A plant-derived mating disruptor for the gray tea geometrid moth

Abstract

This invention relates to a plant-derived mating disruptor for the tea geometrid moth. The composition and weight ratio of the disruptor are: decanal: dodecanal: limonene = 4-6 parts: 4-6 parts: 0.8-1.2 parts. This invention screens plant volatile components that can interfere with the mating behavior of the tea geometrid moth, and obtains the optimal component ratio with good interference performance through formulation optimization experiments. This disruptor is environmentally friendly and has high control efficiency, and can be used for the control of the tea geometrid moth in tea gardens. Two consecutive years of field trials have shown that a slow-release dose of 2.6 mL m⁻² can reduce the tea geometrid moth population in tea gardens by more than 70%, and achieve a sustained pest control effect.

Description

Technical Field

[0001] This invention relates to a plant-derived mating disruptor for the gray tea geometrid moth, belonging to the field of crop plant protection. Background Technology

[0002] The grey tea looper (Ectropis grisescens Warren), belonging to the family Geometridae in the order Lepidoptera, is an important chewing pest of tea trees in my country. It is widely distributed and occurs in all tea-producing regions of my country, with particularly severe infestations in Hubei, Hunan, Jiangxi, and Zhejiang provinces. During outbreaks, tea trees can be devastated in a short time, leaving only old branches, turning the entire tea garden into a burnt state, resulting in total crop failure or even the death of the trees.

[0003] Currently, green control technologies for the tea looper mainly include sex pheromone trapping and migratory trapping, and nucleopolyhedrovirus (NPUV) preparations. However, sex pheromone trapping and migratory trapping technologies suffer from high costs and cumbersome replacement of sticky traps, while NPUV preparations have drawbacks such as complex preservation and breeding methods. Plant-derived odor substances are a class of natural volatile secondary metabolites extracted from plants and are currently mostly used to develop looper repellents. For example, patent CN113180067A discloses a method for repelling and controlling the tea looper using plant essential oils. The formula is based on a mass ratio of garlic essential oil: cypress essential oil: peppermint essential oil: chili essential oil = 5:2:2:1. During the larval outbreak period, it is diluted 100-750 times and sprayed on tea tree leaves, achieving pest control within 1 day. However, after being repelled, the pests continue to cause damage in surrounding fields, and the effectiveness of the repellent decreases significantly when the insect population density is high. In addition, spraying plant odor substances directly onto tea leaves not only causes them to evaporate quickly and have a short duration of effect, but may also affect the quality of the tea.

[0004] This invention utilizes plant-derived odor substances to interfere with the olfactory localization of male tea looper moths to females, disrupting mating and reducing the number of viable eggs produced by females, thus fundamentally reducing the looper moth population. Simultaneously, this invention employs a slow-release bottle as the application carrier, avoiding direct contact between the active ingredient and tea leaves, ensuring application safety while effectively extending the insecticidal effect. This invention's tea looper mating disruptor provides the plant insecticide market with a highly efficient, environmentally friendly product, meeting the new demands of the agricultural market. Summary of the Invention

[0005] The purpose of this invention is to provide a plant-derived mating disruptor for the tea geometrid moth. This invention screens plant volatile components that can interfere with the tea geometrid moth's courtship and mating behavior, and through formulation optimization experiments, obtains the optimal component ratio with good interference performance. This disruptor is environmentally friendly, highly efficient, and can be used for the control of the tea geometrid moth in tea gardens.

[0006] The technical solution of this invention is as follows: A mating disruptor derived from the plant *Tea geometrid moth*, wherein the composition and weight ratio of the mating disruptor are: decanal: dodecylaldehyde: limonene = 4-6 parts: 4-6 parts: 0.8-1.2 parts.

[0007] As a preferred embodiment of the present invention, the mating interference agent has the following composition and weight ratio: decanal: dodecylal: limonene = 5:5:1.

[0008] The mating interference agent of this invention achieves the best control effect. The pharmacological characteristics and functions of each component are as follows: Decanal is the main active substance in the formula that interferes with the mating of the tea geometrid moth; Dodecylaldehyde has the effect of interfering with the mating of the tea geometrid moth, and at the same time, its high boiling point can slow down the overall volatilization rate of the formula, thereby improving the residual effect of the formula; Limonene has the effect of interfering with the mating of the tea geometrid moth, reducing the drug resistance of the tea geometrid moth, and enhancing the stability of the formula.

