Diaphorina citri slow-release attractant and preparation method thereof

Abstract

The invention discloses a diaphorina citri slow-release attractant and a preparation method thereof, the diaphorina citri slow-release attractant is composed of ethyl butyrate, myrcene, p-cymene, a paraffin carrier and cellulose acetate tows, and the ethyl butyrate, the myrcene, the p-cymene and the paraffin carrier are mixed and filled in the cellulose acetate tows. The diaphorina citri slow-release attractant provided by the invention has efficient attraction activity on diaphorina citri adults, the preparation method of the slow-release attractant is simple, low in cost, high in operability and suitable for industrial production, the oxidation and decomposition speed of active ingredients in ethyl butyrate, myrcene and cymene can be reduced by dissolving paraffin, and the effect of inducing diaphorina citri adults is achieved. The active ingredients are stably and continuously released for at least 20 weeks, and the composition is suitable for directly trapping and killing or monitoring diaphorina citri in the field.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural pest trapping and population monitoring, and particularly relates to a citrus psyllid slow-release attractant and a preparation method thereof. Background Art

[0002] Citrus Huanglongbing is a devastating disease for the citrus industry, and citrus psyllid is the only field vector that spreads Huanglongbing. So far, no effective pesticides for the prevention and treatment of Huanglongbing have been found. Cutting off the transmission pathways of citrus psyllid is an important measure for the prevention and control of citrus Huanglongbing. Direct trapping of citrus psyllids or real-time monitoring of citrus psyllid populations is very important for effectively controlling citrus psyllid populations and thus cutting off the transmission pathways of citrus Huanglongbing. The use of yellow sticky insect boards alone to trap or monitor citrus psyllids is not very effective and is far from meeting the requirements of field production applications. Therefore, it is urgent to develop new citrus psyllid attractants and their application technologies, establish a precise prevention and control technology system for citrus psyllids, and ensure the sustainable development of my country's citrus industry.

[0003] There are two reasons why citrus psyllid attractants have not been developed and applied: (1) There is a lack of identification of highly effective citrus psyllid attractant compounds. (2) There is a lack of stable dosage forms that can continuously release attractant compounds. Therefore, the present invention screens out a combination of compounds with strong attractant activity to citrus psyllid adults, and then creates a low-cost, long-lasting sustained-release dosage form, which can provide important technical support for direct trapping and population monitoring of citrus psyllids. Summary of the invention

[0004] The purpose of the present invention is to overcome the difficulty that the existing citrus psyllid trapping technology cannot efficiently attract citrus psyllid adults, and provide a compound combination with strong attractant activity for citrus psyllid adults and a sustained-release type with stable continuous release and long lasting effect, which can improve the trapping activity, realize efficient population monitoring, and help cut off the transmission chain of citrus Huanglongbing disease.

[0005] The first object of the present invention is to provide a citrus psyllid slow-release attractant, which is composed of ethyl butyrate, myrcene, p-cymene, a paraffin carrier and a cellulose acetate tow, wherein the ethyl butyrate, myrcene, p-cymene and the paraffin carrier are mixed and filled in the cellulose acetate tow.

[0006] Preferably, the three attractant compounds of ethyl butyrate, myrcene and p-cymene are mixed with the paraffin carrier in the following volume percentages: 20-50% of the sum of the three attractant compounds of ethyl butyrate, myrcene and p-cymene and 50-80% of paraffin.

[0007] Preferably, the volume ratio of ethyl butyrate, myrcene and p-cymene is (10-20):(5-20):(5-10).

[0008] More preferably, the volume ratio of ethyl butyrate, myrcene and p-cymene is (10-20):(10-20):(5-10).

[0009] Preferably, the acetate fiber bundle is cylindrical, with a diameter of 1.5 cm and a height of 3.0 cm.

