An attractant composition and use thereof

Abstract

The application discloses an attractant composition which is composed of cis-9-tetradecenyl acetate and 3-methyl-2-butanol with a mass ratio of (1-4):(1-4). It is found for the first time that cis-9-tetradecenyl acetate has an attracting effect on both female and male Harmonia axyridis, 3-methyl-2-butanol can increase the attracting effect of cis-9-tetradecenyl acetate on Harmonia axyridis, and 3-methyl-2-butanol also has a certain attracting effect on Harmonia axyridis. Therefore, cis-9-tetradecenyl acetate or the combination of cis-9-tetradecenyl acetate and 3-methyl-2-butanol can be used to attract Harmonia axyridis in a local area, improve the population density of Harmonia axyridis, so that the utilization rate of Harmonia axyridis in a field can be improved, and the biological control efficiency of Harmonia axyridis can be enhanced.

Description

Technical Field

[0001] This invention relates to the field of attractant technology, and more specifically to an attractant composition and its application. Background Technology

[0002] The fall armyworm, one of the world's top ten pests, causes immense damage to crops. Its spread and invasion of my country poses a significant threat to the country's food security. The multicolored ladybug (Harmonia axyridis), belonging to the family Coleoptera, is an important predatory natural enemy insect widely distributed worldwide. The multicolored ladybug's development involves four stages: egg, larva, pupa, and adult. It is characterized by its large appetite, long lifespan, adaptability, and high reproductive capacity. The multicolored ladybug preys on aphids, lepidopteran eggs and larvae, leafhoppers, whiteflies, and many other agricultural pests, making it a crucial ecological factor in fulfilling the ecosystem services of farmland. The multicolored ladybug exhibits high predatory potential in many habitats, playing a vital role in the biological control of pests.

[0003] Natural enemy insects primarily locate their hosts or prey using chemical pheromones. The multicolored ladybug is an important predatory natural enemy of the fall armyworm. Besides artificial breeding and release, using chemical pheromones released by agricultural pests to attract them is also a crucial method. Agricultural pest chemical pheromones are trace chemical substances secreted and released by pests that regulate the behavior of both pests and their natural enemies; they are the most important way for natural enemies to locate pests or their habitats. The fall armyworm is classified as a Class A crop pest by the Ministry of Agriculture and Rural Affairs. Theoretically, the maximum predation rate of a multicolored ladybug on a first-instar fall armyworm larva is 249, and adult female multicolored ladybugs have an even stronger predatory ability against fall armyworm larvae. Therefore, it has a strong control effect on fall armyworm larvae.

[0004] By leveraging the specific characteristics of insects, attractants can effectively attract specific insects, thereby disrupting their reproduction and controlling their populations. Therefore, conducting behavioral regulation research on the fall armyworm, a major agricultural pest, using its sex pheromones, and developing behavioral regulators that precisely target the fall armyworm and other important pests, is beneficial for improving the control of these pests. Summary of the Invention

[0005] In view of the above-mentioned prior art, the purpose of this invention is to provide an attractant composition and its application. This invention uses antennal potential (EAG) and Y-tube olfactory measurement techniques to discover that the sex pheromone component of fall armyworm, cis-9-tetradecene acetate, has a significant attraction effect on its predatory natural enemy, the ladybug, and the addition of 3-methyl-2-butanol can significantly improve the attraction effect of cis-9-tetradecene acetate on ladybugs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The present invention provides a first aspect of an attractant composition for ladybugs, the attractant composition comprising cis-9-tetradecene acetate and 3-methyl-2-butanol in a mass ratio of (1-4):(1-4).

[0008] Preferably, the mass ratio of cis-9-tetradecene acetate to 3-methyl-2-butanol is 1:1.

[0009] A second aspect of the present invention provides the use of the above-described attractant composition in attracting ladybugs.

[0010] Preferably, the attractant composition is used with n-hexane as a solvent, and the concentration of cis-9-tetradecene acetate in the attractant composition is from 0.001 μg / μL to 0.1 μg / μL, and the concentration of 3-methyl-2-butanol in the attractant composition is from 0.001 μg / μL to 0.1 μg / μL.

[0011] Preferably, the ladybugs include both female and male individuals.

