Drosophila melanogaster oviposition inhibitor and controlled release system and application thereof

Abstract

The invention provides a spot wing drosophila melanogaster oviposition inhibitor which is sticky liquid and comprises one or more of the following components in percentage by weight: 0.1-1.0% of salicylaldehyde, 0.1-1.0% of ethyl salicylate, 0.1-1.0% of propyl salicylate, 0.1-1.0% of butyl salicylate and the balance of solvent and water, and the total weight percentage is 100%. The inhibitor can be used for inhibiting oviposition of the wing-spot drosophila, so that harm of the wing-spot drosophila to fruits such as blueberries, raspberries, cherries and waxberries is greatly reduced, meanwhile, the weight of the fruits can be increased, and the economic benefits of planters are increased. The invention also provides a controlled release system containing the inhibitor and a method for inhibiting oviposition of the spotted wing drosophila melanogaster.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural pest control. Specifically, the present invention relates to an oviposition inhibitor for Drosophila suzukii, a controlled release system thereof, and applications thereof. Background Art

[0002] Drosophila suzukii is a serious pest of soft-skinned fruits. The fruits damaged by it mainly include: cherries, blueberries, raspberries, blackberries, and Chinese bayberries, etc. In addition, Drosophila suzukii occasionally appears in grapes, strawberries, apricots, nectarines, persimmons, and other soft-skinned fruits. The per-acre output value of all these fruits is very high. In recent years, with the growth of people's consumption ability, the planting areas of these crops have been increasing. Therefore, Drosophila suzukii has an increasingly greater impact on the agricultural economy.

[0003] In fact, Drosophila suzukii is a tiny fruit fly with strong reproductive ability, but it can penetrate the skin of the fruit with its ovipositor and lay eggs under the fruit surface. And pesticides must be targeted at adult fruit flies to be effective. However, in the prior art, the number of suitable pesticides is small, which enables Drosophila suzukii to reproduce rapidly and have strong resistance selection. In addition, if pesticides are frequently used, pesticide residues will remain on the fruits, causing problems for food safety and the environment.

[0004] Therefore, oviposition inhibition of Drosophila suzukii without toxicological problems is the most environmentally friendly and effective way to control this pest. Developing an effective oviposition inhibitor for Drosophila suzukii has become an urgent problem to be solved currently. Summary of the Invention

[0005] The purpose of the present invention is to provide an oviposition inhibitor for Drosophila suzukii, a controlled release system thereof, and applications thereof.

[0006] To achieve the purpose of the present invention, in the first aspect, the present invention provides an oviposition inhibitor for Drosophila suzukii, which is a viscous liquid and includes one or more of the following components: salicylaldehyde, ethyl salicylate, propyl salicylate, butyl salicylate, wherein the weight percentage of this component is 0.1%-1.0%, and the rest is solvent and water, with the total weight percentage being 100%.

[0007] Preferably, the component is a mixture made from three substances, namely ethyl salicylate, propyl salicylate, and butyl salicylate, in a weight ratio of 1:1:1. The weight percentage of this mixture is 0.1%-1.0%, and the rest is solvent and water, with the total weight percentage being 100%.

[0008] In the second aspect, the present invention provides a control system for inhibiting oviposition of Drosophila suzukii, and the control system contains the aforementioned oviposition inhibitor for Drosophila suzukii.

[0009] Preferably, the control system includes a controlled release device, and the controlled release device is one of the following: a perforated bottle, a sustained release package, and a sustained release tube.

[0010] Preferably, the material of the controlled release device is selected from at least one of the following: glass, high density polyethylene, and low density polyethylene.

[0011] In a third aspect, the present invention provides the use of the Drosophila suzukii spawning inhibitor in inhibiting the spawning of Drosophila suzukii.

[0012] In a fourth aspect, the present invention provides a method for inhibiting the spawning of Drosophila suzukii. 444 - 888 of the aforementioned controlled release devices are arranged per mu in the field for inhibiting the spawning of Drosophila suzukii.

[0013] In a fifth aspect, the present invention provides the use of a Drosophila suzukii spawning inhibitor in increasing the fruit weight.

[0014] Preferably, in the aforementioned use, the Drosophila suzukii spawning inhibitor is sprayed on the fruit at least 14 days before fruit harvest.

[0015] Preferably, in the aforementioned use, the Drosophila suzukii spawning inhibitor is applied to the fruit in the form of a spray composition.

