Use of 2,6,10-trimethyltridecane as a component of a green trap for the false chinch bug

Abstract

The application discloses application of 2,6,10-trimethyltridecane as a component of a piezodorus guildinii trapping agent. The inventors find that 2,6,10-trimethyltridecane has strong attraction to piezodorus guildinii, a major soybean pest, and the compound can be used to trap and control the quantity of piezodorus guildinii in a field, so as to achieve the purpose of green prevention and control. When the compound is combined with pheromones, the trapping efficiency can be obviously improved, and the number of mis-trapped natural enemy insects can be reduced, so that the compound has great application prospect.

Description

Technical Field

[0001] This invention relates to the field of green agriculture and plant protection, specifically to the application of 2,6,10-trimethyltridecane as a component of a spot bee stink bug attractant. Background Technology

[0002] Riptortus pedestris (Fab.) is a major pest of soybeans, often causing the plant to fail to turn yellow in late autumn, resulting in pods without beans, a condition known as "green rot" (Wei et al. 2023). Adult Riptortus pedestris are strong fliers, have a wide diet, and can evade pesticide treatments, making them difficult to control. The development of pheromone traps ("pheromone attractants") and food-derived compound traps ("food attractants") is of great significance for the green control and dynamic monitoring of this pest (Xu, Turlings 2018). Currently, Riptortus pedestris pheromone attractants have been commercialized in Japan, South Korea, and China (Mizutani et al. 2008; Rahman et al. 2018; Xu et al. 2023). Previous research by the inventors found that 1-octen-3-ol is a major odor molecule in soybeans and has a good trapping effect in the field (Xu et al. 2023). The inventors have already submitted a patent application for this achievement (Xu Hao, Li Jinbu 2023). However, whether the efficiency of the food attractant can be further improved remains to be explored.

[0003] The pheromone of the spotted bug (Aegilops spp.) comprises three components: (E,Z)-2-hexenoic acid-3-hexenyl ester, (E,E)-2-hexenoic acid-2-hexenyl ester, and tetradecyl isobutyrate ester (in a ratio of 1:5:1). While pheromone attractants can be prepared by artificially synthesizing these components, their effectiveness is poor: in soybean fields, the number of spotted bugs actually increases instead of decreasing (Rahman et al. 2018). This may be because the attractants also strongly attract the spotted bug's natural enemies, leading to accidental capture and ecological imbalance (Kim, Lim 2010; Leal et al. 1995; Mainali, Lim 2012). Therefore, while attractants can be used to monitor spotted bug population dynamics, they are not effective in controlling their numbers. Furthermore, the pheromone components consist of three compounds, resulting in high manufacturing costs and difficulties in widespread application. Developing efficient, green, and economical attractants is of great significance. The inventors previously discovered that 1-octen-3-ol has a strong attraction to the spotted bug and can be used to develop novel traps (Xu Hao, Li Jinbu 2023). This invention aims to develop more efficient compound traps and their combinations, improving trapping efficiency while reducing the number of accidentally trapped natural enemy insects.

[0004] References:

[0005] Kim S,Lim UT(2010),Seasonal occurrence pattern and within-plant eggdistribution of bean bug,Riptortus pedestris(Fabricius)(Hemiptera:Alydidae),and its egg parasitoids in soybean fields.Applied Entomology and Zoology,45:457-464.

[0006] Leal WS,Higuchi H,Mizutani N,Nakamori H,Kadosawa T,Ono M(1995),Multifunctional communication in Riptortus clavatus(Heteroptera:Alydidae):conspecific nymphs and egg parasitoid Ooencyrtus nezarae use the same adultattractant pheromone as chemical cue.Journal of Chemical Ecology,21:973-985.

[0007] Mainali BP,Lim UT(2012),Annual pattern of occurrence of Riptortuspedestris(Hemiptera:Alydidae)and its egg parasitoids Ooencyrtus nezarae Ishiiand Gryon japonicum(Ashmead)in Andong,Korea.Crop Protection,36:37-42.

[0008] Mizutani N,Yasuda T,Yamaguchi T,Moriya S(2008),Pheromone contents andphysiological conditions of adult bean bugs,Riptortus pedestris(Heteroptera:Alydidae),attracted to conspecific males during non-diapause and diapauseperiods in fields.Applied Entomology and Zoology,43:331-339.

