Application of sucralose in the control of beet armyworm

Abstract

This invention provides the application of tebuconazole in the control of beet armyworm, relating to the field of pest control technology. The tebuconazole can produce a significant antifeedant effect on beet armyworm at a certain concentration, and can also inhibit the growth of beet armyworm larvae to a certain extent, even causing their death. It can be used as a novel beet armyworm control agent. This invention overcomes the shortcomings of existing technologies, using tebuconazole, a plant-derived extract, to effectively control beet armyworm. Furthermore, this ingredient is green and safe, reducing environmental pollution, and has good prospects in the development of novel beet armyworm control agents.

Description

Technical Field

[0001] This invention relates to the field of pest control technology, specifically to the application of styraxic acid in the control of beet armyworm. Background Technology

[0002] The beet armyworm is one of the world's most widely distributed agricultural pests, with over 170 host species, including beets, corn, onions, peanuts, Chinese cabbage, and roses. Beet armyworm outbreaks are most prevalent in autumn due to the low rainfall and mild climate, which are ideal for its growth and reproduction. Therefore, the beet armyworm population in autumn accounts for 61% to 96% of the annual total. Its larvae primarily feed on leaves, tender stems, flower buds, and petals. Young larvae gnaw on the leaf tissue, creating transparent window spots, while older larvae voraciously feed on leaves, causing notches or holes. In severe cases, only the veins remain, and the larvae can also cause malformed flower buds that fail to open, directly impacting the quality of cut flowers.

[0003] Currently, the control of beet armyworm mainly relies on chemical pesticides. However, the long-term and large-scale use of chemical pesticides has led to pesticide resistance in beet armyworms and reduced efficacy of major insecticides, while also causing environmental pollution. Pesticide resistance has become a major challenge in beet armyworm control, necessitating the search for new, green control technologies to reduce reliance on chemical methods.

[0004] Trametenolic acid B is a natural triterpenoid compound extracted from specific fungi, with the molecular formula C. 30 H 48 O3 is currently mainly used in pharmaceutical development and scientific research, and has not been applied in the field of pest control. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides the application of tebuconazole in the control of beet armyworm. Specifically, the use of tebuconazole can effectively induce beet armyworm to refuse to eat and can limit the growth and development of beet armyworm larvae, thus achieving a good control effect.

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

[0007] The application of tebuconazole in the control of beet armyworm, wherein the tebuconazole is used to limit the development of beet armyworm, kill beet armyworm, or inhibit beet armyworm feeding.

[0008] Preferably, the effective inhibitory concentration of the thiabendazole against the beet armyworm is EC. 50 It is 0.067 mg / mL.

[0009] Preferably, the concentration of the thiabendazole is ≥0.25 mg / mL when inhibiting feeding by the beet armyworm.

[0010] Preferably, the application method is to dissolve thiabendazole in a solvent and then spray it on crops to control beet armyworm.

[0011] Preferably, the concentration of the thrombocytidine dissolved in the solvent is ≥0.05 mg / mL.

[0012] This invention provides the application of thiabendazole in the control of beet armyworm, and its advantages compared with the prior art are:

[0013] In this invention, tebuconazole can achieve a good antifeeding effect on beet armyworm at low concentrations, and the antifeeding rate increases with increasing concentration, showing a clear dose-response relationship. Specifically, at a concentration of 0.25 mg / mL, the antifeeding rate against beet armyworm exceeds 60%, indicating a significant inhibition of beet armyworm feeding. Furthermore, when beet armyworms consume food containing a certain concentration of tebuconazole, their growth and development are significantly restricted, and they may even die, demonstrating the sustained sub-lethal effect of tebuconazole on insect development. Moreover, tebuconazole is a plant-derived extract, making it green and safe, and suitable for long-term control of beet armyworm. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the effect of the present invention's thiabendazole on the growth and development of the beet armyworm;

[0015] Figure 2 This is a schematic diagram illustrating the effect of different concentrations of tebuconazole on the acetylcholinesterase activity in beet armyworm.

