Use of citric acid or capric acid in improving flight ability of irradiated sterile codling moth males

Abstract

The application belongs to the field of insect breeding, and specifically discloses application of citric acid or capric acid in improving flight ability of irradiated sterile male codling moth, wherein the codling moth is fed with a sucrose solution containing 4 mM citric acid or a sucrose solution containing 250 mu M capric acid within 24 hours after the irradiated male codling moth emerges from the cocoon. Compared with the prior art, the application proves that the feeding treatment of citric acid or capric acid can improve the flight ability of the irradiated sterile male codling moth, and further improve the mating success rate of the sterile male codling moth and the control effect on the population.

Description

Technical Field

[0001] This invention relates to the field of insect breeding, particularly the application of citric acid or decanoic acid in improving the flight ability of irradiated sterile male codling moths. Background Technology

[0002] Sterile insect technique (SIT) is an important component of integrated pest management for large-scale pest control. This technique involves releasing large quantities of sterile males of target pests into the control area, causing them to mate with wild females and produce sterile offspring, thereby gradually suppressing the target pest population. Insect flight plays a crucial role in various activities such as courtship, foraging, and migration. Previous studies have shown that exposure to X-rays, even at optimal doses, negatively impacts the flight ability of the codling moth (Cydiapomonella), directly affecting the dispersal distance and courtship and mating success rates of sterile insects in the field.

[0003] Energy metabolism is the primary energy source for insect flight. Citric acid is an important intermediate metabolite in the tricarboxylic acid (TCA) cycle, and a metabolite of citrate synthase, the first key rate-limiting enzyme in the TCA cycle, thus determining the entire TCA cycle's progress. Decanoic acid is an activator of citrate synthase, which can activate citrate synthase to produce citrate, thereby activating or initiating the TCA cycle. Studies have shown that environmental pollution leads to cadmium accumulation in plants, and the flight ability of codling moths is impaired after feeding on plant nectar. Exogenous supplementation with citric acid or decanic acid can partially restore the flight ability of codling moths under cadmium stress, which is beneficial for their pollination of a wider range of plants in the field. However, it remains unclear whether feeding with citric acid or decanic acid can improve the flight ability of irradiated sterile male codling moths, thereby increasing their dispersal distance and courtship and mating success rates in the field. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides the application of citric acid or decanoic acid in enhancing the flight ability of irradiated sterile male codling moths.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0006] The application of citric acid or decanoic acid in improving the flight ability of irradiated sterile male codling moths: Within 24 hours after the emergence of male codling moths irradiated by X-rays, the codling moths were fed a sucrose solution with a concentration of 4 mM citric acid or a sucrose solution with a concentration of 250 μM decanoic acid for 48 hours.

[0007] Furthermore, the irradiation is performed using X-rays at a dose of 200 Gy.

[0008] Compared with existing technologies, this invention demonstrates that feeding treatment with citric acid or decanoic acid can improve the flight ability of irradiated sterile male codling moths, thereby increasing the mating success rate of sterile male codling moths and the control effect on the population. Attached Figure Description

[0009] Figure 1 Effects of citric acid or decanoic acid feeding treatments on energy metabolism in male codling moths: (a) Citric acid content in male codling moths after exogenous decanoic acid supplementation; (b) CS2 expression level in male codling moths after exogenous decanoic acid supplementation; (c) CS activity in male codling moths after exogenous decanoic acid supplementation; (d) ATP content in male codling moths after exogenous decanoic acid supplementation; (e) ATP content in male codling moths after exogenous citric acid supplementation.

[0010] Figure 2 Effects of citric acid or decanoic acid feeding treatments on the flight performance of male codling moths: (a) Effects of feeding treatments with 4 mM citric acid solution and 250 μM decanoic acid solution on the maximum flight speed of male codling moths; (b) Effects of feeding treatments with 4 mM citric acid solution and 250 μM decanoic acid solution on the average flight speed of male codling moths; (c) Effects of exogenous citric acid or decanoic acid supplementation on the flight time of male codling moths; (d) Effects of exogenous citric acid or decanoic acid supplementation on the flight distance of male codling moths. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0012] Unless otherwise specified, all raw materials and reagents used in the following examples were commercially available; disposable plastic cup (320mL); citric acid (Beijing Solarbio Science & Technology Co., Ltd., Beijing, China); decanoic acid (Beijing Solarbio Science & Technology Co., Ltd., Beijing, China); disposable transparent plastic box (1500mL); sulfuric acid paper; shower cap; petri dish; bottle cap; hot melt adhesive; 502 glue; ice box.

[0013] Sources, artificial rearing methods, and rearing conditions of the codling moth:

[0014] 1. Rearing methods for the test insects

[0015] The insects used in the test were donated by the Institute of Plant Protection, Chinese Academy of Agricultural Sciences, and the Agricultural Invasive Biological Control Detection Laboratory. They were raised for more than 70 generations in the Insect Toxicology Laboratory of Shenyang Agricultural University, without being treated with pesticides or other radiation.

[0016] 2. Feeding conditions

[0017] The photoperiod is 8 hours in the dark and 16 hours in the light, with a temperature of 26±1℃ and a relative humidity of 60%~70%.

[0018] 3. Feeding methods

[0019] Artificial feed formulation: See patent application number: 201910839547.3. This feed is prepared from the following raw materials in the following mass ratios: soybean flour 4-8%, corn flour 4-8%, sucrose 1-3%, yeast powder 2-4%, dried apple powder 1.2-2%, ascorbic acid 0.2-0.5%, methylparaben 0.15-0.4%, sorbic acid 0.05-0.2%, cholesterol 0.01-0.03%, tomato paste 16-18%, agar 1-1.4%, and water 54.47%-71.59%.

