation method of the composite sex attractant. The composite sex attractant comprises the following steps: dissolving linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol and 6-methyl-5-heptene-2-one derived from tea tree volatiles, and two main sex pheromone compounds of gray tea geometre, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene, in a solvent in a mass ratio of 2-4:2-4:2-4:2-4:2-4:2-4:0.4-1.0:0.6-1.2 to form the composite sex attractant for gray tea geometre.

[0008] The present invention also provides a lure core based on the composite sex attractant, which is made by loading the composite sex attractant onto a wool felt strip and sealing it with a plastic film. The contents of linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-hepten-2-one, Z,Z,Z-3,6,9-octadecatriene, and Z,Z-3,9-6,7-epoxy-octadecadiene in each lure core are 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 0.4-1.0 mg, and 0.6-1.2 mg, respectively. Preferably, the contents of linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-hepten-2-one, Z,Z,Z-3,6,9-octadecatriene, and Z,Z-3,9-6,7-epoxy-octadecadiene in each lure core of the sex attractant are 2 mg, 2 mg, 2 mg, 2 mg, 2 mg, 2 mg, 0.4 mg, and 0.6 mg, respectively. The preferred solvent is n-hexane.

[0009] Preferably, after the composite sex attractant is loaded onto each lure core, 1 mg of 2,6-di-tert-butyl-4-methylphenol (BHT) is loaded as a stabilizer.

[0010] The present invention also discloses a method for trapping and killing the gray tea geometrid using the gray tea geometrid composite sex attractant, which is achieved by the following steps:

[0011] 1) Linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-hepten-2-one, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene are dissolved in n-hexane and prepared into a composite sex attractant in a mass ratio of (10):(10):(10):(10):(10):(10):(2-5):(3-6). The loading amount on each lure core is 13.0-26.2 mg.

[0012] 2) The composite sex attractant is loaded onto a wool felt strip to form a lure core. Each lure core has a total signaling substance content of 13.0-26.2 mg. The lure core is attached to a khaki-colored insect trap evenly coated on both sides with colorless and odorless insect glue. The insect trap is hung on a bamboo stick, which is inserted into the tea leaves. The bottom edge of the lure is slightly higher than the tea leaves.

[0013] 3) The distance between the insect attracting boards carrying the attracting core is 30m-40m.

[0014] 4) The time to fix the sex attractant core in the tea garden is mid to late June. During the trapping period, the khaki insect trap board is replaced once, but the core does not need to be replaced.

[0015] Compared to existing technologies, this invention combines linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, and 6-methyl-5-hepten-2-one, volatile compounds derived from tea plants, with two key sex pheromones of the gray tea geometre: Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene. This compound sex attractant and an antioxidant (2,6-di-tert-butyl-4-methylphenol) are dripped onto wool felt, which is then sealed with plastic film to form a composite sex attractant core. This composite sex attractant core is attached to a khaki sticky insect board to form a composite sex attractant trap. The gray tea geometre produces six to seven generations per year in East China, with the first and second generations occurring relatively evenly. The third generation is the primary pest, with larvae chewing tea tree branches and leaves, even bark. The peak season for third-generation larvae is early to mid-July. Mid-to-late June is the peak period for adult emergence. Use traps with compound sex attractants to trap and kill female and male gray tea geometrids that are gravid but have not yet laid eggs. Place traps 30-40 meters apart. Replace sticky insect boards once during the trapping period, but do not replace the lure cores. This can effectively reduce the third-generation larval population in early to mid-July and help keep the fourth to seventh generations of gray tea geometrids low.

