Application of cinnamyl aldehyde in prevention and treatment of agricultural pest macrosiphum avenae

Abstract

The invention is suitable for the technical field of pest control, and provides application of cinnamyl aldehyde in control of agricultural pest macrosiphum avenae. The application effect of the cinnamyl aldehyde in prevention and treatment of the agricultural pest sitobion avenae is defined, and the application effect is specifically shown as follows: in the action activity, the cinnamyl aldehyde has remarkable repelling, fumigating and contact killing effects on the sitobion avenae; on the influence of growth and development, the cinnamyl aldehyde treatment can significantly prolong the period and the earlier stage of reproduction of macrosiphum avenae, shorten the life of adults, the period of reproduction and the earlier stage of aphid production, reduce the amount of aphids produced by single female aphids, significantly reduce population parameters such as intrinsic growth rate, weekly limit growth rate and net value-added rate, effectively inhibit population growth, and improve the survival rate of macrosiphum avenae. Meanwhile, the macrosiphum avenae is abnormal in embryonic development, difficult in ecdysis, dead and malformation of winged aphids. In conclusion, the cinnamyl aldehyde has double effects of directly preventing and controlling the sitobion avenae and inhibiting population growth on the sitobion avenae, has the potential of being developed into a green pesticide due to high safety and low residue, and provides a new way for comprehensive treatment of the sitobion avenae.

Description

Technical Field

[0001] This invention belongs to the field of pest control technology, and in particular relates to the application of cinnamaldehyde in the control of the agricultural pest, wheat aphid. Background Technology

[0002] wheat aphid S. avenae *Fabricius* is an insect belonging to the order Hemiptera and the family Aphidoidea. The wheat aphid is the dominant aphid species in my country, causing damage in all wheat-growing areas. It primarily feeds on wheat sap using its piercing-sucking mouthparts, causing wheat grains to shrivel, reducing grain weight and number. It also transmits various plant viruses, including barley yellow dwarf virus. Due to its severe damage to wheat, it was included in the "List of Class I Crop Diseases and Pests (2023)" (Announcement No. 654 of the Ministry of Agriculture and Rural Affairs of the People's Republic of China) in 2023. The wheat aphid has a short generation cycle, high reproductive capacity, and migratory ability. Besides wheat, the wheat aphid also damages other gramineous plants such as barley, oats, and corn. In the past 10 years, the annual affected area of ​​wheat aphids in my country has exceeded 200 million mu (approximately 13.3 million hectares), accounting for about 57% of the total wheat planting area. Severe infestations can lead to wheat yield reductions of over 30%.

[0003] Currently, aphid control primarily relies on chemical control, supplemented by biological control. While chemical control is fast-acting, effective, and easy to implement, prolonged use of the same type of insecticide (such as neonicotinoids, pyrethroids, and organophosphates) in the same area leads to varying degrees of resistance in aphids, and even cross-resistance to several chemical pesticides. Since 2020, the resistance level of wheat aphids to flonicamid in many parts of my country has been rising year by year to medium to high levels; in 2023-2024, the population of cereal aphids in many regions of my country developed medium to high levels of resistance to pyrethroid pesticides. Increased aphid resistance not only increases control costs but also leads to pest resurgence, pesticide residues, and other environmental problems. Furthermore, chemical pesticides are toxic to humans, affecting human health, and their high residue and slow degradation characteristics pollute the air and soil, harming plants, animals, beneficial soil microorganisms, insects, and other non-target organisms. Long-term and extensive use results in prominent "3R" problems (resistance, resurgence, and residues). Therefore, there is an urgent need to find green pesticides that are low in toxicity, low in residue, and highly effective.

[0004] Plant essential oils are complex mixtures containing various volatile components, possessing a variety of biological activities such as repellency, stomach poisoning, contact killing, attraction, antifeedant effects, and inhibition of pest growth and development. They are the preferred lead compounds for new pesticide development. Through multiple mechanisms and targets, including regulating intestinal disruption, pest growth, and pest metabolism, they synergistically act on insects. Compared to chemical pesticides, they are safer, greener, more efficient, and less toxic, and hold promise for widespread replacement of chemical pesticides. Cinnamaldehyde, a major component of cinnamon essential oil, exhibits high safety for mammals and non-target organisms and is commonly used as a food and cosmetic additive. It also features high volatility and low residue levels. Numerous studies have shown that it possesses various biological activities, including antibacterial, antioxidant, anticancer, analgesic, anti-inflammatory, insecticidal, and preservative effects, playing a crucial role in the biological control of agricultural pests, sanitary pests, and stored grain pests.