[0009] The preparation process of the mating interference agent derived from the plant of the tea geometrid moth of the present invention is as follows: the three components of decanal, dodecylaldehyde and limonene are mixed in a ratio of 5:5:1, the mixture is injected into a 2 mL polypropylene (PP) slow-release bottle, the bottle mouth is heat-sealed, and the mixture is left to stand at room temperature for 48 h to obtain the mating interference agent.

[0010] To further illustrate the inventiveness of the plant-derived mating disruptor derived from the tea geometrid moth of the present invention, some experimental results of the screening process for the optimal formulation of the present invention are presented and explained here.

[0011] 1.1 Screening of active plant volatile components that interfere with mating of the tea geometrid moth 1.1.1 Experimental Methods From March to June 2022 and from June to August 2023, two experiments were conducted in Xian'an District, Xianning City, and Tuguan'ya Town, Danjiangkou City, Hubei Province, respectively, to screen for components that interfere with the mating activity of male inchworm moths. The experimental method involved using γ-terpinene, camphor, verbenone, benzyl nitrile, linalool, myrcene, phenol, borneol, 1,8-cineole, perillene, perilla aldehyde, lemonol, β-citronellol, geranial, geraniol, cinnamaldehyde, eugenol, anethole, cuminaldehyde, and cumin... Thirty-one plant volatile components, including alcohol, α-pinene, limonene, p-cymene, rosoxide, pentanal, heptanal, octanal, nonanal, decanal, dodecanal, and γ-undecalactone, were prepared into slow-release bottles. These bottles were then attached to a pheromone trap for the tea geometrid moth. The influence of each component's odor on the trap's trapping efficiency was investigated to screen for volatile components that interfere with the tea geometrid moth's mating behavior.

[0012] 1.1.2 Experimental Results The results showed that the three components, decanal, dodecanal, and limonene, could reduce the attraction rate of sex pheromones to the tea geometrid moth by more than 95% (see instruction manual). Figure 1 , 2 ).

[0013] 1.2 Optimization of the formulation of plant-derived mating disruptors for the tea geometrid moth 1.2.1 Experimental Methods The method of adding items one by one is adopted and carried out in two stages.

[0014] ①Using the single substance decanal, which had the best effect, as an effective control, dodecylaldehyde was added to decanal at ratios of 1:1, 10:1, and 50:1. The ratio of the two components with the best effect was selected through experiments.

[0015] ②Use the best-performing two-component mixture as an effective control, and continue to add limonene to the two-component mixture at this ratio (if the decanal single component is the best, add it to the decanal single component), adding it at (decanal + dodecylaldehyde): limonene = 1:1, 10:1, 50:1. Through experiments, select the ratio of the three components with the best effect, and finally determine the interferon formula.

[0016] 1.2.2 Experimental Results The results showed that when the compound ratio was decanal:dodecanoal = 1:1, the interference effect of the mixture on the mating behavior of the tea geometrid moth was significantly higher than that of the decanal single component (see the instruction manual appendix). Figure 3 a). When the compound ratio is (decanal + dodecanoal):limonene = 10:1 (where decanal: dodecanoal = 1:1), the interference effect of the mixture on mating of the tea geometrid moth is not significantly different from that of decanal: dodecanoal = 1:1 (see the instruction manual appendix). Figure 3 b). Considering that the ternary formulation has a more stable interference effect on insects and is less likely to induce drug resistance, the final formulation was chosen as decanal: dodecylal: limonene = 5:5:1.

[0017] The beneficial effects of the plant-derived mating disruptor derived from the tea geometrid moth of this invention: Compared with existing technologies, the advantages of this mating disruptor can be summarized in detail from aspects such as product quality, the inventive concept of the mating disruptor formulation, natural pesticide residue-free properties, and insecticidal efficiency. Plant-derived odor substances are a class of natural volatile secondary metabolites extracted from plants, possessing the advantages of being green and pollution-free, and are currently mostly used in the development of repellents for inchworms. However, after being repelled, pests continue to cause damage in surrounding fields, and the effectiveness of repellents decreases significantly when the insect population density is high. Furthermore, directly spraying plant odor substances onto tea leaves not only results in rapid volatilization and a short-lasting effect, but may also affect the quality of the tea leaves.