[0016] By means of the above technical solutions, the present invention has at least the following advantages and beneficial effects:

[0017] The present invention provides a Drosophila suzukii spawning inhibitor, which can be used to inhibit the spawning of Drosophila suzukii, thereby greatly reducing the damage of Drosophila suzukii to fruits such as blueberries, raspberries, cherries, and waxberries. At the same time, it can also increase the fruit weight, thus increasing the economic benefits of growers.

[0018] The present invention also provides a controlled release system containing the inhibitor, which has strong practicability and great prospects for popularization and application.

[0019] In addition, the present invention also provides a method for inhibiting the spawning of Drosophila suzukii. The combined use of these substances, devices, and means can jointly constitute an efficient system for controlling Drosophila suzukii, which has high practical value for improving agricultural production efficiency, increasing economic benefits, and protecting the construction of the agricultural environment. Detailed Embodiments

[0020] The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0021] The manufacturers of the candidate compounds used in the following examples are as follows: sunflower oil: COFCO Donghai Grain and Oil Industry (Zhangjiagang) Co., Ltd.; myristic acid: Sangon Biotech (Shanghai) Co., Ltd.; methyl salicylate: Sinopharm Chemical Reagent Co., Ltd., Beijing; ethyl salicylate: Sinopharm Chemical Reagent Co., Ltd., Beijing; propyl salicylate: Shanghai Macklin Biochemical Co., Ltd.; butyl salicylate: Sinopharm Chemical Reagent Co., Ltd., Beijing; salicylaldehyde: Sinopharm Chemical Reagent Co., Ltd., Beijing; salicylic acid: Sinopharm Chemical Reagent Co., Ltd., Beijing; methyl anthranilate: Sangon Biotech (Shanghai) Co., Ltd.; anthranilic acid: Sangon Biotech (Shanghai) Co., Ltd.; undecanoic acid: Shanghai Macklin Biochemical Co., Ltd.

[0022] Example 1 Screening of Compounds for Inhibiting Oviposition in Drosophila suzukii

[0023] A series of candidate compounds were screened to determine their ability as oviposition inhibitors. The screening process involved using solvents such as span 60 at a concentration of 0.05%, which was manufactured by Shanghai Yuanye Bio-Technology Co., Ltd. In water, each candidate compound was prepared as two liquids with weight percentages of 1% and 0.1% using a solvent, such as span 60 at a concentration of 0.05%.

[0024] Mature cherries without pest and disease infections were selected. Every 10 selected cherries were immersed in each of the aforementioned liquid candidate compounds and placed at room temperature for one hour. The cherries soaked in various compounds were placed on absorbent paper towels at the bottom of a 1-liter glass jar. Then, 20 Drosophila suzukii were anesthetized with carbon dioxide gas and transferred to each jar, i.e., 20 anesthetized Drosophila suzukii in each jar. Then, the jars were sealed with fine polyester gauze and further wrapped with rubber bands to cover the jars to prevent the fruit flies from flying out, and they were placed on the laboratory workbench. After 48 hours, the cherries were taken out, transferred to paper cups, uncovered, and placed for another 5 days, and then checked for signs of infection. Each candidate compound was repeated five times. Additionally, a solvent, such as span 60 at a concentration of 0.05%, was used as Control 1 without pesticides. A common pesticide, i.e., containing 1% N,N-diethyl-m-toluamide (DEET), was used as Control 2 with pesticides. The experimental results are shown in Table 1 below.

[0025] Table 1 Screening Results of Candidate Compounds for Inhibiting Oviposition in Drosophila suzukii:

[0026]

[0027]

[0028] The above experimental results show that the highest mortality rate for each candidate compound group was observed in the insecticide-free control group 1. This leads to the conclusion that these candidate compounds act by inhibiting egg laying rather than by toxicity. Based on the values in Table 1, it is further concluded that salicylicaldehyde, ethyl salicylate, propyl salicylate, and butyl salicylate have some effect on egg laying in the spotted wing drosophila. Therefore, salicylicaldehyde, ethyl salicylate, propyl salicylate, and butyl salicylate were also included in the final candidate list.

[0029] Example 2 Controlled Release System Testing of Final Candidate Compounds

[0030] The experiments used the four final candidate compounds in Example 1: salicylaldehyde, ethyl salicylate, propyl salicylate and butyl salicylate, and a mixture thereof in a ratio of 1:1:1:1.

[0031] Three different controlled release systems were selected for testing to determine their suitability for releasing the aforementioned final candidate compounds.

[0032] The first type consisted of 25 mL aluminum-capped glass bottles with low-density polyethylene bags. A 5 mm hole was drilled in the center of each cap, hence the name "perforated bottles." The bottles contained a cellulose wick containing 10 mL of the final candidate compound.