[0005] In response to the current situation of high toxicity, high residue of chemical pesticides and the increasing resistance of pests, this invention proposes the application of cinnamaldehyde in the control of the agricultural pest, wheat aphid. Summary of the Invention

[0006] The purpose of this invention is to provide the application of cinnamaldehyde in the control of the agricultural pest wheat aphid, aiming to solve the problems mentioned in the background art.

[0007] The objective of this invention is achieved through the following technical solution: The application of cinnamaldehyde in the control of the agricultural pest, wheat aphid, including its repellent, fumigation, and contact effects on the wheat aphid.

[0008] Furthermore, the control measures include repellent, fumigation, and contact action against wheat aphids.

[0009] Furthermore, in the repellent effect, the concentration of cinnamaldehyde is 1.5 μL / mL to 6.0 μL / mL; in the fumigation effect, the LC50 of cinnamaldehyde is... 50 The concentration was 2.5481 μL / mL; in the contact toxicity assay, the LC50 of cinnamaldehyde was... 50 It is 0.1056 uL / mL.

[0010] Furthermore, the control measures also include suppressing the population growth of the wheat aphid by affecting its growth and development.

[0011] Furthermore, the factors affecting the growth and development of the wheat aphid include at least one of prolonging the nymphal lifespan, shortening the adult lifespan, shortening the reproductive lifespan, reducing the number of aphids laid by a single female, shortening the pre-aphid stage, and prolonging the pre-reproductive stage.

[0012] Furthermore, the aforementioned impact on the growth and development of the wheat aphid specifically manifests as abnormal embryonic development, difficulty in molting, or malformation of winged aphids.

[0013] An insecticide for controlling wheat aphids, wherein the active ingredient of the insecticide is cinnamaldehyde, and it also contains a co-solvent, wherein the co-solvent is a 0.1% Tween 80 aqueous solution or acetone, wherein the 0.1% Tween 80 aqueous solution is used to prepare cinnamaldehyde into a microemulsion to achieve a repellent or fumigation effect, and acetone is used to prepare cinnamaldehyde into a film to achieve a contact killing effect.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention clarifies the application effect of cinnamaldehyde in controlling the agricultural pest, the wheat aphid. Specifically, in terms of activity, cinnamaldehyde has significant repellent, fumigation, and contact-killing effects on the wheat aphid. Regarding its impact on growth and development, cinnamaldehyde treatment significantly prolongs the nymphal and pre-reproductive stages of the wheat aphid, shortens the adult lifespan, reproductive period, and pre-laying stage, reduces the number of aphids laid per female, and significantly decreases population parameters such as intrinsic growth rate, weekly growth rate, and net growth rate, effectively inhibiting population growth. It also leads to abnormal embryonic development, molting difficulties and death, and malformation in winged aphids. In summary, cinnamaldehyde has a dual effect of direct control and population inhibition against the wheat aphid. Furthermore, due to its high safety and low residue, it has the potential to be developed into a green pesticide, providing a new approach for the integrated management of the wheat aphid. Attached Figure Description

[0015] Figure 1 The population dynamics of wheat aphids under cinnamaldehyde treatment and control (CK) for 60 days.

[0016] Figure 2 The abnormal phenotypes of wheat aphid after cinnamaldehyde treatment are shown in the following: a) wheat aphid embryos cannot develop normally into nymphs due to cinnamaldehyde treatment; b) wheat aphids die due to difficulty in molting after cinnamaldehyde treatment; and c) winged aphid deformities after cinnamaldehyde treatment. Detailed Implementation

[0017] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the technical solution of this invention is described in detail below, but this should not be construed as limiting the scope of implementation of this invention. In this invention, materials, reagents, or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0018] The tested aphids: Wheat aphids were collected in 2024 from the Hefei Academy of Agricultural Sciences in Anhui Province (31°49′21.30″N, 117°13′18.25″E). They were continuously reared for multiple generations in breeding cages in a greenhouse in Beijing, and the breeding conditions were maintained at 20±1℃, 60%~80% humidity, and a light:dark ratio of 16h:8h. The wheat variety used as food was the aphid-susceptible Zhongmai 175.

