Sex attractant for bactrocera dorsalis and application of sex attractant

Abstract

The invention discloses a sex attractant for bactrocera dorsalis and application of the sex attractant. The invention provides a sex attractant for bactrocera dorsalis. The sex attractant for bactrocera dorsalis comprises ethyl laurate, ethyl myristate, cis-9-hexadecenoic acid ethyl ester and ethyl palmitate. The sex attractant provided by the invention can effectively reduce the population density of male adult bactrocera dorsalis in the field, reduce successful mating of female adult bactrocera dorsalis, and reduce the reproduction rate of bactrocera dorsalis. The sex attractant developed by the invention is a novel bactrocera dorsalis attractant, can enrich compound resources for biological prevention and control of bactrocera pests and promote the development of a pest comprehensive prevention and control strategy towards the directions of high efficiency, economy, greenness and the like, and has very high application value.

Description

Technical Field

[0001] This invention belongs to the field of insect sex pheromone technology. More specifically, it relates to a sex attractant for the oriental fruit fly and its application. Background Technology

[0002] The oriental fruit fly (Bactrocera dorsalis Hendel), belonging to the order Diptera, family Tetranychidae, and genus Bactrocera, feeds on crops such as citrus, mango, and banana. The main damage caused by the oriental fruit fly occurs when the female uses her ovipositor to puncture the fruit peel and lay her eggs inside. The larvae hatch and feed on the fruit pulp. After maturing, the larvae emerge from the fruit, pupate in the soil, and then become adults, causing further damage. The larvae bore into the fruit, causing it to turn yellow and, in severe cases, fall off and rot, resulting in devastating damage to the orchard.

[0003] Currently, the main methods for controlling the oriental fruit fly in the field are fruit bagging and methyl eugenol trapping. However, fruit bagging is costly and labor-intensive. Alternatively, methyl eugenol can be used as a commercially available attractant to trap male oriental fruit flies. However, long-term and frequent use of a single compound may lead to decreased pest recognition. Developing a novel oriental fruit fly attractant could effectively mitigate this drawback. Summary of the Invention

[0004] The present invention aims to develop an attractant that can effectively attract adult oriental fruit flies. Through research, the present invention has found that four compounds, namely ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenoate, and ethyl palmitate, have an attractive effect on male oriental fruit flies. Based on the above findings, a sex attractant for oriental fruit flies is provided.

[0005] The purpose of this invention is to provide a sex attractant for the oriental fruit fly and its application.

[0006] The above-mentioned objective of this invention is achieved through the following technical solution:

[0007] This invention identifies four compounds—ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenoate, and ethyl palmitate—from the volatiles on the surface of the oriental fruit fly, and discovers that their combination has a strong attraction effect on the fruit fly.

[0008] Therefore, the present invention provides a sex attractant for the oriental fruit fly, comprising ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenoate, and ethyl palmitate in a mass ratio of (20-22):(14-16):(14-16):(8-10).

[0009] Preferably, the concentration of ethyl laurate is 200-220 mg / mL, the concentration of ethyl myristate is 140-160 mg / mL, the concentration of ethyl cis-9-hexadecenoate is 140-160 mg / mL, and the concentration of ethyl palmitate is 80-100 mg / mL.

[0010] As one of the alternative implementations, the sex attractant uses anhydrous ethanol as a solvent.

[0011] Based on the above-mentioned sex attractant for the oriental fruit fly, the present invention provides the following application solutions:

[0012] The application of the above-mentioned sex pheromones in attracting male oriental fruit flies.

[0013] The application of the above-mentioned combination of sex attractant and oriental fruit fly insecticide in the preparation of products that attract and kill male oriental fruit flies.

[0014] The application of the above-mentioned sex attractants in the control of oriental fruit fly.

[0015] The application of the above-mentioned sex attractants in the prevention and control of plant diseases.

[0016] The application of the above-mentioned sex attractants in interfering with the mating of male oriental fruit flies.