[0016] Use compound sex attractants to kill male and female adults of the gray tea looper, reduce the chances of mating between the female and male adults, and thus significantly reduce the number of eggs and larvae of the next generation, thus protecting tea trees from damage caused by the gray tea looper larvae. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1The male adult of gray tea geometre has a significant effect on the volatile compounds of 30 tea plants. -6 g / mL dose of antennal electrophysiological responses;

[0018] Figure 2 The male adult of gray tea geometre has a significant effect on the volatile compounds of 30 tea plants. -4 g / mL dose of antennal electrophysiological responses;

[0019] Figure 3 The male adult of gray tea geometre has a significant effect on the volatile compounds of 30 tea plants. -2 g / mL dose of antennal electrophysiological responses;

[0020] Figure 4 For the female adults of gray tea geometrids, the response to volatile compounds of 30 tea plants was 10 -6 g / mL dose of antennal electrophysiological responses;

[0021] Figure 5 For the female adults of gray tea geometrids, the response to volatile compounds of 30 tea plants was 10 -4 g / mL dose of antennal electrophysiological responses;

[0022] Figure 6 For the female adults of gray tea geometrids, the response to volatile compounds of 30 tea plants was 10 -2 g / mL dose of antennal electrophysiological responses. DETAILED DESCRIPTION

[0023] Example 1 Tea tree volatiles that induce strong electrophysiological responses in the antennae of male and female adults of the gray tea geometrid 1 Materials and methods

[0024] 1.1 Flavor Source and Dosage

[0025] Thirty main components from fresh tea shoots and camellia volatiles (Table 1) were selected and each component was divided into 10 -6 g / mL, 10 -4 g / mL and 10 -2 g / mL 3 doses.

[0026] 1.2 Test insects

[0027] In April, gray tea looper larvae were collected from tea gardens in Songyang County, Zhejiang Province, and reared for three generations indoors at China University of Jilin. One-day-old male and female adults that had just emerged from their tails were selected as test insects.

[0028] 1.3 Insect antennae electrophysiological test procedures and data statistical analysis

[0029] An insect electroantennometer was purchased from Syntech in the Netherlands. The left antenna of an adult gray tea looper (E. gambiae) was cut at the base using ophthalmic surgical scissors. A reference electrode filled with electrophysiological saline was inserted through the antennae. The tip of the antennae was slightly cut off and placed over a recording electrode, also filled with electrophysiological saline. The EAG response was calibrated to zero using liquid paraffin before stimulating with a odor source.

[0030] 20 μL of each dose of the test flavor source solution was added to a 5mm×60mm filter paper strip, and the solvent was allowed to evaporate for 30 seconds. The filter paper was then inserted into a 15cm long Pasteur glass tube, which is a small tube for supplying flavor sources. The flavor sources were supplied in a sequence of increasing concentrations, starting from 10 -6 g / mL, 10 -4 g / mL to 10 -2 g / mL. The mouth of the Pasteur glass tube was approximately 1.5 cm from the test antennae. Each odorant application was a single antennal stimulation. After each antennal stimulation, there was a 2-minute pause to allow the airflow to carry away the odorant and allow the odorant receptors to recover.

[0031] Fifteen antennae were tested for each dose of each odor source, with each antennae used only once. The electrical signals generated by the antennae after odor stimulation were amplified by an amplifier (Syntech CS-05), displayed on a computer screen using software (Syntech, Hilversum, the Netherlands), and stored on the computer hard drive.

[0032] Table 1 Names, purity and sources of 30 flavor compounds

[0033]

[0034] 2 Results

[0035] from Figures 1-6 It can be clearly seen that among the 30 flavor source compounds, No. 1 (linalool), No. 2 (trans-2-hexenal), No. 3 (cis-3-hexen-1-ol), No. 17 (n-hexanol), No. 22 (benzyl alcohol) and No. 28 (6-methyl-5-hepten-2-one) can all cause male adults to Figure 1-Figure 3 ), or female adults ( Figure 4-Figure 6 )Strong EAG reaction.

[0036] Example 2 Field testing of the effects of several sex attractants and plant-derived attractants on adults of the gray tea looper

[0037] 1 Materials and Methods

[0038] 1.1 Preparation of sex attractants and plant-derived attractants

[0039] As shown in Table 2, according to references [1] and [2], Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-18-carbon diene were mixed in a ratio of 4:6, and then n-hexane and an antioxidant (Butylated hydroxytoluene, BHT) were added to prepare sex attractant I. According to reference [3], Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-18-carbon diene were mixed in a ratio of 2:8, and then n-hexane and an antioxidant BHT were added to prepare sex attractant II.