[0016] Figure 3 The present invention relates to septic acid EC. 50 Schematic diagram showing the effect of concentration on the activity of carboxylesterase in beet armyworm. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example:

[0018] Tabolic acid (TAB) (purchased from Wuhan Tianzhi Biotechnology Co., Ltd.) was used as the experimental compound material:

[0019] 1. An experiment was conducted to investigate the effects of feeding behavior on the third instar larvae of the beet armyworm:

[0020] (1) The test was conducted under the following conditions: relative humidity of 70%, experimental temperature of (26±1)℃, and photoperiod of (L12:D12).

[0021] After cleaning and drying the cabbage leaves, use a hole punch to create leaf discs with a diameter of 3 cm. Then, dissolve the compound in a 50% ethanol aqueous solution to prepare a specific concentration, and use the leaf immersion method to test the feeding behavior of beet armyworm larvae.

[0022] (2) Beet armyworms were fed cabbage leaves, and then 3rd instar larvae of similar size and weight were selected. They were starved for 8 hours and then subjected to a two-selection biological test: a leaf dish containing the test compound (T) was placed on the left and right sides of each petri dish; a larva was introduced into the center of a leaf dish (CK) soaked in deionized water. After 1 day, the details of the larvae feeding on the leaves were recorded: a transparent grid paper (1 mm) was placed on the grid paper. 2 Lay the leaves flat on a table, place them on top of grid paper, and trace the holes eaten by beet armyworm larvae with a pencil, calculating the area. Divide the same drug solution into groups of 15, with 3 parallel groups. Calculate the feeding rejection rate by the area of ​​the eaten leaves.

[0023] Refusal rate = (Leaf area consumed by control group - Leaf area consumed by treatment group) / (Leaf area consumed by control group + Leaf area consumed by treatment group) × 100%;

[0024] The specific results are shown in Table 1 below:

[0025] Table 1

[0026]

[0027] A significant feeding inhibition effect is defined as a feeding rejection rate of ≥60%. Therefore, a feeding rejection rate of 60.39% can be achieved at a concentration of 0.25 mg / mL, indicating that tebuconazole has a good feeding inhibition effect on beet armyworm at a relatively low concentration.

[0028] 2. Determination of the effect of sucralose on the growth and development of beet armyworm larvae:

[0029] The leaf immersion method was used, in which cabbage leaf dishes were completely immersed in thromboxane solutions of different concentration gradients for 30 seconds, then removed and air-dried in a clean bench until no obvious droplets remained on the surface before being placed in finger tubes. Third-instar beet armyworm larvae of uniform physiological condition were selected and subjected to 8 hours of starvation. Initial weight was measured and recorded for each larva using an electronic balance. Thirty third-instar beet armyworms were placed in finger tubes containing cabbage leaves immersed in different concentrations of the compound, with parallel control experiments conducted. The tube openings were covered with double layers of sterile gauze and sealed with rubber rings to ensure ventilation and prevent larval escape. Fresh leaf dishes were replaced every 24 hours after the start of treatment, and larval excrement was removed simultaneously. Weight changes of surviving larvae were measured at fixed time points. Three biological replicates were set up for each group; the dose-time effect of different concentrations of thromboxane on the growth and development of beet armyworm larvae was determined after 6 days of feeding.

[0030] Specific results are as follows Figure 1 As shown, feeding on different concentrations of tebuconazole leaves had varying effects on the body weight of the beet armyworm. With increasing concentration, the rate of weight gain in the beet armyworm decreased. When the tebuconazole concentration was 0.05 mg / mL, the growth rate of the beet armyworm slowed down over time, reaching a maximum inhibition rate of 35.24% on the sixth day. When the tebuconazole concentration was 0.25 mg / mL, the growth rate of the beet armyworm significantly slowed down over time, reaching an inhibition rate of 42.47% on the fourth day before beginning to decrease. This indicates that tebuconazole can inhibit the growth of beet armyworm larvae.