[0020] Larval rearing method: Collect the egg paper from the top of the egg-laying box every day and place the egg paper in an artificial climate chamber. After the eggs hatch, pick up the newly hatched larvae with a paintbrush and gently place them on the surface of the artificial feed for codling moths. Reare them until the late 5th instar larvae stage.

[0021] Rearing of Pupae and Adults: Prepare a disposable transparent plastic box. Line the bottom of the box with multiple layers of paper towels. Pick out the 5th instar larvae from the centrifuge tubes and place them in the box. After they pupate in the box, check the pupation status daily. Place pupae from the same day into a petri dish, distinguishing between males and females based on their morphological characteristics, and label the pupation date. Before the adults emerge, cut a 5cm*4cm square hole on each side of the disposable transparent plastic box. Apply hot melt glue evenly to the bottom of the box around the perimeter. Extend the shower cap and stick it inside the box, covering the top of the box with the shower cap. Attach a bottle cap to the center of the bottom of the box. Place a piece of cotton soaked in 10% honey water inside the bottle cap. Place the pupae before emergence into the rearing box. Fold tracings of parchment paper into 3cm*2cm grids and cover the top of the box as a medium for collecting eggs. Place the box cap on top of the parchment paper and secure it with a rubber band. Add 10% honey water every 2 days and change the egg paper every 1-2 days.

[0022] Example 1: Effects of citric acid or decanoic acid feeding treatments on energy metabolism in sterile male codling moths.

[0023] The specific procedure is as follows: Within 24 hours of emergence of male codling moths exposed to X-rays, they were fed a sucrose solution containing 4 mM citric acid for 48 hours. A 100 mM decanoic acid stock solution was dissolved in DMSO to prepare a decanoic acid supplement. Within 24 hours, the codling moths were randomly divided into three groups: a control group (0 + DMSO group), an X-ray irradiation group (200 Gy + DMSO group), and a decanoic acid supplement group (200 Gy + decanoic acid group). The control group was fed a sucrose solution supplemented with DMSO. In the 200 Gy X-ray irradiation group, 100 mM of the decanoic acid supplement was added to the sucrose solution, bringing the final concentration of decanoic acid in the sucrose solution to 250 μM. These nutrient solutions were used to feed the codling moths for 48 hours.

[0024] Prepare several 320mL disposable plastic cups. Place the sterile male codling moths that have emerged 24 hours ago into the disposable transparent plastic cups. Then, drip 4mM citric acid solution or 250μM decanoic acid solution onto the bottom of the plastic cups. After feeding for 48 hours, remove the moths and perform citric acid content determination, ATP content determination, citrate synthase (CS) activity determination, and expression level determination of the key gene CS2 encoding citrate synthase.

[0025] Data processing employed t-tests for significance analysis. Experimental results are expressed as mean ± standard error, and plotted using Graphpad Prism 5 software. The effects of citric acid or decanoic acid feeding treatments on the energy metabolism of sterile male codling moths were investigated. Figure 1 As shown.

[0026] Depend on Figure 1 As shown in (a), exogenous supplementation of decanoic acid can raise the citric acid content in sterile male codling moths to normal levels; Figure 1 As shown in (b), exogenous supplementation with decanoic acid significantly increased the CS2 expression level in sterile male codling moths; Figure 1 As shown in (c), exogenous supplementation of decanoic acid can increase the CS activity in sterile male codling moths to normal levels; Figure 1 As shown in (d), exogenous supplementation of decanoic acid can raise the ATP content in sterile male codling moths to normal levels; Figure 1 As shown in (e), exogenous citric acid supplementation can increase the ATP content in sterile male codling moths to normal levels. In conclusion, citric acid or decanoic acid feeding treatment affects the energy metabolism of sterile male codling moths.

[0027] Example 2: Effects of citric acid or decanoic acid feeding treatment on the flight performance of sterile male codling moths.

[0028] Flight performance was statistically analyzed using the FXMD-24-USB insect flight information system. The effects of citric acid or decanoic acid feeding treatments on the flight performance of sterile male codling moths were investigated. Figure 2 As shown.

[0029] Depend on Figure 2 (a) Figure 2 As shown in (b), feeding treatments with 4 mM citric acid solution and 250 μM decanoic acid solution had no effect on the maximum or average flight speed of sterile male codling moths; Figure 2 As shown in (c), the flight time of male codling moths supplemented with exogenous citric acid or decanoic acid was significantly increased compared to untreated male codling moths, and almost identical to that of untreated male codling moths. Figure 2 As shown in (d), the flight distance of male codling moths supplemented with exogenous citric acid or decanoic acid was significantly increased compared with that of untreated male codling moths under irradiation, and was almost consistent with that of untreated male codling moths.

[0030] This invention confirms that feeding treatment with citric acid or decanoic acid can improve the flight ability of irradiated sterile male codling moths, thereby increasing the mating success rate of sterile male codling moths and the control effect on the population.

[0031] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. The application of citric acid or decanoic acid in improving the flight ability of irradiated sterile male codling moths, characterized in that, Within 24 hours of emergence of male codling moths exposed to X-rays, the moths were fed a sucrose solution containing 4 mM citric acid or a sucrose solution containing 250 μM decanoic acid for 48 hours; the irradiation was performed using X-rays at a dose of 200 Gy.

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