[0033] The second type: sealed high-density polyethylene sustained-release bags with a wall thickness of 0.5 mm. Each sustained-release bag contains 10 ml of the final candidate compound.

[0034] The third type: sealed injection-molded low-density polyethylene sustained-release tubes with a wall thickness of 0.8 mm. Each sustained-release tube contains 10 ml (ml) of the final candidate compound.

[0035] The controlled-release systems were weighed individually, replicated five times, and hung on the same horizontal line for a total of 10 days at room temperature. The release rates were measured after the fifth and tenth days, as shown in Table 2.

[0036] Table 2 Experimental results of releasing the final candidate compounds from three different controlled release systems

[0037]

[0038]

[0039] Based on the above experimental results, it can be concluded that the second and third types, namely, the slow-release bag and the slow-release tube, release more slowly than the first perforated bottle, indicating a longer lifespan and greater utility. Although the slow-release bag and the slow-release tube have roughly similar release rates, the slow-release tube was chosen for subsequent testing due to its greater convenience.

[0040] Example 3 A field experiment on blueberries was conducted on the final candidate compounds to test the oviposition inhibition effect on Drosophila suzukii

[0041] The slow-release control release system used in this experiment was the same as that in Example 2 above, which was a mixture of four final candidate compounds mixed in a ratio of 1:1:1:1

[0042] The experiment was carried out in a large commercial blueberry farm in Yunnan. The blueberries were planted in a large greenhouse with open-sided ventilation and a height of 1.5 meters. To test the final candidate compounds, 10 grams of each final candidate compound and 10 grams of a 1:1:1 mixture of ethyl salicylate, propyl salicylate, and butyl salicylate were selected, for a total of 4 experimental compounds and their mixtures. They were respectively sealed in low-density polyethylene slow-release tubes

[0043] The experiment was designed with four treatment rows, each 10 meters long. Between every two of the four rows, two untreated rows were arranged, for a total of 10 rows. In one of the treatment rows, three treatment plants were selected, and every 10 untreated plants separated each treatment plant. The number of slow-release tubes arranged in sequence was 0 (untreated plants), 5, 10, and 20. Each treatment was repeated three times

[0044] Twenty-eight days after placing the slow-release tubes, 100 mature blueberry berries were randomly collected from each treatment area and inspected for infection. The results are shown in Table 3 below

[0045] Table 3 Experimental results of testing the oviposition inhibition effect on Drosophila suzukii using slow-release tubes on blueberries

[0046]

[0047]

[0048] Based on the above experimental results, it was concluded that arranging 10 and 20 slow-release tubes per 10 meters, that is, equivalent to applying 444 slow-release tubes per mu and applying 888 slow-release tubes per mu, had a better effect on inhibiting Drosophila suzukii oviposition, while arranging 5 slow-release tubes per 10 meters had a poorer effect

[0049] Using the release rates on the 10th day in Table 2, the release amounts of salicylaldehyde, ethyl salicylate, propyl salicylate, and butyl salicylate were 119, 82, 71, and 41 grams per mu per day, respectively. The calculation example is as follows

[0050] One mu of land is 667 square meters. If the row spacing is generally 1.5 meters, then the length is 444 meters. For every 10 meters, 10 slow-release tubes are hung, so 444 slow-release tubes are hung for 444 meters. According to the release rate of the slow-release tubes in Table 2, taking the value on the 10th day, for example, the release rate of salicylaldehyde in Table 2 is 268 mg / day. Multiply 268 by 444 and then divide by 1000 to get 119 grams per mu per day. From this calculation, the release amounts of salicylaldehyde, ethyl salicylate, propyl salicylate, and butyl salicylate are 119, 82, 71, and 41 grams per mu per day respectively.

[0051] Example 4 Conducted a raspberry field experiment on the final candidate compounds to test the oviposition inhibition effect on Drosophila suzukii.

[0052] The compounds used in this experiment were the same as those in Examples 2 and 3.

[0053] The experiment was still carried out on a large commercial raspberry farm in Yunnan. All raspberries were planted on the trellises in a large greenhouse. The ventilation method of the greenhouse was open, and the height was 1.5 meters. To test the final candidate compounds, 5 grams of each compound and 5 grams of a mixture of ethyl salicylate, propyl salicylate, and butyl salicylate in a ratio of 1:1:1 were respectively sealed in low-density polyethylene slow-release tubes.

[0054] The experimental design was the same as that in Example 3. Each treatment was repeated three times.