[0031] During the experiment, as beet armyworm larvae continuously fed on leaves containing tebuconazole solution, mortality occurred in the experimental group. The larvae in the experimental group showed significantly lower weight and some deformities compared to normally grown larvae. The results indicate that tebuconazole directly affects the growth and development of the beet armyworm, and that increasing concentration and treatment time leads to mortality.

[0032] 3. Test on the toxicity of sucralose to beet armyworm:

[0033] Following the above experiment, different concentrations of thiabendazole were used to conduct EC treatment on the beet armyworm. 50 The analysis results are shown in Table 2 below:

[0034] Table 2

[0035]

[0036] 4. Experiment on the effect of sucralose on enzyme activity in beet armyworm larvae:

[0037] 4.1 Determination of acetylcholinesterase activity in beet armyworm larvae:

[0038] (1) Enzyme solution preparation

[0039] The compound was prepared at specific concentrations, and each concentration was fed to fourth-instar larvae of the beet armyworm using the leaf-dip method. Ethanol was used as a control. Treatments were conducted at 24 h and 48 h. The selected larvae were cleaned in distilled water and air-dried. Each larva was then added to 0.1 mol / L pH 7.8 phosphate buffer, with each treatment repeated three times. The mixture was centrifuged at 8000g for 10 min at 4°C. The supernatant was collected and placed on ice as the test sample.

[0040] (2) Assay of acetylcholinesterase activity

[0041] Preheat the microplate reader for at least 30 minutes. Add reagents according to the kit instructions, mix well, and incubate for 2 minutes. Measure the absorbance at 412 nm and record it as Assay A and Control A. During the assay, place the sample and working solution on ice to prevent denaturation and inactivation.

[0042] Calculate the AchE activity of the sample according to the formula in the instruction manual:

[0043] AchE enzyme activity (U / g) = [ΔA ÷ (ε × d) × V colorimetric activity × 10] 9 ]÷(W×Vsample÷Vtotalsample×Vsupernatant÷Venzymecatalyst) ÷T=2255×ΔA÷W;

[0044] ΔA: A determination - A control; ε: TNB molar extinction coefficient, 13.6 × 10⁻⁶ 3 L / mol / cm; d: optical path length of the cuvette, 1 cm; Vdeveloped: total volume of the colorimetric reaction system, 0.2 mL = 2 × 102 -4 L; unit conversion factor, 1 mol = 1 × 10 9 nmol; Venzyme: total volume of enzyme reaction, 0.115 mL; Vsupernatant: volume of supernatant aspirated, 0.01 mL; Vtotal: volume of extract added, 1 mL; W: sample mass, g; Vsample: volume of sample added, 0.015 mL; T: reaction time, 5 min.

[0045] Specific results are as follows Figure 2As shown: Compared with the control, 24 h after drug administration (T24) in 3rd instar larvae of the beet armyworm, AChE activity showed a trend of first decreasing and then increasing with increasing taurenic acid concentration; when the TAB concentration was 0.01 mg / mL, AChE activity was inhibited compared with the control, with a decrease of 13.29%; when the concentration was increased to 0.1 mg / mL, AChE activity was activated compared with the control, with an increase of 1.94% in vivo. 48 h after drug administration (T48) in 3rd instar larvae of the beet armyworm, compared with the control, AChE activity showed a trend of first increasing and then decreasing with increasing concentration. When TAB was 0.01 mg / mL, AChE activity was inhibited compared to the control, with a decrease of 16.26%; when the concentration was increased to 0.1 mg / mL, AChE activity was still inhibited compared to the control, with a decrease of 5.65% in vivo; when the concentration was increased to 0.25 mg / mL, AChE activity was activated compared to the control, with an increase of 12.53% in vivo.