[0012] Sex pheromones possess advantages such as specificity, high efficiency at low concentrations, and non-toxicity. This invention is the first to discover that cis-9-tetradecenoyl acetate, a sex pheromone component of the fall armyworm, has a significant attraction effect on its predatory natural enemy, the ladybug *Heterochromis heterophylla*. The addition of 3-methyl-2-butanol significantly enhances the attraction effect of cis-9-tetradecenoyl acetate on *Heterochromis heterophylla*, and 3-methyl-2-butanol also has a certain attraction effect on *Heterochromis heterophylla*. This invention combines cis-9-tetradecenoyl acetate with 3-methyl-2-butanol, resulting in a synergistic effect in enhancing the attraction effect on *Heterochromis heterophylla*.

[0013] The beneficial effects of this invention are:

[0014] This invention is the first to discover that cis-9-tetradecene acetate has an attraction effect on both female and male *Harmonia acuminata*. 3-Methyl-2-butanol can enhance the attraction effect of cis-9-tetradecene acetate on *Harmonia acuminata*, and 3-methyl-2-butanol also has a certain attraction effect on *Harmonia acuminata*. Therefore, using cis-9-tetradecene acetate or a combination of cis-9-tetradecene acetate and 3-methyl-2-butanol can attract *Harmonia acuminata* in localized areas, increasing its population density, thereby improving the utilization rate of *Harmonia acuminata* in the field and enhancing its biological control efficacy. Attached Figure Description

[0015] Figure 1 Absolute EAG response values ​​of cis-9-tetradecene acetate to the antennae of female and male ladybugs;

[0016] Figure 2: The Y-tube olfactory response of female and male Heterochromatic ladybugs to cis-9-tetradecene acetate;

[0017] Figure 3 The attraction effect of a combination of cis-9-tetradecene acetate and 3-methyl-2-butanol on ladybugs. Detailed Implementation

[0018] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] As described in the background art, based on this, in order to develop an attractant with excellent effect on the ladybug, the present invention discovered, through antennal potential (EAG) and Y-tube olfactory measurement techniques, that the sex pheromone component of the fall armyworm, cis-9-tetradecene acetate, has a significant attraction effect on its predatory natural enemy, the ladybug.

[0020] Preparation of cis-9-tetradecene acetate solution:

[0021] Using hexane as a solvent, 10 μL (density 0.87 g / mL) of cis-9-tetradecene acetate was diluted to a total volume of 8.70 mL and mixed thoroughly to obtain a cis-9-tetradecene acetate solution with a concentration of 1 μg / μL. 100 μL of the 1 μg / μL cis-9-tetradecene acetate solution was mixed with 900 μL of hexane to obtain a cis-9-tetradecene acetate solution with a concentration of 0.1 μg / μL. 100 μL of the 0.1 μg / μL cis-9-tetradecene acetate solution was mixed with 900 μL of hexane to obtain a cis-9-tetradecene acetate solution with a concentration of 0.01 μg / μL. Mix 100 μL of a 0.01 μg / μL solution of cis-9-tetradecene acetate with 900 μL of n-hexane to obtain a 0.001 μg / μL solution of cis-9-tetradecene acetate.

[0022] Antennae potential test:

[0023] Adult female and male *Heterochromis heterochromis* were selected as experimental subjects. Using ophthalmic surgical scissors, the antennae of both female and male *Heterochromis heterochromis* were cut off from the base. Each dissected antenna was immediately fixed to two metal electrodes using electrode gel (Spectra 360 electrode gel). 10 μL each of the five concentrations (0.0001, 0.001, 0.01, 0.1, 1 μg / μL) of cis-9-tetradecene acetate solution and n-hexane (blank control) were added to 0.5 × 5 cm filter paper strips, and the filter paper strips were placed in 1 mL Pasteur tubes as stimuli. The instrument baseline was observed, and after the baseline stabilized, the foot pedal was depressed to stimulate the antennae. The stimulation controller released air at a rate of 0.4 mL / s for 0.5 s, allowing a 15 s interval between consecutive stimulations to allow the antennae to recover and stabilize. EAG recordings of 15 antennae were required for each stimulus. Signal storage and analysis were performed using EAG ver.2.5 software (Synthech, Hilversum, Netherlands).

[0024] The formula for calculating the absolute EAG response value of ladybug antennae is: Absolute EAG response value = Test odor response value – Control group response value. Independent samples t-tests were performed on the absolute EAG response values ​​of the treatment and control groups in both female and male subjects using SPSS Statistics 20.0 (IBM Crop, Armonk, New York). The experimental results are as follows: Figure 1 As shown.