[0019] Test reagent: Cinnamaldehyde (98%) was purchased from Anhui Zesheng Anaiji Reagent Co., Ltd.

[0020] To develop a low-toxicity, highly efficient, safe, pollution-free, and broad-spectrum plant-derived insecticide, this invention clarified the bioactivity of cinnamaldehyde against the major agricultural pest, the wheat aphid, and observed its effects on the aphid's growth and development. Specifically, when determining the fumigation and repellency effects of cinnamaldehyde on the wheat aphid and its growth and development, a microemulsion of cinnamaldehyde was prepared using 0.1% Tween 80 as a co-solvent under magnetic stirring. For the contact toxicity test, cinnamaldehyde was dissolved in acetone. The morphology of the wheat aphid was observed and photographed using a Nikon SMZ18 stereomicroscope. The impact on its growth and development was assessed using sex life table software, analyzing key parameters of the wheat aphid's growth and development and population changes at sublethal concentrations.

[0021] Example 1: Repellency Experiment; Experimental Methods: The repellency effect in a closed environment was determined using a Y-type olfactometer. Cinnamaldehyde was prepared as a microemulsion using a 0.1% Tween 80 aqueous solution with a magnetic stirrer, and diluted to concentrations of 6, 3, 1.5, 0.75, and 0.375 μL / mL. A 0.1% Tween 80 aqueous solution served as a control. The Y-type olfactometer had a main arm length of 10 cm, an inner diameter of 2.5 cm, and two side arms of 15 cm each, with an angle of 75° between the sidewalls. Before the experiment, the Y-type olfactometer was thoroughly cleaned with 75% anhydrous ethanol and dried to remove residual odors and other impurities. After connecting the atmospheric sampler to the Y-type tube, the atmospheric sampler was turned on, and the flow rate was adjusted to 100 mL / min. Cut filter paper into uniform shapes. Using a pipette, 200 μL of the control group solution and 200 μL of the treatment group solution were placed on opposite sides of a Y-shaped tube. Untreated wheat seedlings were then placed on either side for feeding. Each experimental replicate required the release of 30 adult wheat aphids. The repellency rate was recorded 24 hours after the start of the experiment. Three biological replicates were performed for each concentration. The entire experiment was conducted under dark conditions.

[0022] The avoidance activity is graded according to the avoidance rate: Grade 0, 0.01%~0.1%; Grade I, 0.1%~20%; Grade II, 20.01%~40%; Grade III, 40.1%~60%; Grade IV, 60.1%~80%; Grade V, 80.1%~100%.

[0023] The results are shown in Table 1: Table 1: Repellent effect of cinnamaldehyde on wheat aphid in a closed environment (mean ± standard error)

[0024] Note: Different lowercase letters indicate significant differences in repellency between different concentrations of the same essential oil (cinnamaldehyde) (P<0.05).

[0025] As shown in Table 1, the repellency rates of cinnamaldehyde at concentrations of 6, 3, and 1.5 μL / mL under closed conditions were 91.1%, 84.4%, and 75.6%, respectively, corresponding to levels V, V, and IV. There were no significant differences among these three concentrations. The repellency effect gradually decreased with decreasing concentration. At a cinnamaldehyde concentration of 0.75 μL / mL, the repellency rate under closed conditions was 24.4%, corresponding to level II. At a cinnamaldehyde concentration of 0.375 μL / mL, there was no repellency effect under closed conditions; instead, it exhibited attraction.

[0026] Example 2: Fumigation effect experiment; Experimental Methods: Fumigation activity was determined using a wide-mouth bottle sealed fumigation method. Cinnamaldehyde was prepared as a microemulsion using a 0.1% Tween 80 aqueous solution with a magnetic stirrer. The microemulsion was diluted to concentrations of 10, 5, 2.5, 1.25, and 0.625 μL / mL, with a 0.1% Tween 80 aqueous solution serving as a control. Wingless aphids (≥25 individuals) were collected in a wide-mouth bottle. 50 μL of the microemulsion was pipetted onto 2 cm × 2 cm filter paper, which was then suspended inside the bottle. Each treatment was repeated in triplicate, and mortality was recorded after 24 hours.