[0009] Rahman MM,Kim E,Kim D,Bhuyain MM,Lim UT(2018),Use of aggregationpheromone traps increases infestation of adult Riptortus pedestris(Hemiptera:Alydidae)in soybean fields.Pest Management Science,74:2578-2588.

[0010] Wei Z et al.(2023),Transcriptional profiling reveals a critical roleof GmFT2a in soybean staygreen syndrome caused by the pest Riptortuspedestris.New Phytologist,237:1876-1890.

[0011] Xu H et al.(2023),A Faboideae-specific floral scent betrays seeds toan important granivore pest.Journal of Agricultural and Food Chemistry,71:12668-12677.

[0012] Xu H, Turlings TCJ (2018), Plant volatiles as mate-finding cues for insects. Trends in Plant Science, 23:100-111. Xu Hao, Li Jinbu (2023), Application of 1-octen-3-ol as a component of the spot bee trap. State Intellectual Property Office Application No.: 2022115546249. Summary of the Invention

[0013] The purpose of this invention is to address the shortcomings of existing technologies by providing a trapping agent, 2,6,10-trimethyltetrazine, which exhibits superior trapping efficacy compared to pheromones and 1-octen-3-ol at the same concentration. Furthermore, it possesses a simple and stable structure, and its production cost is lower than that of pheromone attractants (a three-component mixture). In addition, the trap prepared from 2,6,10-trimethyltetrazine and 1-octen-3-ol results in fewer accidental traps of predatory insects compared to pheromone attractants, causing less ecological disturbance and thus making it safer.

[0014] The 2,6,10-trimethyltridecane described in this invention, CAS: 3891-99-4, has the following structural formula:

[0015]

[0016] Specifically, this invention provides the application of 2,6,10-trimethyltridecane in the preparation of spot bee stink bug traps.

[0017] The present invention also provides the application of 2,6,10-trimethyltridecane in field traps for the friar bug.

[0018] The present invention also provides a spot bee stink bug attractant, which is prepared into a lure core with 2,6,10-trimethyltridecane as the active ingredient, and the preparation method can be in accordance with conventional methods in the art.

[0019] This invention also provides a trapping composition for the spotted bug, comprising 2,6,10-trimethyltridecane and a attractant. The attractant comprises (E,Z)-2-hexeno-3-hexenyl hexenoate (CAS: 153367-21-6), (E,E)-2-hexeno-2-hexenyl hexenoate (CAS: 54845-28-2), and tetradecyl isobutyrate (CAS: 167871-30-9), in a weight ratio of 1:5:1. This combined trapping composition exhibits superior pest trapping effectiveness compared to using any single ingredient, and also results in fewer accidental trappings of natural enemies, thus possessing the characteristics of high efficiency and environmental friendliness.

[0020] In some embodiments, the weight ratio of 2,6,10-trimethyltridecane to the signaling agent is 1:0.5 to 1.5; more specifically, it is 1:1.

[0021] This invention also provides the application of the spotted bug trapping agent or the spotted bug trapping composition described in this invention in field trapping of spotted bugs. Specific application methods can follow conventional methods in the art, for example: adding the spotted bug trapping agent or the spotted bug trapping composition into a wind-blade type trap and placing it in the field for trapping.

[0022] The beneficial effects of this invention are:

[0023] (1) The inventors discovered that 2,6,10-trimethyltridecane has a strong attraction to the soybean pistil, a major pest. This compound can be used to trap and control the number of pistils in the field, reduce the accidental capture of natural enemy insects, and achieve the purpose of green control. Secondly, it can monitor the population of pistils and guide the implementation time of other control measures.

[0024] (2) The trapping agent 2,6,10-trimethyltridecane disclosed in this invention has a better trapping effect than an equal amount of pheromone and 1-octen-3-ol; and its structure is simple and stable, and its production cost is lower than that of pheromone trapping agents. Attached Figure Description

[0025] Figure 1 This is a graph showing the antennal potential analysis of insects.

[0026] Figure 2 It is the potentiometric response of the male insect's antennae to 2,6,10-trimethyltetrazine or dichloromethane (solvent).

[0027] Figure 3 These are photos of trap processing and field photos.

[0028] Figure 4 This is a summary of data on the trapping effectiveness of the traps in fields in Nanjing and Suzhou.

[0029] Figure 5 This is a dynamic graph showing the trapping effect of the trap in fields in Nanjing and Suzhou.