[0018] Compared to repellents, this invention's product is based on plant-derived odor substances that act on the male tea geometrid moth's olfactory localization and mating process with the female. By reducing the effective egg-laying capacity of the female, it fundamentally reduces the geometrid moth population. Furthermore, this invention uses a slow-release bottle as the application carrier, ensuring that the active ingredient does not directly contact the tea leaves, thus guaranteeing application safety while effectively extending the duration of insecticidal effect. Two consecutive years of field trials have shown that a slow-release dose of 2.6 mL m⁻² of this interfering agent can reduce the tea geometrid moth population in tea gardens by more than 70%, providing sustained pest control. Attached Figure Description

[0019] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0020] Figure 1 γ-terpinene, camphor, verbenone, benzylnitrile, linalool, myrcene, phenol, borneol, 1,8-cineole, perillene, perilla aldehyde, lemonol, β-citronellol, geranial, geraniol, cinnamaldehyde, eugenol, anethole, cuminaldehyde, cumin The effects of 31 volatile components (alcohol, α-pinene, limonene, p-cymene, rosoxide, pentanal, heptanal, octanal, nonanal, decanal, dodecanal, and γ-undecalactone) on the effectiveness of inchworm pheromone traps. Figure 2 The effects of dodecanal, heptanal, octanal, nonanal, limonene, p-cymene, and pentanal on the effectiveness of sex decoys; Figure 3 The effect of a mixture of decanal, dodecanal, and limonene at different proportions on the effectiveness of an inchworm pheromone trap; Figure 4 Wherein, CK represents the control group area, Disturbing represents the interferon treatment area, and the effect of slow-release interferon treatment on the population of larvae of the tea geometrid moth is shown. Figure 5CK-1, CK-2, and CK-3 represent the control group area, and interference-1, interference-2, and interference-3 represent the interference agent treatment area. Aerial image showing the control effect of slow-release interference agent treatment on the population of larvae of the tea geometrid moth. Figure 6 High-density planting of *Tea geometrid moth* treated with plant-derived mating disruptor; Figure 7 Low-density planting of *Grey Tea Geometrid Moth* with plant-derived mating interference agent. Detailed Implementation

[0021] To better understand this invention, several experimental examples are provided below to illustrate its novel application in the field of tea tree plant protection. These experiments are intended to illustrate the invention and not to limit it. Example

[0022] Weigh out the components in the following dosage ratio: decanal: dodecanoal: limonene = 5:5:1; The mixture was injected into a 2 mL polypropylene (PP) slow-release bottle, and the bottle mouth was heat-sealed with an alcohol lamp. After standing at room temperature for 48 hours, the slow-release bottle of the mating interference agent was obtained. One slow-release bottle was placed in a transparent acrylic box (300*300*300 mm, with a mesh top). At 22:00, five unmated female and five unmated male and female *Geometrid moth* moths were introduced into the box and allowed to mate for 10 hours. At 8:00 the next morning, the female moths were removed from the box and placed in petri dishes to lay eggs. The hatching rate of the eggs laid by each female moth was investigated after 10 days. Example

[0023] Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 4:6:1.2, and perform other tests as in Example 1. Example

[0024] Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 6:4:0.8, and perform other tests as in Example 1. Example

[0025] Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 3:5:1, and perform other tests as in Example 1. Example

[0026] Weigh out the components in the following dosage ratio: decanal: dodecylal: limonene = 4:4:0.8, and perform other tests as in Example 1. Example

[0027] Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 6:5:1.2, and perform other tests as in Example 1.

[0028] Comparative Example 1 Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 0:5:1, and perform other tests as in Example 1.

[0029] Comparative Example 2 Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 5:5:0, and perform other tests as in Example 1.

[0030] Comparative Example 3 Weigh out the components in the following dosage ratio: decanal: dodecylaldehyde: limonene = 5:0:1, and perform other tests as in Example 1.

[0031] Comparative Example 4 (Control) At 22:00, without slow-release bottles, five unmated female and five unmated male and five unmated gray geometrid moths were directly introduced into the acrylic box. Other experimental methods were the same as in Example 1.