[0027] The results are shown in Tables 2 and 3: Table 2: Fumigation toxicity equation of cinnamaldehyde against wheat aphid

[0028] Table 3: Fumigation effect of cinnamaldehyde on wheat aphid (mean ± relative standard deviation)

[0029] Note: Different lowercase letters indicate significant differences in repellency between different concentrations of the same essential oil (cinnamaldehyde) (P<0.05).

[0030] As shown in Tables 2 and 3, the LC50 of cinnamaldehyde against the wheat aphid was determined by analyzing the regression line of the fumigation effect. 50 The concentration was 2.5481 uL / mL. Furthermore, at the highest concentration of 10 uL / mL, cinnamaldehyde achieved a fumigation mortality rate of 97.01% against the wheat aphid.

[0031] Example 3: Contact killing experiment; Experimental Methods: Contact toxicity was determined using the film-film method. Acetone was used as a co-solvent and control. Cinnamaldehyde was dissolved in acetone to prepare five concentrations: 0.25, 0.20, 0.15, 0.10, and 0.05 μL / mL. 150 μL of the solution (i.e., the cinnamaldehyde acetone solution) was added to a glass tube (1.5 cm in diameter and 6 cm in height) using a micropipette. The glass tube was placed on a roller mixer for 2 hours to allow the acetone to evaporate and the cinnamaldehyde to form a film and be uniformly adsorbed inside the glass tube. The entire experiment was conducted in a fume hood. Each treatment was repeated in triplicate. Wingless aphids (≥25 individuals) were collected and placed in the glass tube. Mortality was recorded after 3 hours.

[0032] The results are shown in Tables 4 and 5: Table 4: Contact toxicity equation of cinnamaldehyde against wheat aphid

[0033] Table 5: Contact toxicity of cinnamaldehyde against wheat aphid (mean ± relative standard deviation)

[0034] Note: Different lowercase letters indicate significant differences in repellency between different concentrations of the same essential oil (cinnamaldehyde) (P<0.05).

[0035] Data from Tables 4 and 5 show that cinnamaldehyde has contact toxicity against the wheat aphid, and the LC-15 toxicity curves show... 50 It is 0.1056 uL / mL.

[0036] Example 4: Life table experiment; Experimental Methods: Cinnamaldehyde was prepared into a microemulsion using a 0.1% Tween 80 aqueous solution with a magnetic stirrer. The microemulsion was diluted to five concentration gradients: 6.000, 3.000, 1.500, 0.750, and 0.375 μL / mL. A 0.1% Tween 80 aqueous solution was used as a control. The toxicity was determined using the insect-leaf immersion method to ascertain the sublethal concentration. Based on the toxicity test results, the sublethal concentration (LC50) was determined. 30 The optimal experimental concentration was determined. Subsequently, cinnamaldehyde was prepared to a concentration of LC using a 0.1% Tween 80 aqueous solution. 30Microemulsions were used to raise first-instar aphids to adulthood. The adults were then treated with the microemulsion, and their first-instar nymphs were raised individually in 130 dishes. Hydroponic wheat seedlings (3-4 cm in length) were immersed in the microemulsion for 1 minute, then dried for the aphids to feed on. Observations were conducted daily, and the treated seedlings were replaced every two days. Molting and maturation times of nymphs were recorded. After maturity, the number of aphids laid was recorded, and nymphs were removed until the adults died. A sex life table for specific ages was established to calculate the duration, survival rate, and number of aphids laid per female of the wheat aphid at each developmental stage. A control group and a cinnamaldehyde-treated group were included in the experiment. Data were calculated using the age-instar sex life table proposed by Chi and Liu, while ignoring factors such as disease, predation, and parasitism. The TIMING-MSChart was used to predict the population dynamics of the wheat aphid (130 individuals / group) 60 days after cinnamaldehyde interference.

[0037] result: (1) Effects of cinnamaldehyde on growth and development factors related to wheat aphid; Table 6: Effects of cinnamaldehyde on the developmental stages of the wheat aphid

[0038] Note: The data in the table are mean ± standard error; different letters after the data in the same row indicate significant differences (P<0.05, paired repeated sampling).