[0030] Figure 6 This is a summary of data on the accidental capture of natural enemy insects (divided into parasitic and predatory insects) by traps in fields in Nanjing and Suzhou.

[0031] Figure 7 This is a summary of data on the accidental capture of different types of natural enemy insects by traps in fields in Nanjing and Suzhou. Detailed Implementation

[0032] The following examples are provided to better understand the present invention, but do not limit the invention. Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the experimental materials used in the following examples are all commercially available conventional biochemical reagents.

[0033] Example 1: Insect Antennae Locative Response

[0034] Using an insect antennal position meter ( Figure 1 Syntech (Netherlands) – We analyzed the potentiometric response of the antennae of the male *Symplocos spp.* to 2,6,10-trimethyltetane: 1, 10, and 100 μg of 2,6,10-trimethyltetane (all dissolved in 10 μL dichloromethane) were dropped onto filter paper in a 1 mL blue plastic pipette tip. The 2,6,10-trimethyltetane was then aspirated onto the antennae of the *Symplocos spp.* using a transient carrier gas and a continuous gas flow. The antennae were connected to the antennal electrodes via conductive adhesive (Spectra 360, Fairfield, USA). A transient carrier gas flow (4 mL / s) was initiated through a transient gas valve to deliver the compound into the system, and the voltage changes across the electrodes were recorded. The results are as follows: Figure 2 As shown, 1 μg of 2,6,10-trimethyltridecane induced a greater potential response in the antennae than the solvent control dichloromethane (t-test, P<0.001). Furthermore, the potential response in the antennae increased with increasing sample amounts (1, 10, 100 μg) (the letters in the bar chart indicate statistically significant differences, P<0.05, one-way ANOVA), suggesting that this compound may be the active compound of the attractant bee stink bug.

[0035] Example 2 Field Trial

[0036] like Figure 3 As shown, we prepared the decoy using the compound: 2,6,10-trimethyltetane or the control compound 1-octen-3-ol (control 1) was dropped onto the filter paper in the sample vial (sample weight 40 mg, gas chromatograph vial 2 mL). Figure 3 The black arrow indicates the location, along with a diagram of the homemade lure. A glass capillary tube (1.1 mm inner diameter) is inserted into the cap to allow the sample to be slowly released (release rate is 1.0 ± 0.3 mg / day, similar to that of a pheromone lure). The sample is then loaded into a wind-blade type trap. Figure 3 Beijing Zhongjie Sifang Biotechnology Co., Ltd. (hereinafter referred to as Zhongjie Sifang) placed bee-like bugs at trapping sites in soybean fields in Nanjing, Jiangsu (coordinates: 32.033°N, 118.877°E, three replicates, n=3) or Suzhou, Anhui (coordinates: 33.636°N, 117.082°E, four replicates, n=4); in addition, control 2 was a pheromone lure (i.e., pheromone attractant, purchased from Zhongjie Sifang, the components of which are (E,Z)-2-hexenoic acid-3-hexenyl ester, (E,E)-2-hexenoic acid-2-hexenyl ester and tetradecyl isobutyrate ester, with a total weight of about 40mg, the ratio of which is 1:5:1, and the release rate is 1.2±0.1mg / day; Figure 3The black arrow indicates a red adhesive strip. Control 3 consists of a pheromone (Zhongjie Sifang) + 2,6,10-trimethyltetrazine combination lure core (40mg of each active ingredient). Figure 3 (Indicated by black arrows). The catch was checked every 3 days in Nanjing and every 2 days in Suzhou. After recording the catch, the traps were emptied. The surveys in both locations lasted 13 times each. In Nanjing, the surveys lasted a total of 3 days / survey × 13 times = 39 days. The lures (including both attractants and homemade lures, both with a shelf life of four weeks) were replaced on the 9th survey. In Suzhou, the surveys lasted a total of 2 days / survey × 13 times = 26 days. The lures remained within their shelf life and were not replaced.

[0037] Data on trapping of the horned bee bug, such as Figure 4 As shown, the trapping results in Nanjing and Suzhou were similar; among them, the attraction of the compound 2,6,10-trimethyltetane described in this invention to the spotted bug was stronger than that of compound 1-octen-3-ol (control 1) and pheromone attractant (control 2); however, the attraction of the pheromone + 2,6,10-trimethyltetane combination lure (control 3) was the best (P<0.001, paired t-test); the data show that 2,6,10-trimethyltetane itself has a strong attraction to the spotted bug, and its efficacy is stronger than that of the three pheromone components and 1-octen-3-ol, which has certain application prospects; the combination of this compound with pheromones can significantly improve the trapping efficiency and has great application potential.