[0025] Figure 1 The results showed that all five concentrations of cis-9-tetradecene acetate solution induced significant electrophysiological responses in the antennae of both male and female Heterochromis heterochromis, indicating that both male and female Heterochromis heterochromis can sense cis-9-tetradecene acetate.

[0026] Y-tube olfactory test:

[0027] Y-tube olfactometer (main arm: 20.0 cm long, 1.5 cm in diameter; two lateral arms: 15.0 cm long, 1.5 cm in diameter, with an included angle of 75°). The two arms are connected to flow meters via Teflon tubing. Air is pumped in through an activated carbon filter, rehumidified through a bottle containing deionized water, and then guided into the two arms of the olfactometer. Using hexane as a control, the behavioral responses of female and male adult *Harmonia axyridis* to five different concentrations (0.0001, 0.001, 0.01, 0.1, 1 μg / μL) of cis-9-tetradecene acetate solution were measured. 10 μL of each test solution was applied to a 2×1 cm filter paper strip. 2On the olfactory instrument, after the solvent evaporated for 1 minute, a filter paper strip was inserted into the odor source glass bottle connected to one arm of the olfactory instrument. A control glass bottle connected to the other end of the olfactory instrument contained a filter paper strip treated with 10 μL of n-hexane. Ladybugs that made a cross-arm selection within 5 minutes were considered responsive, and data were recorded. Insects that did not make a selection within 5 minutes were considered unresponsive. Twenty-five valid data points were recorded for each treatment; unresponsive individuals were not recorded. The olfactory instrument was rotated 90° after each test to avoid any directional bias. After 5 repetitions, the olfactory instrument was thoroughly cleaned and rinsed with acetone. The entire testing process was conducted in a dark room to avoid the influence of uneven ambient light. A chi-square test was used. 2 The number of selections was statistically analyzed. The experimental results are as follows: Figure 2 As shown.

[0028] Figure 2 The results showed that 0.0001–0.1 μg / μL of cis-9-tetradecenoyl acetate significantly attracted male adult *Harmonia aurea*; 0.001–0.1 μg / μL of cis-9-tetradecenoyl acetate also attracted female adult *Harmonia aurea*. In conclusion, 0.001–0.1 μg / μL of cis-9-tetradecenoyl acetate exhibited the best attraction for adult *Harmonia aurea*.

[0029] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0030] The test materials used in the embodiments of this invention are all conventional test materials in the art and can be purchased through commercial channels.

[0031] Example 1

[0032] Preparation of attractants:

[0033] (1) Preparation of cis-9-tetradecene acetate solution:

[0034] Using hexane as a solvent, 10 μL (density 0.87 g / mL) of cis-9-tetradecene acetate was diluted to a total volume of 8.70 mL and mixed thoroughly to obtain a cis-9-tetradecene acetate solution with a concentration of 1 μg / μL. 100 μL of the 1 μg / μL cis-9-tetradecene acetate solution was mixed with 900 μL of hexane to obtain a cis-9-tetradecene acetate solution with a concentration of 0.1 μg / μL. 100 μL of the 0.1 μg / μL cis-9-tetradecene acetate solution was mixed with 900 μL of hexane to obtain a cis-9-tetradecene acetate solution with a concentration of 0.01 μg / μL.

[0035] (2) Preparation of 3-methyl-2-butanol solution: Using hexane as solvent, take 10 μL (density 0.818 g / mL) of 3-methyl-2-butanol and dilute to a total volume of 8.18 mL. Mix well to obtain a 3-methyl-2-butanol solution with a concentration of 1 μg / μL. Take 100 μL of the 1 μg / μL 3-methyl-2-butanol solution and mix with 900 μL of hexane to obtain a 3-methyl-2-butanol solution with a concentration of 0.1 μg / μL. Take 100 μL of the 0.1 μg / μL 3-methyl-2-butanol solution and mix with 900 μL of hexane to obtain a 3-methyl-2-butanol solution with a concentration of 0.01 μg / μL.

[0036] Mix 2 mL each of 0.01 μg / μL cis-9-tetradecene acetate and 0.01 μg / μL 3-methyl-2-butanol to prepare a mixed solution with a mass ratio of 1:1 for cis-9-tetradecene acetate and 3-methyl-2-butanol.