[0017] The application of the above-mentioned sex pheromone in the preparation of products for attracting and killing male oriental fruit flies.

[0018] The application of the above-mentioned sex attractant in the preparation of products that interfere with the mating of male oriental fruit fly (Bactrocera dorsalis).

[0019] The present invention has the following beneficial effects:

[0020] The sex attractant of this invention can effectively reduce the population density of male adult oriental fruit flies in the field, reduce the number of successful matings of females, and lower the reproductive rate of oriental fruit flies. The sex attractant developed in this invention is a novel oriental fruit fly attractant, which can enrich the compound resources for the biological control of fruit fly pests, promote the development of integrated pest management strategies towards high efficiency, economy, and green practices, and has high application value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a Y-shaped olfactory sensor.

[0022] Figure 2 To determine the selectivity of the oriental fruit fly under the influence of different treatment mixtures using a Y-type olfly.

[0023] Figure 3 To determine the selectivity coefficient of the oriental fruit fly under the influence of different treatment mixtures using a Y-type olfactometer.

[0024] Figure 4To determine the attraction coefficient of oriental fruit fly under different treatment mixtures and different attraction times for trap experiments. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0026] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0027] In the following examples, the adult oriental fruit flies used were captured at Yangtao Park in Guangzhou and bred in the laboratory under a photoperiod of 14:10 (light period:dark period) for more than 30 generations. The feed for oriental fruit fly larvae was prepared from corn flour, sucrose, yeast powder, cellulose (paper towel), purified water, hydrochloric acid, and sodium benzoate in a mass ratio of 250:25:25:25:200:2:1. The feed for adult oriental fruit flies was prepared from sucrose and yeast powder in a mass ratio of 3:1.

[0028] The trap experiment in Example 2 refers to the experimental method in the reference "GU F, AI S, CHEN Y, et al. Mutualism promotes insect fitness by fungal nutrient compensation and facilitates fungus propagation by mediating insect oviposition preference[J]. ISME J, 2022, 16(7): 1831-1842."

[0029] Ethyl lauryl acid, ethyl myristate, and ethyl palmitate were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; their product numbers are E809098, E838507, and E808754, respectively.

[0030] Ethyl cis-9-hexadecenoate was purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd., product number BD305869.

[0031] Anhydrous ethanol was purchased from Tianjin Yongda Chemical Reagent Co., Ltd.

[0032] Ethyl lauryl acid, CAS number 106-33-2, has the following structural formula:

[0033]

[0034] Ethyl myristate, CAS number 124-06-1, has the following structural formula:

[0035]

[0036] Ethyl palmitate, CAS number 628-97-7, has the following structural formula:

[0037]

[0038] Ethyl cis-9-hexadecenoate has the CAS number 56219-10-4 and the structural formula is:

[0039]

[0040] Example 1: Determination of the tropism of male oriental fruit fly larvae towards a mixture of ethyl laurate, ethyl myristate, ethyl 9-hexadecenoate, and ethyl palmitate using the Y-type olfactory instrument selection behavior method.

[0041] (I) Experimental Methods

[0042] The selective behavioral response of male oriental fruit fly to a mixture of ethyl laurate, ethyl myristate, ethyl 9-hexadecenoate, and ethyl palmitate was determined using a Y-type olfactometer (insect olfactometer).

[0043] Using anhydrous ethanol as a solvent, mixture solutions for different treatment groups were prepared according to the concentrations of the four fatty acid ethyl esters in Table 1. The concentrations of ethyl laurate, ethyl myristate, ethyl 9-hexadecenoate, and ethyl palmitate in the mixture solutions varied among the different treatment groups. The mixture solutions for treatment groups 2, 3, and 4 were obtained by diluting the mixture solution for treatment group 1 by 10, 50, and 100 times, respectively.