[0055] After 28 days of placing the slow-release tubes, 50 mature raspberry berries were randomly selected from the center of each treatment area to check for infection. The results are shown in Table 4 below:

[0056] Table 4 Experimental results of testing the oviposition inhibition effect on Drosophila suzukii using slow-release tubes on raspberries

[0057]

[0058] From the experimental results in the above table, it can be concluded that the test results of raspberries are similar to those of blueberries, that is, arranging 10 and 20 slow-release tubes on fruit trees with a row spacing of 10 meters has a better oviposition inhibition effect on Drosophila suzukii. [[ID=2...]]

[0059] Example 5 Under field conditions, a blueberry field experiment was conducted on the final candidate compounds to test the oviposition inhibition effect on Drosophila suzukii.

[0060] Using Span 60 at a concentration of 0.05% as a solvent and water, emulsions of ethyl salicylate, propyl salicylate, butyl salicylate, and a 1:1:1 mixture of these three compounds at concentrations of 1.0% and 0.1% were prepared. Additionally, emulsions of salicylaldehyde at concentrations of 0.1% and 1.0% were prepared using Span 60 at a concentration of 0.05% as a solvent and water. The spraying equipment was a 5-liter sprayer. During spraying, 2 liters of the emulsion was used to evenly spray a 20-meter row of blueberries as a standard. Spraying was carried out twice, with a 7-day interval between each spraying. On day 0, i.e., before application, day 14, i.e., 7 days after the first spraying, and day 21, i.e., 7 days after the second spraying, the infection status of Drosophila suzukii in every 100 berries was evaluated. A group without spraying application was set as control group 1. The average value of 3 replicates was calculated, and the results are shown in Table 5 below.

[0061] Table 5 Statistical experimental results of the infection status of blueberries treated with the final candidate compounds under field conditions

[0062]

[0063] Based on the data in the above table, it can be concluded that ethyl salicylate, propyl salicylate, butyl salicylate at concentrations of 0.1% and 1.0%, their 1:1:1 mixture, and salicylaldehyde can all effectively inhibit the oviposition of Drosophila suzukii. Therefore, the final candidate compounds at concentrations of 1.0% or 0.1% are all applicable concentrations, and the concentration of 0.1% is the optimal one.

[0064] Example 6 Under field conditions, a field trial of the final candidate compounds on cherries was conducted to test the oviposition inhibition effect on Drosophila suzukii.

[0065] Using Span 60 at a concentration of 0.05% as a solvent and water, emulsions of ethyl salicylate, propyl salicylate, butyl salicylate, and a 1:1:1 mixture of these three compounds at concentrations of 1.0% and 0.1% were prepared. Additionally, emulsions of salicylaldehyde at concentrations of 0.1% and 1.0% were prepared using Span 60 at a concentration of 0.05% as a solvent and water. Spraying was carried out evenly at a rate of 2 liters of liquid per 5 cherry trees as a standard, twice with a 7-day interval between each spraying. On day 0, i.e., before application, day 14, i.e., 7 days after the first spraying, and day 21, i.e., 7 days after the second spraying, the infection status of Drosophila suzukii in 100 cherries (20 were selected from each tree) was evaluated. A group without application was set as control group 1. The average value of 3 replicates was calculated, and the experimental results are shown in Table 6 below.

[0066] Table 6 Experimental results of the infection status of cherries treated with the final candidate compounds under field conditions

[0067]

[0068] Based on the above experimental results, it is concluded that ethyl salicylate, propyl salicylate, butyl salicylate with concentrations of 0.1% and 1.0% respectively, their mixture in a ratio of 1:1:1, and salicylaldehyde with concentrations of 0.1% and 1.0% can all effectively inhibit the oviposition of Drosophila suzukii. At the same time, no phytotoxicity of leaves and cherries was detected in the experiment, nor was any peculiar smell found. This indicates that these concentration ratios are all applicable.

[0069] Example 7 Under field conditions, the final candidate compound was used to conduct a field experiment on Chinese bayberry to test the oviposition inhibition effect on Drosophila suzukii.

[0070] Span 60 with a concentration of 0.05% was used as a solvent and water was used to prepare emulsions of ethyl salicylate, propyl salicylate, butyl salicylate with concentrations of 1.0% and 0.1% respectively, and a mixture of these three compounds in a ratio of 1:1:1. Then, Span 60 with a concentration of 0.05% was used as a solvent and water was used to prepare emulsions of salicylaldehyde with concentrations of 0.1% and 1.0%. Spraying was carried out according to the standard of evenly spraying 2 liters of liquid on 5 blueberry trees, and it was done twice with an interval of 7 days. For example, it was sprayed once 7 days after day 0, and then sprayed again on day 14 after an interval of 7 days. On day 0, that is, before application, on day 14, that is, 7 days after the first spraying, and on day 21, that is, 7 days after the second spraying, the infection situation of Drosophila suzukii in 100 berries was evaluated respectively, that is, 20 were selected from each tree. A group without application was set as control group 1. The average value of 3 replicates was calculated, and the experimental results are shown in Table 7 below.