[0040] Literature [1] Luo ZX, Li ZQ, Cai XM, Bian L, Chen Z M. Evidence of prematingisolation between two sibling moths: Ectropis grisescens and Ectropis obliqua (Lepidoptera: Geometridae). Journal of Economic Entomology, 2017, 110(6): 2364-2370.

[0041] Reference [2] Luo Zongxiu, Li Zhaoqun, Cai Xiaoming, Bian Lei, Chen Zongmao. Preliminary study on sex pheromones of the gray tea moth. Tea Science, 2016, 36(5): 537-543.

[0042] Literature [3] Ma T, Xiao Q, Yu YG, Wang C, Zhu CQ, Sun ZH, Chen XY, WenXJ. Analysis of tea geometrid (Ectropis grisescens) pheromone gland extracts using GC-EAD and GC×GC / TOFMS. Journal of Agricultural and Food Chemistry, 2016, 64(16): 3161-3166.

[0043] Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-18-decadiene were added to the six antennae-active plant volatiles listed in Table 2 (linalool, trans-2-hexenal, cis-3-hexen-1-ol, n-hexanol, phenylethyl alcohol, and 6-methyl-5-hepten-2-one) at a ratio of 0.4 mg:0.6 mg, respectively, to prepare a sex pheromone / plant-derived pheromone composite attractant. Finally, these six antennae-active compounds (linalool, trans-2-hexenal, cis-3-hexen-1-ol, n-hexanol, phenylethyl alcohol, and 6-methyl-5-hepten-2-one) were mixed in equal amounts, 5 mg each, to prepare a plant-derived attractant.

[0044] To prepare each attractant, add the respective semiochemical and 1 mg of BHT to n-hexane (Table 2), mix thoroughly, and place on a 1.5 cm × 4.5 cm × 1.0 cm piece of wool felt. Seal with polyvinyl chloride film (100 μm thick) to form a lure. Each lure was stored in a refrigerator at -20°C until needed.

[0045] Table 2 Information substances and their contents in each lure core of three sex attractants and one plant-derived attractant

[0046]

[0047]

[0048] 1.2 Comparative test on the attractant effect of sex attractants or plant-derived attractants on adults of the gray tea looper

[0049] White, triangular traps, 20 cm long, were used, produced by Beijing Zhongjie Sifang Biotechnology Co., Ltd. Each trap contained a lure, 1 cm from the base of the trap, which was coated with colorless and odorless insect glue. Four plots covering an area of 1 hm2 were selected in the tea-growing area of Songyang County, Zhejiang Province, from June 18 to 20, June 25 to 27, July 19 to 21, and July 26 to 28, 2020. 2 Four trapping trials were conducted in organic tea gardens covering approximately 100 acres. Each trapping trial consisted of six groups, each containing the five lure types listed in Table 3. Within each group, five triangular traps were arranged in a linear pattern, 30 meters apart, with 30 meters between groups. Each lure type was replicated six times. Each trial lasted three days. The number of gray loopers captured with each lure type was counted daily, and the base was replaced. The differences in attractant efficacy among the five lure types were compared.

[0050] Based on the same method, the same trapping experiment was repeated in the organic tea garden in the tea area of Songyang County from June 18 to 20, June 25 to 27, July 19 to 21, and July 26 to 28, 2021.

[0051] Using the same method, the same trapping experiment was carried out in a pollution-free tea garden in Jingtingshan Tea Farm, Xuancheng City, Anhui Province from June 16 to 18, June 23 to 25, July 17 to 19, and July 24 to 26, 2021.