[0044] Table 1 Concentrations of four fatty acid ethyl esters in the mixed solutions of different treatment groups

[0045]

[0046] A diagram of a Y-shaped olfactory sensor is shown below. Figure 1 As shown, the Y-shaped olfly is supplied with flowing air by an air pump at a flow rate of 200 mL / min, followed by activated carbon to purify the air, then purified water for humidification, and finally connected to a round-bottom flask containing an odor source compound. The two arms of the Y-shaped olfly are connected to round-bottom flasks of the same specifications. The experimental group had filter paper containing 100 μL of odor source compound solution (i.e., the treatment group mixture solution) placed in the round-bottom flask (the control group had filter paper containing 100 μL of anhydrous ethanol placed in the round-bottom flask). Natural light LED light source was placed in front of the Y-shaped olfly to promote the selection behavior of the oriental fruit fly.

[0047] The olfactory selection response of male oriental fruit flies to four different concentrations of odorant compounds was measured. Filter paper (1.5cm × 5cm) containing 100μL of the odorant compound solution was placed in a round-bottom flask and connected to the arms of a Y-type olfactometer. After 15 minutes of aeration to remove the anhydrous ethanol odor, the selection behavior was measured. Selection was defined as the male oriental fruit fly entering the Y-type olfactometer and extending more than 3cm beyond the arms; failure to enter the arms within 5 minutes was considered non-selection. Each group consisted of 30 oriental fruit flies. After each selection, the fly was removed before the next fly was selected, and each group was repeated three times. After each experiment, the round-bottom flask and Y-type olfactometer were washed with anhydrous ethanol and water, respectively, and then dried in an oven to avoid residual odor interfering with selection. The selection rate and selection coefficient were calculated using the following formula.

[0048]

[0049]

[0050] (II) Experimental Results

[0051] The results of Y-type olfly assays for the selectivity and selectivity coefficient of *Bactrocera dorsalis* under the influence of different treatment mixtures are as follows: Figure 2 and Figure 3 As shown, the results indicate that the mixtures in different treatment groups all exhibited certain attractant activity against male oriental fruit flies. The concentrations of the four fatty acid ethyl esters varied among the different treatment groups; as the concentration decreased, the selectivity and selection coefficient also decreased. The selectivity rates for treatment groups 1, 2, 3, and 4 were 71.22%, 65.14%, 61.84%, and 53.34%, respectively, and the selection coefficients were 42.43%, 30.29%, 23.69%, and 6.68%, respectively. The selection coefficient for treatment group 1 was approximately 1.4 times that of treatment group 2, approximately 1.8 times that of treatment group 3, and approximately 6.35 times that of treatment group 4. This demonstrates a direct correlation between the concentration of the mixture of the four fatty acid ethyl esters and the selectivity and selection coefficient of male oriental fruit flies.

[0052] Example 2: Indoor trapping method to determine the attractant activity of four fatty acid ethyl esters on male adult oriental fruit fly.

[0053] (I) Experimental Methods

[0054] The selectivity determination in the indoor environment was carried out using a trap experiment, which was conducted in an insect rearing cage measuring 30cm×30cm×30cm.

[0055] Experimental group: The different treatment groups in Example 1 were used as experimental groups, the difference being that liquid paraffin was used as a solvent to prepare the mixture solutions of the different treatment groups;

[0056] Positive control group: methyl eugenol at a concentration of 20 μL / mL (dichloromethane as solvent) was used;

[0057] Negative control group 1: dichloromethane.

[0058] Negative control group 2: Liquid paraffin

[0059] In the positive control group, 100 μL of methyl eugenol solution and its solvent (dichloromethane) were added to filter paper. The filter paper was then placed in the trap bottle. The trap bottles of the positive control group and the negative control group 1 were placed diagonally. The number of insects in the trap bottles of the positive control group and the negative control group 1 were observed and counted at 12 h, 24 h and 36 h.