[0010] The acetate fiber tow has good liquid permeability and excellent adsorption, and can fully and evenly adsorb a mixture of ethyl butyrate, myrcene, p-cymene and paraffin, and stably and evenly release ethyl butyrate, myrcene and p-cymene during the implementation process, and can reduce the oxidation and decomposition rate of the active ingredients in ethyl butyrate, myrcene and p-cymene, greatly reduce the usage, and stably and continuously release the attractant for at least 20 weeks.

[0011] The second object of the present invention is to provide a method for preparing the above-mentioned citrus psyllid slow-release attractant, comprising the following steps:

[0012] S1. Put solid paraffin into a container and heat until it is completely dissolved to obtain paraffin liquid;

[0013] S2. The ethyl butyrate, myrcene, and p-cymene are mixed into the paraffin liquid to obtain a blend of ethyl butyrate, myrcene, p-cymene and the paraffin liquid;

[0014] S3. Soak the acetate fiber tow in a mixed solution of ethyl butyrate, myrcene, para-cymene and paraffin solution until it is completely absorbed, then take it out and allow it to cool and solidify.

[0015] Preferably, the method for preparing the above-mentioned citrus psyllid slow-release attractant comprises the following steps:

[0016] S1. Put solid paraffin into a beaker, heat to 100°C and stir until the paraffin is completely dissolved to obtain paraffin liquid;

[0017] S2. Ethyl butyrate, myrcene and p-cymene are mixed into the paraffin liquid, heated to 100 ° C and stirred to obtain a blend of ethyl butyrate, myrcene, p-cymene and paraffin liquid;

[0018] S3. Soak the acetate fiber tow in a mixed solution of ethyl butyrate, myrcene, para-cymene and paraffin solution until it is completely absorbed (no bubbles emerge), and then take it out to cool and solidify.

[0019] The third object of the present invention is to provide the above-mentioned citrus psyllid slow-release attractant for use in trapping or monitoring citrus psyllid.

[0020] Preferably, the citrus psyllid slow-release attractant is used with a matching yellow board or a special trap to directly lure or monitor citrus psyllids.

[0021] The fourth object of the present invention is to provide a product for luring or monitoring citrus psyllids, which comprises the above-mentioned citrus psyllid slow-release attractant.

[0022] The fifth object of the present invention is to provide a method for luring and killing adult citrus psyllids or monitoring the occurrence of citrus psyllid populations, which is to set the above-mentioned citrus psyllid slow-release attractant and matching traps around the citrus orchard to lure adult citrus psyllids.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Since the attractant components in the host plants of citrus psyllids are easily volatile compounds, the present invention uses paraffin as a carrier to overcome instantaneous volatilization and achieve a stable odor release effect.

[0025] (2) The preparation method of the citrus psyllid slow-release attractant is simple and low-cost, and can reduce the rate at which the active ingredient is oxidized and decomposed, greatly reduce the amount used, and stably and continuously release the active ingredient for at least 20 weeks.

[0026] (3) Compared with single yellow cards, bait cores containing slow-release attractants for citrus psyllids can attract more psyllids in the field, which can significantly reduce the labor costs of monitoring / control.

[0027] (4) The synergist component provided by the present invention is low in price, can reduce the cost of making the lure core, has strong operability, and is suitable for popularization and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the slow-release attractant for citrus psyllid.

[0029] Figure 2 This is a flow chart for the production of slow-release attractants for citrus psyllids.

[0030] Figure 3 Schematic diagram of H-type selector.

[0031] Figure 4 The selectivity of citrus psyllids to different slow-release attractants. Note: "**" indicates that the data in the same group are significantly different at the 0.01 level by paired sample t test. "***" indicates that the data in the same group are significantly different at the 0.001 level by paired sample t test.

[0032] Figure 5 Temporal dynamics of the total number of citrus psyllid adults trapped with different attractant formulations. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with specific embodiments. The given examples are only for illustrating the present invention, but not for limiting the scope of the present invention.

[0034] Example 1

[0035] An indoor olfactory behavioral choice experiment of citrus psyllid attractant cores was conducted from July 10 to August 20, 2023 at Zhongkai University of Agriculture and Engineering.