[0052] 2 Results

[0053] Significant differences in the number of adult gray tea loopers captured by three sex attractants and botanical attractants in tea gardens: Four field trapping trials conducted in organic tea gardens in Songyang County in June 2020 showed that sex attractant I, sex attractant II, a composite sex attractant, and a botanical attractant all captured a significant number of both male and female gray tea loopers. Analysis of variance revealed significant differences among the five treatments (P < 0.05), with the composite sex attractant capturing the greatest number of adults (Table 3).

[0054] Table 3 The number and difference of adults of the gray tea looper killed by three sex attractants and one plant-derived attractant

[0055]

[0056]

[0057] Note: The experiment took place in 2020; the location was Songyang County, Zhejiang Province; the differences between the values with different lowercase letters in the same column reached a significant level (P < 0.05), the same below.

[0058] The same method was used in the same experimental tea garden in Songyang County's tea region. The results of the experiments on trapping gray tea loopers on June 18-20, June 25-27, July 19-21, and July 26-28, 2021, are shown in Table 4. The trapping effect showed that the composite sex attractant had the best trapping effect.

[0059] Table 4 The number and difference of adults of the gray tea looper killed by sex attractants and plant-derived attractants

[0060]

[0061] Note: The trial time is 2021, location: Songyang County, Zhejiang Province.

[0062] Using the same method, the results of the experiments on trapping adult gray tea loopers in the pollution-free tea gardens of Jingtingshan Tea Farm in Anhui Province from June 16 to 18, June 23 to 25, July 17 to 19, and July 24 to 26, 2021, are shown in Table 5. The composite sex attractant was significantly more effective.

[0063] Table 5 The number and difference of adults of the gray tea looper killed by sex attractants and plant-derived attractants

[0064]

[0065]

[0066] Note: The trial will be held in 2021 at Jingtingshan Tea Farm in Anhui Province.

[0067] Example 3 Detection of coloration of gray tea geometrid adults

[0068] 1 Materials and Methods

[0069] 1.1 Insect Attraction Color Plate

[0070] Coated paper sheets measuring 40 cm × 0.20 cm were produced by Hangzhou Chaju Technology Co., Ltd. in 13 colors: fluorescent yellow, beige, jasmine yellow, khaki, orange, earthy brown, dark green, bud green, grass green, fluorescent green, sky blue, bright red, and pure white. A Konica Minolta colorimeter (model CM-3600A) was used, using the absolute measurement method (L*a*b* color difference system) to measure the brightness L, chromaticity coordinates a, and chromaticity coordinates b of each color plate. Five randomly selected pieces of each color plate were tested, and the average values were calculated (Table 6). After color measurement, each plate was evenly coated with colorless and odorless insect glue on both sides, covered with release paper, and stored at room temperature until ready for use.

[0071] Table 6 Brightness and chromaticity of 13 color palettes

[0072]

[0073]

[0074] Note: In the chromaticity coordinate a, “+” represents the red component and “-” represents the green component; in the chromaticity coordinate b, “+” represents the yellow component and “-” represents the blue component.

[0075] 1.2 Trapping methods

[0076] Color plates were suspended from small bamboo skewers using thin wire. The skewers were inserted into tea bushes. The plates were randomly placed, 7-8 meters apart, with their bottom edges slightly above the tea leaves. Trapping was conducted on July 23, 2021, at the Magushan Tea Farm in Xuancheng City, Anhui Province. After 24 hours, the cumulative number of gray tea loopers trapped using plates coated on both sides with colorless and odorless insect glue was measured. Each plate was replicated 15 times. The same method was conducted on July 28, 2021, at a tea garden in Songyang County, Zhejiang Province.

[0077] 2 Results

[0078] Among the 13 colors, khaki was significantly effective in attracting male and female gray tea geometrids. From July 23 to 24, 2021, 13 sticky color plates were used to trap third-generation male and female gray tea geometrids in a pollution-free tea garden at Magushan Tea Farm in Xuancheng City, Anhui Province. The cumulative number of female and male gray tea geometrids trapped on both sides of each plate within 24 hours was investigated. Compared with other color plates, khaki, orange, jasmine yellow, khaki, and fluorescent yellow were significantly more effective (Table 7). From July 28 to 29, 2021, the same method was used in a pollution-free tea garden in Songyang County, Zhejiang Province. Despite the low density of gray tea geometrids in the test tea garden, khaki, orange, jasmine yellow, khaki, and fluorescent yellow attracted the greatest number of male and female gray tea geometrids within 24 hours (Table 7). Therefore, it is believed that the adult looper prefers dark yellow and khaki is the best attractant.