[0060] 100 μL of the mixture solution and its solvent (liquid paraffin) were added dropwise to filter paper, which was then placed in trap bottles. The trap bottles for the experimental group and negative control group 2 were placed diagonally opposite each other. The number of insects in the trap bottles for both groups was observed and counted at 12 h, 24 h, and 36 h. Each concentration gradient was repeated three times, with 50 insects in each group. After each test, the rearing cages were cleaned, and the trap bottles were rinsed with anhydrous ethanol and water, then dried in an oven to avoid any odor affecting subsequent experiments. Tests were conducted at 28-30℃. The attraction coefficient of the mixture of four fatty acid ethyl esters to male oriental fruit flies was calculated using the following formula.

[0061]

[0062] (II) Experimental Results

[0063] Trapping experiments were conducted to determine the attraction coefficients of the oriental fruit fly under different treatment mixtures and different attraction times. The results are as follows: Figure 4 As shown, the results indicate that:

[0064] Male oriental fruit flies exhibit a clear selective preference for mixtures of four fatty acid ethyl esters. The attraction rate of the four fatty acid ethyl esters to males gradually increases with increasing attraction time, demonstrating a certain degree of sustained effectiveness. Compared with the positive control methyl eugenol, at 36 hours of attraction, the attraction rate of the mixture of four fatty acid ethyl esters in treatment group 2 was 70%, which was not significantly different from the 93.33% attraction rate of methyl eugenol (P = 0.157 > 0.05). At 24 hours of attraction, the attraction rate of the mixture of four fatty acid ethyl esters in treatment group 1 was 98%, which was also not significantly different from the 93.33% attraction rate of methyl eugenol (P = 0.985 > 0.05). This indicates that under continuous attraction conditions, the mixtures of four fatty acid ethyl esters in both treatment groups 2 and 1 can achieve the same attraction effect as methyl eugenol.

[0065] In summary, this invention provides a male adult pheromone fly attractant and its application. The attractant comprises ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenate, and ethyl palmitate, exhibiting good attraction effects, high specificity, and no adverse environmental impact. It has been confirmed that the mixture of these four substances has high attraction activity for male adult pheromone flies, with attraction rates exceeding 30%. Through continuous attraction efficiency testing, the strongest attraction effect was observed at 36 hours, and at the highest concentration, it showed a positive effect consistent with methyl eugenol, indicating a certain degree of persistence. Therefore, the mixture of ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenate, and ethyl palmitate can be used as a sex attractant for male adult pheromone flies or as an attractant synergist, showing potential practical application prospects in the development of integrated pest management.

[0066] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A sex attractant for Bactrocera dorsalis, characterized in that, Ethyl laurate, ethyl myristate, ethyl cis-9-hexadecenoate, ethyl palmitate in a mass ratio of (20-22):(14-16):(14-16):(8-10).

2. The sexual attractant of claim 1, wherein, The concentration of the ethyl laurate is 200-220 mg / mL, the concentration of the ethyl myristate is 140-160 mg / mL, the concentration of the ethyl cis-9-hexadecenoate is 140-160 mg / mL, and the concentration of the ethyl palmitate is 80-100 mg / mL.

3. The sexual attractant according to claim 1 or 2, wherein Anhydrous ethanol is used as the solvent.

4. Use of the sex attractant of any one of claims 1-3 in attracting male B. olearae.

5. Use of the sex attractant of any one of claims 1-3 in combination with a B. olearae pesticide in preparing a product for attracting and killing male B. olearae.

6. Use of the sex attractant of any one of claims 1-3 in controlling B. olearae.

7. Use of the sex attractant of any one of claims 1-3 in controlling plant diseases.

8. Use of the sex attractant of any one of claims 1-3 in interfering with the mating of male B. olearae.

9. Use of the sex attractant of any one of claims 1-3 in preparing a product for attracting and killing male B. olearae.

10. Use of the sex attractant of any one of claims 1-3 in preparing a product for interfering with the mating of male B. olearae.

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