[0036] The attractants with different formulas are shown in Table 1: The main ingredients of the attractants in this test are ethyl butyrate, myrcene and p-cymene, and paraffin is used as the solvent. The volume ratio of the single compound (ethyl butyrate, myrcene and p-cymene) to paraffin is 1:9; the composite formula is prepared by mixing multiple compounds with paraffin in a certain volume ratio (see Figure 1 and Figure 2 ), wherein the volume ratios of ethyl butyrate, myrcene, p-cymene and paraffin are 1:1:1:7 and 2:2:1:5.

[0037] Table 1. Formula of slow-release attractant for citrus psyllid

[0038]

[0039]

[0040] Note: This table shows the percentages by volume.

[0041] The preparation steps of the slow-release attractant are:

[0042] S1. Put solid paraffin into a beaker, heat to 100°C and stir until the paraffin is completely dissolved to obtain paraffin liquid;

[0043] S2. Ethyl butyrate, myrcene and p-cymene are mixed into the paraffin liquid, heated to 100 ° C and stirred to obtain a blend of ethyl butyrate, myrcene, p-cymene and paraffin liquid;

[0044] S3. Soak the acetate fiber tow in a mixed solution of ethyl butyrate, myrcene, para-cymene and paraffin solution until it is completely absorbed (no bubbles emerge), and then take it out to cool and solidify.

[0045] The indoor olfactory selection test was conducted in the Insect Behavior Laboratory of the Yingdong Building of Zhongkai University of Agriculture and Engineering. The indoor temperature was maintained at 25±1℃, the relative humidity was 70-80%, and the light intensity was 12h:12h day and night. Two pots of Murraya osmanthus of the same size and growth without citrus psyllids or other pests were selected and placed in the two side cylinders of the homemade "H"-shaped selector. The prepared attractants were hung in the Murraya osmanthus plants, and the top opening was sealed with plastic wrap to prevent the psyllids from escaping. After 24 hours, 50 adult psyllids (male-female ratio of 1:1) were released into the device from the circular hole of the connecting arm of the test device without removing the psyllids that were feeding, and allowed to choose freely. The number of psyllids that entered the cylinders on both sides was counted respectively (see Figure 3Each attractant test was repeated 5 times, with a total of 250 insects tested.

[0046] Citrus psyllid's selection response to different slow-release attractants: The order of citrus psyllid's response to the tested formulas from large to small is: Formula E (74%), Formula A (66%), Formula B (60.8%), Formula D (60.4%), Formula C (52%), indicating that compound formula E has the strongest attraction rate for citrus psyllid adults.

[0047] Example 2

[0048] From September 1 to 11, 2023, a field attraction test of citrus psyllid slow-release attractant was conducted in an unmanaged citrus orchard in Aotou Town, Conghua District, Guangzhou.

[0049] The attractants with different formulations are shown in Table 1.

[0050] The field trapping test plot was selected in the unmanaged citrus orchard in Aotou Town, Conghua District, Guangzhou City, Guangdong Province. Through field investigation, the orchards seriously infested with citrus psyllids were selected. The insect-carrying plant rate of the sugar orange orchard was 100%, and the average number of insect heads was 45. The sugar orange plot was 1 mu, and the citrus variety planted in the trapping test plot was sugar orange, with an age of 6 to 7 years, an average tree height of 1.6m, an average crown width of 1.7m, a plant spacing of 3.0m, and a row spacing of 3.0m. During the entire trial, no chemical pesticides were used in the test plot, and no citrus psyllids and other pests were controlled.

[0051] From September 1 to September 11, 2023, simple traps were made using slow-release bait cores and yellow bait boards and hung around the periphery of the citrus tree crown 1.8 m from the ground. The bait core with attractant was hung in the center of the yellow bait board and fixed with two iron wires. Each trap was at least 3 m apart. After the bait core was hung, the number of citrus psyllid adults (female and male) attached to the yellow board was recorded from 15:00 to 17:00 every day starting from the second day.