[0037] Experimental Example

[0038] Inducement test:

[0039] Y-tube olfactometer (main arm: 20.0 cm long, 1.5 cm in diameter; two lateral arms: 15.0 cm long, 1.5 cm in diameter, with an included angle of 75°). The two arms are connected to flow meters via Teflon tubing. Air is pumped in through an activated carbon filter, rehumidified through a bottle containing deionized water, and then guided into the two arms of the olfactometer. Using hexane as a control, the behavioral selection responses of adult female and male *Heterochromis heterophylla* were tested to those induced by a mixture of 0.01 μg / μL cis-9-tetradecenoate, 0.01 μg / μL 3-methyl-2-butanol, and a 1:1 mass ratio of 0.01 μg / μL cis-9-tetradecenoate and 0.01 μg / μL 3-methyl-2-butanol. 10 μL of each test solution was applied to a 2×1 cm filter paper strip. 2 On the olfactory instrument, after the solvent evaporated for 1 minute, a filter paper strip was inserted into the odor source glass bottle connected to one arm of the olfactory instrument. A control glass bottle connected to the other end of the olfactory instrument contained a filter paper strip treated with 10 μL of n-hexane. Ladybugs that made a cross-arm selection within 5 minutes were considered responsive, and data were recorded. Insects that did not make a selection within 5 minutes were considered unresponsive. Twenty-five valid data points were recorded for each treatment; unresponsive individuals were not recorded. The olfactory instrument was rotated 90° after each test to avoid any directional bias. After 5 repetitions, the olfactory instrument was thoroughly cleaned and rinsed with acetone. The entire testing process was conducted in a dark room to avoid the influence of uneven ambient light. A chi-square test was used. 2 The number of selections was statistically analyzed.

[0040] Figure 3The results showed that 0.01 μg / μL of 3-methyl-2-butanol had a certain attraction to *Harmonia aurea*, with a greater attraction to females than males. A 1:1 mixture of 0.01 μg / μL of cis-9-tetradecenoyl acetate and 0.01 μg / μL of 3-methyl-2-butanol significantly attracted both adult female and male *Harmonia aurea*. Compared to 0.01 μg / μL of cis-9-tetradecenoyl acetate alone, the 1:1 mixture of cis-9-tetradecenoyl acetate and 3-methyl-2-butanol significantly enhanced the attraction of adult *Harmonia aurea*. This indicates that a 1:1 mixture of 0.01 μg / μL of cis-9-tetradecenoyl acetate and 0.01 μg / μL of 3-methyl-2-butanol increased the attraction of cis-9-tetradecenoyl acetate to *Harmonia aurea*.

[0041] Field experiments:

[0042] The experiment included three treatment groups and one control group. The first treatment group consisted of a 1:1 mixture of 0.01 μg / μL cis-9-tetradecene acetate and 0.01 μg / μL 3-methyl-2-butanol; the second treatment group consisted of 0.01 μg / μL cis-9-tetradecene acetate; and the third treatment group consisted of 0.01 μg / μL 3-methyl-2-butanol. All solutions were added to lures, while hexane was added to the lures in the control group. After the hexane evaporated, the lures were placed in the traps. The amount of solution added to each group was the same. The traps were randomly arranged with a 6m spacing between them. The traps were suspended 0.2m above the plant canopy. The number of ladybugs in the traps was counted on the 10th day after placement. The results are shown in Table 1.

[0043] Table 1. Attraction effect of each group on ladybugs in the field experiment.

[0044]

[0045]

[0046] The results in Table 1 show that a mixed solution of cis-9-tetradecene acetate and 3-methyl-2-butanol at a mass ratio of 1:1 can significantly attract both female and male adult Heterochromis heterochromis, and that cis-9-tetradecene acetate and 3-methyl-2-butanol have a synergistic effect in enhancing the attraction effect of Heterochromis heterochromis.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An attractant composition, characterized in that, The attractant composition consists of cis-9-tetradecene acetate and 3-methyl-2-butanol in a mass ratio of 1:

1.

2. The attractant composition according to claim 1, characterized in that, The attractant composition is prepared by the following method: A cis-9-tetradecene acetate solution with a concentration of 0.01 μg / μL was prepared using n-hexane as a solvent; a 3-methyl-2-butanol solution with a concentration of 0.01 μg / μL was prepared using n-hexane as a solvent; and an attractant composition was prepared by mixing the cis-9-tetradecene acetate solution and the 3-methyl-2-butanol solution at a volume ratio of 1:

1.

3. The use of the attractant composition according to claim 1 or 2 in attracting ladybugs.

4. The application according to claim 3, characterized in that, The ladybugs mentioned include both female and male individuals.

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