[0071] Table 7 Experimental results of the infection situation of Chinese bayberry treated with the final candidate compound under field conditions

[0072]

[0073] Based on the above experimental results, it is concluded that ethyl salicylate, propyl salicylate, butyl salicylate with concentrations of 0.1% and 1.0% respectively, their mixture in a ratio of 1:1:1, and salicylaldehyde can all effectively inhibit the oviposition of Drosophila suzukii. At the same time, the experiment also proved that these compounds and their mixtures have no phytotoxicity to leaves and fruits, and no peculiar smell was detected.

[0074] Example 8 Under field conditions, the final candidate compound was used to conduct a field experiment on cherries to observe the weight increase of cherries.

[0075] Using Span 60 with a concentration of 0.05% as a solvent and water to prepare emulsions of ethyl salicylate, propyl salicylate, butyl salicylate with concentrations of 1.0% and 0.1% respectively, and their mixture in a ratio of 1:1:1. Then using Span 60 with a concentration of 0.05% as a solvent and water to prepare emulsions of salicylaldehyde with concentrations of 0.1% and 1.0% respectively. When the fruits start to change color, spray these liquids evenly at a rate of 2 liters per 5 trees as a standard and spray twice in the field with a 7-day interval. The spraying time is selected at least 14 days before the cherry fruits are harvested, preferably around 20 - 25 days before harvest. The experiment was conducted 21 days before harvest, and the 21st day before harvest was set as day 0. The first spraying was carried out 7 days later, that is, the 14th day counted from day 0 was 7 days after the first spraying, and the 21st day was 7 days after the second spraying. Weigh 100 cherries. Set a group without application as control group 1, calculate the weight percentage increase of the fruits after spraying compared to the fruits of control group 1 without spraying, and select 20 from each tree. Calculate the average value of 3 replicates, and the results are shown in Table 8.

[0076] Table 8 Experimental results of weight increase after treating cherries with the final candidate compounds under field conditions

[0077]

[0078] Based on the above experimental results, it can be concluded that before the cherry fruits are harvested, applying ethyl salicylate, propyl salicylate, butyl salicylate with a concentration of 0.1% and their mixture in a ratio of 1:1:1 or salicylaldehyde with a concentration of 0.1% on the 14th day, which is 7 days after the first spraying, and the 21st day, which is 7 days after the second spraying, can increase the fruit size. While a concentration of 1% has no effect or slightly adverse effect on the weight increase of cherry fruits.

[0079] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. Oviposition inhibitor of Drosophila suzukii, characterized in that, It is a viscous liquid and contains one or more of the following components: salicylaldehyde, ethyl salicylate, propyl salicylate, butyl salicylate. Among them, the weight percentage of this component is 0.1%-1.0%, and the rest are solvent and water, with the total weight percentage being 100%.

2. The Drosophila suzukii spawning inhibitor according to claim 1, wherein The component is a mixture made from three substances, namely ethyl salicylate, propyl salicylate, and butyl salicylate, in a weight ratio of 1:1:

1. The weight percentage of this mixture is 0.1%-1.0%, and the rest are solvent and water, with the total weight percentage being 100%.

3. A control system for inhibiting the oviposition of spotted-wing drosophila, characterized in that, The control system contains the Drosophila suzukii spawning inhibitor described in claim 1 or 2.

4. The control system according to claim 3, wherein The control system includes a controlled release device, and the controlled release device is one of the following: a perforated bottle, a sustained release package, a sustained release tube.

5. The control system according to claim 4, wherein The material of the controlled release device is selected from at least one of the following: glass, high-density polyethylene, and low-density polyethylene.

6. Use of the Drosophila suzukii spawning inhibitor according to any one of claims 1 or 2 in inhibiting Drosophila suzukii spawning.

7. A method for inhibiting the oviposition of Drosophila suzukii, characterized in that, Arrange 444-888 controlled release devices as described in claim 4 per mu in the field for inhibiting Drosophila suzukii spawning.

8. Use of the Drosophila suzukii spawning inhibitor according to any one of claims 1 or 2 in increasing fruit weight.

9. The application according to claim 8, wherein Spray the Drosophila suzukii spawning inhibitor on the fruit at least 14 days before fruit harvest.

10. The application according to claim 6, characterized in that, The Drosophila suzukii spawning inhibitor is applied in the form of a spray.

Images