[0039] Table 7: Effects of cinnamaldehyde on life table parameters of wheat aphid populations

[0040] Note: The data in the table are mean ± standard error; different letters after the data in the same row indicate significant differences (P<0.05, paired repeated sampling).

[0041] As shown in Table 6, the wheat aphid treated with cinnamaldehyde was able to complete its generation cycle, but its nymphal lifespan was significantly longer than that of the control group; the adult lifespan, reproductive lifespan, number of aphids per female, and pre-aphid production period were significantly shortened; and the pre-reproductive period was significantly prolonged.

[0042] The data in Table 7 show the intrinsic growth rate of wheat aphids after cinnamaldehyde treatment. r The net increase rate decreased by 0.10 compared to the control group. R 0 Decrease of 10.29, weekly growth rate λ The decrease of 0.10 was statistically significant (P<0.05). Furthermore, compared to the control group, the average generation cycle of the cinnamaldehyde-treated group was prolonged by 0.09 days, but this was not statistically significant (P>0.05). This indicates that the wheat aphid has paid a certain fitness cost to adapt to the cinnamaldehyde environment.

[0043] Population prediction of the wheat aphid was performed based on age-instar sex life table data. The results showed that ( Figure 1 Cinnamaldehyde treatment effectively suppressed the population growth of the wheat aphid. The population growth rate of the wheat aphid treated with cinnamaldehyde was low, with a predicted population size of approximately 490 individuals at 60 days, while the predicted population size of the control group was approximately 80,000 individuals at 60 days.

[0044] (2) Changes in the phenotype of the wheat aphid after treatment with cinnamaldehyde; During the observation process, it was found that cinnamaldehyde treatment caused the embryos of the wheat aphid to fail to develop normally into nymphs. Figure 2 a) Difficulty in molting leading to death ( Figure 2 (b) and winged aphid deformities ( Figure 2 c) and other similar situations.

[0045] in conclusion: This invention demonstrates that cinnamaldehyde has repellent, fumigation, and contact-killing effects on the agricultural pest, the wheat aphid. Treatment with cinnamaldehyde adversely affects the growth and development of the wheat aphid, reducing its survival and reproductive rates, decreasing its population size, preventing embryos from developing into nymphs, causing molting difficulties, and resulting in morphological abnormalities (especially wing deformities in winged aphids). Therefore, cinnamaldehyde has the potential to be developed into a green pesticide, opening up new possibilities for the integrated management of the wheat aphid and its potential for control.

[0046] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. The application of cinnamaldehyde in the control of the agricultural pest wheat aphid, characterized in that, The control measures include repellent, fumigation, and contact toxicity against wheat aphids.

2. The application according to claim 1, characterized in that, In the repellent effect, the concentration of cinnamaldehyde is 1.5 μL / mL to 6.0 μL / mL; in the fumigation effect, the LC50 of cinnamaldehyde is... 50 The concentration was 2.5481 μL / mL; in the contact toxicity assay, the LC50 of cinnamaldehyde was... 50 It is 0.1056 uL / mL.

3. The application according to claim 1, characterized in that, The control measures also include suppressing the population growth of the wheat aphid by affecting its growth and development.

4. The application according to claim 3, characterized in that, The effects on the growth and development of the wheat aphid include at least one of the following: prolonging the nymphal lifespan, shortening the adult lifespan, shortening the reproductive lifespan, reducing the number of aphids laid by a single female, shortening the pre-aphid-laying stage, and prolonging the pre-reproductive stage.

5. The application according to claim 3, characterized in that, The specific manifestations of the impact on the growth and development of the wheat aphid are that it leads to abnormal embryonic development, difficulty in molting, or deformities in winged aphids.

6. An insecticide for controlling wheat aphids, characterized in that, The active ingredient of the insecticide is cinnamaldehyde, and it also contains a co-solvent, which is a 0.1% Tween 80 aqueous solution or acetone. The 0.1% Tween 80 aqueous solution is used to prepare cinnamaldehyde into a microemulsion to achieve a repellent or fumigation effect, and acetone is used to prepare cinnamaldehyde into a film to achieve a contact killing effect.

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