[0052] The attracting effect of different attractants on citrus psyllids: The temporal dynamics of the attracting effect of different attractant formulas on the sugar orange orchard in Aotou Town, Conghua District, Guangzhou Figure 5. From the beginning of trapping on September 1, 2023 to the first citrus psyllid, the number of citrus psyllid adults trapped gradually increased over time. The trend of the number of citrus psyllid adults trapped by the five test treatments was almost the same, and the overall trend was upward. The total amount of trapping by the five attractant formulas was always higher than that of the control (single use of yellow board, CK), among which the number of insects trapped by formula E was significantly higher than that of the other four attractants (A, B, C, D). The trapping effect of each attractant formula on citrus psyllid adults is shown in Table 2. As shown in Table 2, the total number of insects trapped by the control (CK), formula A, B, C, D, and E were 26 (♀10, ♂16), 98 (♀45, ♂53), 54 (♀26, ♂28), 38 (♀24, ♂14), 59 (♀36, ♂23), and 113 (♀67, ♂46), respectively. The order of the average daily insect trapping amount of each treatment from large to small is: formula E, formula A, formula D, formula B, and formula C. Among the single compound formulas, formula A has a better daily trapping effect than formula B and formula C. Among the compound formulas, formula E has a better trapping effect than formula D. This shows that compound formula E has the strongest trapping rate for adult citrus psyllids (see Figure 4 ).

[0053] Table 2. The trapping effect of different attractant formulations on citrus psyllid adults

[0054]

[0055] Note: The data of daily insect trapping amount in the table are mean ± standard error. Different lowercase letters after the data in the same column indicate significant differences (P<0.05).

[0056] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A citrus psyllid slow-release attractant, characterized in that: The invention is composed of ethyl butyrate, myrcene, p-cymene, a paraffin carrier and an acetate fiber bundle. The ethyl butyrate, myrcene, p-cymene and the paraffin carrier are mixed and filled in the acetate fiber bundle.

2. The citrus psyllid slow-release attractant according to claim 1, characterized in that: The three attractant compounds of ethyl butyrate, myrcene and p-cymene are mixed with a paraffin carrier according to the following volume percentages: 20-50% of the total of the three attractant compounds of ethyl butyrate, myrcene and p-cymene and 50-80% of paraffin.

3. The citrus psyllid slow-release attractant according to claim 2, characterized in that: The volume ratio of ethyl butyrate, myrcene and p-cymene is (10-20):(5-20):(5-10).

4. The citrus psyllid slow-release attractant according to claim 3, characterized in that: The volume ratio of ethyl butyrate, myrcene and p-cymene is (10-20):(10-20):(5-10).

5. The citrus psyllid slow-release attractant according to claim 1, characterized in that: The acetate fiber bundle is cylindrical, with a diameter of 1.5 cm and a height of 3.0 cm.

6. A method for preparing the citrus psyllid slow-release attractant according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Put solid paraffin into a container and heat until it is completely dissolved to obtain paraffin liquid; S2. The ethyl butyrate, myrcene, and p-cymene are mixed into the paraffin liquid to obtain a blend of ethyl butyrate, myrcene, p-cymene and the paraffin liquid; S3. Soak the acetate fiber tow in a mixed solution of ethyl butyrate, myrcene, para-cymene and paraffin solution until it is completely absorbed, then take it out and allow it to cool and solidify.

7. Use of the slow-release attractant for citrus psyllid according to any one of claims 1 to 5 in trapping or monitoring citrus psyllid.

8. The use according to claim 7, characterized in that: The citrus psyllid slow-release attractant is used with a matching yellow board or a special trap to directly lure and kill or monitor citrus psyllids.

9. A product for trapping or monitoring citrus psyllids, characterized in that: The invention comprises the slow-release attractant for citrus psyllid according to any one of claims 1 to 5.

10. A method for trapping and killing citrus psyllid adults or monitoring the occurrence of citrus psyllid populations, characterized in that: The citrus psyllid slow-release attractant and the matching trap described in any one of claims 1 to 5 are arranged around a citrus orchard to attract adult citrus psyllids.

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