[0079] Table 7 Number of male and female adults of Geometridae grisea trapped with 13 color plates

[0080]

[0081]

[0082] Example 4 Comparison of the Control Effects of Composite Sexual Attractants, Pesticides, and Virus-Thuringia Suspension Concentrates on the Grey Tea Looper 1 Materials and Methods

[0083] 1.1 Experimental setup of four treatments

[0084] In June 2022, a large tea garden in Songyang County, Zhejiang Province, where the gray tea geometrid was a serious problem, was selected and divided into four treatments. Each treatment contained four plots, for a total of 16 plots. The plots were randomly set, with each plot covering an area of 1 mu:

[0085] (1) Compound sex attractant trapping: On June 25, the peak period for the second generation of gray tea geometrids, a compound sex attractant core was attached to a 20 cm × 40 cm, khaki-colored trapping board coated on both sides with colorless and odorless insect glue to form a trap. Each trap was attached to a bamboo stick, which was inserted into the tea rows, with the bottom edge of the trap board 1 cm above the tea canopy surface. Four traps were placed in each plot, 15 m apart.

[0086] (2) Treatment with virus-thuringia suspension: July 12 was the peak period for the 1st to 3rd instar larvae of the third generation of gray tea geometrids. In the four plots of the treatment, the larval population in each plot was surveyed using the five-point sampling method. Each sampling point was a 2m tea row. The tea bushes were divided into two, and the branches and leaves were slapped vigorously to shake off the larvae. The larvae were then caught with plastic sheets and the number of larvae was counted. After the survey, tea core-thuringia suspension was applied. The specification was 1×10 4PIB / μL·Bacillus thuringiensis 2000 IU / μL, a product of Yangzhou Lvyuan Chemical Co., Ltd. The dosage was 500 times that of tea seed·Bacillus thuringiensis suspension concentrate (150 mL / mu), and the mixture was evenly sprayed in each plot.

[0087] (3) Pesticide treatment: Including 4 plots, on July 12, the base number of larvae in each plot was investigated by five-point sampling method, and then 1200 times solution of 2.5% bifenthrin (produced by Qingdao Taiyuan Technology Development Co., Ltd.) was evenly sprayed.

[0088] (4) CK treatment: This also included four plots. On July 12, a five-point sampling method was used to survey the larval population. Then, khaki sticky boards with n-hexane lures, known as n-hexane traps (Table 2), were hung. Four n-hexane traps (CK) were hung in each plot, 15 m apart.

[0089] 1.2 Calculation of the control effect of the four treatments

[0090] On July 14 and July 19, the five-point sampling method was used to investigate the number of larvae in each plot of each treatment, calculate the insect population reduction rate, and calculate the corrected insect population reduction rate.

[0091] Corrected insect population reduction rate (%) = (insect population reduction rate in the control area - insect population reduction rate in the control area) / (100% - insect population reduction rate in the control area) × 100%

[0092] July 27th is the peak period for the third generation of gray tea loopers. Five khaki insect traps were placed in each treated area according to the five-point method to trap the gray tea loopers.

[0093] 2 Results

[0094] As shown in Table 8, the composite sex attractant has the best control effect on the gray tea geometre moth. In this test, it is better than biphenyl polyester and better than virus and thuringia suspension concentrate:

[0095] In the four plots treated with the compound sex attractant, khaki traps with compound sex attractant cores were set up in the tea gardens to kill adult second-generation gray tea loopers before they laid eggs (June 25). A survey of the third-generation gray tea looper larvae in each of the four treatments on July 12 showed that the average population in the compound sex attractant-treated plot (5.3 ± 1.0) was significantly lower than that in the other three treatments (Table 8). This indicates that the compound sex attractant killed a large number of gray tea looper adults starting on June 25, resulting in a low number of third-generation gray tea looper eggs on the tea trees. Subsequently, due to parasitism and predation by natural enemies, as well as agricultural practices, the larval density in the compound sex attractant-treated plot remained low from July 12 to 19, indicating optimal control (Table 8).