[0032] The hatching rates of oviposition by the female moths of the tea geometrid moth in each treatment are as follows: Table 1. Hatching rate of eggs laid by female moths of the tea geometrid moth under different ratios of the three components. Example 1 5 5 1 <![CDATA[0.31±0.08 a <!-- 4 -->]]> Example 2 4 6 1.2 <![CDATA[0.53±0.12 b ]]> Example 3 6 4 0.8 <![CDATA[0.39±0.1 a ]]> Example 4 3 5 1 <![CDATA[0.63±0.08 c ]]> Example 5 4 4 0.8 <![CDATA[0.49±0.05 b ]]> Example 6 6 5 1.2 <![CDATA[0.32±0.08 a ]]> Comparative Example 1 0 5 1 <![CDATA[0.79±0.06 d ]]> Comparative Example 2 5 5 0 <![CDATA[0.46±0.13 b ]]> Comparative Example 3 5 0 1 <![CDATA[0.47±0.16 b ]]> Comparative Example 4 (Control) 0 0 0 <![CDATA[0.87±0.03 e ]]> Examples 1, 3, and 6 showed the best results. Since dodecaldehyde has a higher boiling point than decanal and limonene, Example 1, with a higher proportion of dodecaldehyde, was selected as the proposed formulation to improve the overall sustained-release effect. Comparative experiments revealed that reducing any of the three components decreased the effectiveness of the sustained-release agent; therefore, the final formulation was determined to be decanal:dodecaldehyde:limonene = 5:5:1. Example

[0033] The field efficacy of a plant-derived mating disruptor for the tea geometrid moth was determined in Shaoxing City, Zhejiang Province. The experimental method involved preparing 2250 slow-release bottles of the mating disruptor with a ratio of decanal:dodecyl:limonene = 5:5:1, following the same method as in Example 1. Six plots, each 24 × 24 m in size, were established in a tea garden, spaced 20 m apart. Based on the criterion of no significant difference in average insect population between treatment plots, the six plots were divided into control (CK) and mating disruptor treatment plots, with three replicates for each treatment. In the mating disruptor treatment plots, one slow-release bottle of the disruptor was hung symmetrically at 1 m intervals on both sides of each tea row, for a total of 750 bottles per plot. Figure 6 No treatment was performed on plot CK. Twenty days later, the population size of *Tea geometrid moth* larvae on the tea plantation surfaces of each plot was surveyed, and images of each plot were taken using a drone (see the instruction manual appendix). Figure 5The survey method for inchworm larvae was as follows: At the beginning and end of the 4th, 6th, 8th, 10th, and 12th tea rows in each plot, a 6-meter section was removed. A point was then set up every 4 meters on the tea shed surface. The number of gray tea inchworm larvae within a 0.5 m² area centered on this point was surveyed. A total of 20 points were surveyed in each plot (see the appendix in the instruction manual). Figure 6 (The blue triangle in the middle).

[0034] Field trial results showed that the mating interference agent of the tea geometrid moth prepared in Example 1 of this invention, when used at a dosage of 2.6 mL m⁻², reduced the number of tea geometrid moths in the three treatment plots by 56.8%, 65.5%, and 73.1%, respectively, and the number of moths was significantly lower than that in the control group. Example

[0035] The field efficacy of a plant-derived mating disruptor for the tea geometrid moth was determined in Xianning City, Hubei Province. The experimental method involved preparing 726 slow-release bottles of the mating disruptor with a ratio of decanal:dodecyl:limonene = 5:5:1, following the same method as in Example 1. Six plots, each 20 × 16 m in size, were established in a tea garden, spaced 20 m apart. Based on the criterion of no significant difference in the average insect population between treatment plots, the six plots were divided into control (CK) and mating disruptor treatment plots, with three replicates for each treatment. In the mating disruptor treatment plots, one slow-release bottle of the disruptor was hung symmetrically at 2 m intervals on both sides of each tea row, for a total of 242 bottles per plot (see the instruction manual appendix). Figure 7 No processing is performed on cell CK. Other operations are the same as in Example 7.

[0036] Field trial results showed that the mating interference agent of the tea geometrid moth prepared in Example 1 of this invention, when used at a dosage of 1.51 mL m⁻², reduced the number of tea geometrid moths in the three treatment plots by 28.5%, 32.7%, and 39%, respectively, and the number of moths was significantly lower than that in the control group.

[0037] The above description is a further detailed explanation of the present invention in conjunction with specific embodiments. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, any simple modifications and substitutions made without departing from the concept of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. A plant-derived mating disruptor for the tea geometrid moth, characterized in that, The composition and weight ratio of the mating disruptor are: decanal: dodecylal: limonene = 4-6 parts: 4-6 parts: 0.8-1.2 parts.

2. The mating disruptor as described in claim 1, characterized in that, The mating disruptor has the following composition and weight ratio: decanal: dodecylal: limonene = 5:5:

1.

3. The mating disruptor as described in claim 1, characterized in that, The plant-derived mating disruptor for the tea geometrid moth can be used for the control of the tea geometrid moth in tea gardens.

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