[0046] When the concentration of tebuconazole was 0.05 mg / mL, AChE activity was inhibited compared to the control, decreasing by 23.46%. When the concentrations of tebuconazole were 0.1 mg / mL and 0.25 mg / mL, AChE activity was activated compared to the control, but the difference was not significant. In third-instar larvae of the beet armyworm, AChE activity also showed a trend of initial inhibition followed by activation 48 h after drug administration. When the concentration of tebuconazole was 0.05 mg / mL, AChE activity was inhibited compared to the control, decreasing by 27.97%. When the concentration of tebuconazole was 0.25 mg / mL, AChE activity was activated compared to the control, increasing by 28.66%.

[0047] 4.2 Determination of carboxylesterase activity in beet armyworm larvae:

[0048] (1) Enzyme solution preparation

[0049] Using ethanol as a solvent, the compound was prepared to a concentration of EC. 50 Different concentrations of the pesticide were applied to the pronotum of 4th instar beet armyworm larvae, with 2 μL of each concentration as a control. After treatment, the larvae were placed in petri dishes containing fresh cabbage leaves. Live larvae were collected at 0 h, 2 h, 4 h, 6 h, 8 h, and 12 h after treatment to prepare the enzyme solution. The treated larvae were homogenized in 1 mL of 0.1 mol / L pH 7.8 phosphate buffer on ice. The supernatant was diluted 10-fold with distilled water and then processed according to the assay procedure. Each treatment was repeated three times, and centrifuged at 4000 g for 10 min at 4 ℃.

[0050] (2) Assay of carboxylesterase activity

[0051] Preheat the microplate reader for at least 30 minutes, add reagents according to the kit instructions, and measure the absorbance of the control group and treatment group at 450 nm for 10 seconds. Record these values ​​as A1 control and A1 measurement. Quickly place the microplate reader in a 37°C incubator for 5 minutes, and then quickly measure the absorbance at 5 minutes and 10 seconds. Record these values ​​as A2 control and A2 measurement.

[0052] Calculate the CarE activity of the sample according to the formula in the instruction manual:

[0053] CarE enzyme activity (U / g) = (ΔA test tube - ΔA blank tube) × V total ÷ 0.5 ÷ (W ÷ V total sample × V sample) ÷ T × F = 8 × (ΔA test tube - ΔA blank tube) × F;

[0054] Vsample total: Total volume of supernatant, 1 mL; Vsample: Volume of sample added, 0.01 mL; ΔAcontrol = A2 control - A1 control, ΔAdetermination = A2 determination - A1 determination; T: Reaction time, 5 min; W: Sample mass, g; Vreaction total: Total volume of reaction system, 0.2 mL; F: Dilution factor.

[0055] EC using TAB 50 Changes in CarE activity in the bodies of 3rd instar larvae of the beet armyworm after treatment with different concentrations are as follows: Figure 3 As shown in the figure, the results indicated that the activity of CarE in the third instar larvae of the beet armyworm was activated with increasing time after drug treatment. When the beet armyworm larvae fed on the drug-containing leaves immediately, the CarE activity in their bodies was activated compared with the control, with an increase of 49.29%; the maximum CarE activity was reached after 4 hours of TAB treatment, with an in vivo CarE activity of 50.38% (P < 0.05).

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The application of tebuconazole in the control of beet armyworm, characterized in that, The sucralose is used to limit the development of beet armyworm, kill beet armyworm, or inhibit beet armyworm feeding.

2. The application according to claim 1, characterized in that: The effective inhibitory concentration (EC) of the thiabendazole against the beet armyworm is [missing information]. 50 It is 0.067 mg / mL.

3. The application according to claim 1, characterized in that: The concentration of the thiabendazole was ≥0.25 mg / mL when it inhibited feeding by the beet armyworm.

4. The application according to claim 1, characterized in that: The application method involves dissolving thiabendazole in a solvent and then spraying it onto crops to control beet armyworm.

5. The application according to claim 4, characterized in that: The concentration of the thrombocytidine dissolved in the solvent is ≥0.05 mg / mL.

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