[0096] In the four plots in the CK area, eggs and larvae of various instars of the gray tea looper occurred in early to mid-July. The eggs continued to hatch, and the number of larvae reached the highest on July 19 (Table 8).

[0097] In the pesticide-treated area, after application on July 12, the corrected insect population reduction (control efficacy) was 89.5% on July 14, indicating good results. However, five days later, on July 19, the control efficacy dropped to 60.0% (Table 8).

[0098] In the area controlled by virus·Thuringia thuringiensis suspension, after applying NPV·Thuringia thuringiensis suspension on July 12, the control efficiency was 14.1% on July 14; the control efficiency was 86.4% on July 19, which was an excellent control efficiency. However, the average insect population in the four plots (6.3±0.5) was higher than that in the four plots treated with compound sex attractants (5.5±1.3).

[0099] On July 27th, the third generation of gray tea geometrids entered peak eclosion. Five khaki traps were placed in each treatment plot to capture adult geometrids. Each treatment consisted of four plots. The total number of adults trapped over 24 hours in the four plots treated with the compound sex attractant, NPV and thuringia suspension concentrate, 2.5% bifenthrin, and CK treatments was 10, 20, 48, and 48, respectively. This further demonstrates that the compound sex attractant is most effective within the area.

[0100] Table 8 The efficacy and differences of compound sex attractants, chemical pesticides and virus-Thuringia thuringiensis suspension concentrate against gray looper larvae

[0101]

[0102] Note: The values with different lowercase letters in the same row are significantly different (P < 0.05)

[0103] Example 5 Comparison of the attractant efficacy of the composite sex attractant and patent CN201010162243.7 (a plant-based attractant for trapping and controlling tea geometrid adults)

[0104] 1 Materials and Methods

[0105] 1.1 Composite sex attractant and semiochemical composition of CN201010162243.7

[0106] The composition of the composite sex attractant is: linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethanol and 6-methyl-5-hepten-2-one, as well as Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene. The contents of the eight semiochemicals in each attractant core are 2mg, 2mg, 2mg, 2mg, 2mg, 2mg, 0.4mg and 0.6mg respectively.

[0107] The attractant CN201010162243.7 is composed of menthol, menthone, and linalool in a ratio of 1:1:1. Each lure core contains 8mg, 8mg, and 8mg, respectively.

[0108] For these two types of bait cores, when in use, one bait core is attached to a 20cm×40cm khaki insect trap board coated with colorless and odorless insect glue on both sides to form a trap. The trap is tied to a bamboo stick, which is inserted into the tea row so that the bottom edge of the insect trap board is slightly higher than the top of the tea tree.

[0109] 1.2 Comparative test in tea garden

[0110] On July 5, 2023, during the peak period of first-instar larvae of the third generation of gray tea geometrids, a pollution-free tea garden covering 15 mu (approximately 1.5 acres) was selected in Gushi Town, Songyang County, Zhejiang Province, where tea trees showed consistent growth and gray tea geometrids had been infested over the years. The garden was divided into three sections. One section was designated a trapping area with a compound sex attractant; the middle 5 mu (approximately 1.5 acres) was designated an isolation zone, where no control measures were applied; and the other section was designated a trapping area with the attractant CN 201010162243.7. Within the compound sex attractant trapping area, the isolation zone, and the CN 201010162243.7 trapping area, 20 plots were randomly selected using the parallel jumping method. Each plot consisted of a 1-meter-wide tea row and was divided lengthwise into two sections. Branches and leaves in each section were slapped to shake off gray tea geometrid larvae, which were then collected with plastic sheeting and counted. The number of larvae in the compound sex attractant trapping area, the middle isolation zone, and the CN201010162243.7 attractant trapping area was 204, 205, and 204, respectively. After counting, the larvae were returned to the tea trees.