[0038] Figure 5 The data shows dynamic data of point bugs captured at different time points, indicating that the number of point bugs captured varies depending on the sampling time (difference effect of different sampling times: Nanjing is F). 12,140 =18.01, P<0.001; Suzhou is F 12,195 =26.17, P<0.001; statistical method: ANOVA), but overall, the combination of pheromone and 2,6,10-trimethyltetane as an attractant had the strongest attraction to the point bee bug (solid line in the figure), followed by the 2,6,10-trimethyltetane lure. The pheromone lure (i.e., the attractant itself) and the 1-octen-3-ol lure had similar attraction effects (difference effect between different attractants: Nanjing is F). 3,140 =44.99, P<0.001; Suzhou is F 3,195 =45.49, P<0.001; statistical method: ANOVA).

[0039] Referring to the method in Example 2, the number of insects accidentally captured by the natural enemies of the spotted bug wasp was examined, and the results are as follows: Figure 6 and Figure 7 As shown:

[0040] Figure 6The data summary of the accidentally captured natural enemies of Riptortus pedestris in different years (2022 - 2023, where the trapping data of Riptortus pedestris in 2022 has been shown in the previous patent application, application number: 2022115546249, and only the data of accidentally captured natural enemies are shown here), different locations (Nanjing 32.033°N, 118.877°E, Suzhou 33.636°N, 117.082°E), and different attractants (2,6,10 - trimethyltridecane, 1 - octen - 3 - ol, pheromone, and pheromone + invention compound combination) is presented. It can be found from the figure that the number of accidentally captured natural enemies by the pheromone is greater than that by 2,6,10 - trimethyltridecane, 1 - octen - 3 - ol, or the combination of pheromone + invention compound; this indicates that there are potential ecological safety hazards with this attractant. However, the two newly invented compounds are relatively safe for natural enemies; when they are used in combination with the pheromone respectively, it will also reduce the number of accidentally captured pheromone and increase ecological safety (***: P < 0.001, **: 0.001 < P < 0.01, *: 0.01 < P < 0.05; Paired t - test; NS indicates no significant difference).

[0041] Figure 7 The types of accidentally captured natural enemies are shown, including parasitic natural enemies: Clairvilliops breviforceps and Gryon japonicum; predatory natural enemies are: Propylaea japonica, Chrysoperla sp, Paederus sp, etc. It can be seen from the figure that the number of accidentally captured natural enemies by the attractant is more than that by other attractants. When 2,6,10 - trimethyltridecane or 1 - octen - 3 - ol is combined with the pheromone, it can reduce the number of accidentally captured natural enemies by the attractant (excluding Gryon japonicum), thus increasing the safety of the trap (*: P < 0.05; Paired t - test; NS indicates no significant difference).

Claims

Application of 1,2,6,10-trimethyltridecane in the preparation of spot bee stink bug traps. 2.2,6,10-Trimethyltetane in field trapping of the friar bug.

3. The application according to claim 2, characterized in that, The application involves adding 2,6,10-trimethyltetrazine to a wind-blade type trap and placing it in the field to trap animals.

4. Application of spot bug traps prepared with 2,6,10-trimethyltetane as the active ingredient in field trapping spot bugs.

5. A composition for attracting spotted bee bugs, characterized in that, It includes 2,6,10-trimethyltridecane and a attractant; the weight ratio of 2,6,10-trimethyltridecane and the attractant is 1:0.5 to 1.5; the attractant is ( E , Z )-2-Hexenoic acid-3-hexenyl ester, ( E , E A mixture of 2-hexenyl 2-hexenoic acid and tetradecyl isobutyrate, in a weight ratio of 1:5:

1.

6. The composition according to claim 5, characterized in that, The weight ratio of 2,6,10-trimethyltridecane to the signal inducer is 1:

1.

7. The use of the spot bug trapping composition according to claim 5 or 6 in field trapping spot bugs.

8. The application according to claim 7, characterized in that, The application involves adding the spot bee trapping agent composition into a wind-blade type trap and placing it in the field to trap the bees.

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