[0111] On July 25, 2023, the third generation of gray tea looper adults began to emerge (16% of pupae emerged), in the compound sex attractant trapping area, per mu (667m 2 ) Place two traps, and in the CN 201010162243.7 attractant killing area, each mu (667m 2 ) Place 12 traps. Trapping continues for 20 days. When more adults of the gray tea looper are trapped on the color board, replace the trapping board.

[0112] 2 Results

[0113] On August 5, 2023, during the peak infestation of the fourth generation of gray tea geometrid larvae, the same method was used to determine the number of larvae in the compound sex attractant trap, the intermediate isolation zone, and the CN 201010162243.7 trap: 88, 300, and 105, respectively. The population reduction rates were 56.9%, -46.3%, and 48.5%, respectively. The corrected population reduction rates (control effectiveness) of gray tea geometrid larvae in the compound sex attractant trap and the CN 201010162243.7 trap were 70.5% and 64.8%, respectively.

[0114] Therefore, it is believed that the composite sex attractant is more effective in killing adults of the gray tea looper than the CN 201010162243.7 attractant.

[0115] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A composite sex attractant for gray tea looper, characterized in that The preparation method of the composite sex attractant is as follows: linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol and 6-methyl-5-heptene-2-one derived from tea tree volatiles, and two main sex pheromone compounds of gray tea geometre Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene, are dissolved in a solvent in a mass ratio of 2-4:2-4:2-4:2-4:2-4:2-4:2-4:0.4-1.0:0.6-1.2 to form the composite sex attractant for gray tea geometre.

2. The composite sex attractant according to claim 1, characterized in that The solvent is n-hexane.

3. An attractant core based on the composite sex attractant according to claim 1, characterized in that: The composite sex attractant is loaded onto a wool felt strip and sealed with a plastic film to prepare an attractant core. The contents of linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-heptene-2-one, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene in each attractant core are 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 0.4-1.0 mg and 0.6-1.2 mg, respectively.

4. A method for trapping and killing gray tea loopers based on the composite sex attractant according to claim 1, characterized in that: This is achieved by following these steps: 1) dissolving linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-hepten-2-one, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene in n-hexane to prepare a composite sex attractant; 2) The composite sex attractant is placed on a wool felt strip and sealed with a plastic film to prepare an attractant core. The contents of linalool, trans-2-hexenal, cis-3-hexen-1-ol, hexanol, phenylethyl alcohol, 6-methyl-5-heptene-2-one, Z,Z,Z-3,6,9-octadecatriene and Z,Z-3,9-6,7-epoxy-octadecadiene in each attractant core are 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 2-4 mg, 0.4-1.0 mg and 0.6-1.0 mg, respectively. 1.2mg, the total content of the above-mentioned composite sex attractant on each lure core is 13.0-26.2mg, the lure core is attached to a khaki insect trap, the insect trap is hung on a bamboo stick, the bamboo stick is inserted into the tea leaves, and the bottom edge of the insect trap is slightly higher than the tea leaves. 3) Fix the insect traps in the tea garden and control the spacing between the insect traps carrying the trap cores to be 30m-40m; trap and kill the gray tea looper.

5. The method according to claim 4, characterized in that After each lure core is loaded with the composite sex attractant, 1 mg of 2,6-di-tert-butyl-4-methylphenol (BHT) is loaded as a stabilizer.

6. The method according to claim 4, characterized in that In the step 3), the insect trapping board is fixed in the tea garden in mid-to-late June. The khaki insect trapping board is replaced once during the trapping period, but the trap core is not replaced.

7. The method according to claim 4, characterized in that The size of the khaki insect attracting plate is 20cm×40cm.

8. The method according to claim 4, characterized in that Both sides of the khaki insect attracting board are evenly coated with colorless and odorless insect glue.

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