Application of 2, 6, 10-trimethyltridecane as ingredient of green trapping agent for point bugs

Abstract

The invention discloses an application of 2, 6, 10-trimethyltridecane as an ingredient of a trapping agent for Emblycoris cerus. The inventor finds that the 2, 6, 10-trimethyltridecane has strong attraction to the major soybean pest, namely, the bee bugs, and the 2, 6, 10-trimethyltridecane can be used for trapping and controlling the number of the bee bugs in the field, so that the purpose of green prevention and control is achieved; when the insect trapping agent is combined with pheromone for use, the trapping efficiency can be obviously improved, the number of caught natural enemy insects by mistake is reduced, and great application prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the fields of green agriculture and plant protection, and specifically to the application of 2,6,10-trimethyltridecane as a component of a Riptortus pedestris trap. Background Art

[0002] Riptortus pedestris (Fab.) is a major pest on soybeans, often causing symptoms such as "not turning yellow in late autumn and having pods but no beans" in soybean plants, that is, "symptom green" (Wei et al. 2023); Riptortus pedestris adults have strong flight ability and a wide range of feeding habits, and will avoid pesticide treatment, resulting in great difficulty in controlling them. The development of pheromone traps (abbreviated as "pheromone traps") and food-source compound traps (abbreviated as "food traps") is of great significance for the green prevention and control and dynamic monitoring of this pest (Xu, Turlings 2018); currently, pheromone traps for Riptortus pedestris 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 the main odor molecule of soybeans and has good trapping effects in the field (Xu et al. 2023). The inventors have submitted a patent application for this achievement (Xu Hao, Li Jinbu 2023). However, whether the efficiency of food traps can be further improved remains to be explored.

[0003] The pheromone of Riptortus pedestris includes three components: (E,Z)-3-hexenyl (E,Z)-2-hexenoate, (E,E)-2-hexenyl (E,E)-2-hexenoate, and tetradecyl isobutyrate (in a ratio of 1:5:1); by artificially synthesizing pheromone components, pheromone traps can be prepared, but the trapping effect is poor: when using pheromone traps in soybean fields, the number of Riptortus pedestris does not decrease but increases instead (Rahman et al. 2018). This may be because pheromone traps also have strong attraction to natural enemy insects of Riptortus pedestris, thus mis-trapping natural enemies and leading to ecological imbalance (Kim, Lim 2010; Leal et al. 1995; Mainali, Lim 2012). Therefore, pheromone traps can be used to monitor the population dynamics of Riptortus pedestris, but cannot effectively control its number. In addition, the pheromone components include three compounds, with high manufacturing costs and great difficulty in popularization. Developing efficient, green and economical traps is of great significance. The inventors previously found that 1-octen-3-ol has strong attraction to Riptortus pedestris and can be used to develop new traps (Xu Hao, Li Jinbu 2023). The present invention aims to develop more efficient compound traps and their combined products, while improving the trapping efficiency and reducing the number of mis-traps of natural enemy insects.

[0004] References:

[0005] Kim S, Lim UT(2010), Seasonal occurrence pattern and within-plant egg distribution 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 adult attractant pheromone as chemical cue. Journal of Chemical Ecology, 21:973-985.

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

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

[0009] Rahman MM, Kim E, Kim D, Bhuyain MM, Lim UT(2018), Use of aggregation pheromone 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 role of GmFT2a in soybean staygreen syndrome caused by the pest Riptortus pedestris. New Phytologist, 237:1876-1890.

[0011] Xu H et al.(2023), A Faboideae-specific floral scent betrays seeds to an 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 trapping agent for Riptortus pedestris. Application number of the State Intellectual Property Office: 2022115546249 Patent. Summary of the Invention

[0013] The object of the present invention is to provide a trapping agent, 2,6,10 - trimethyltridecane, in view of the deficiencies in the prior art. Its trapping effect is better than that of pheromone and 1 - octen - 3 - ol with the same content. Moreover, it has a simple and stable structure, and the production cost is lower than that of the signal trapping agent (a three - component mixture). In addition, the trapping agent prepared from 2,6,10 - trimethyltridecane and 1 - octen - 3 - ol has fewer mis - captures of natural enemy insects than the signal trapping agent, resulting in less ecological interference, so it is safer.

[0014] The 2,6,10 - trimethyltridecane described in the present invention has CAS: 3891 - 99 - 4, and its structural formula is as follows:

[0015]

[0016] Specifically, the present invention provides the application of 2,6,10 - trimethyltridecane in the preparation of a trapping agent for Riptortus pedestris.

[0017] The present invention also provides the application of 2,6,10 - trimethyltridecane in trapping Riptortus pedestris in the field.

[0018] The present invention also provides a trapping agent for Riptortus pedestris, which is prepared into a lure core with 2,6,10 - trimethyltridecane as the active ingredient, and the preparation method can follow the conventional methods in the art.

[0019] The present invention also provides a trapping composition for Riptortus pedestris, and the composition includes 2,6,10 - trimethyltridecane and the signal trapping agent. The components of the signal trapping agent described in the present invention include (E,Z) - hex - 2 - enyl hex - 3 - enoate (CAS: 153367 - 21 - 6), (E,E) - hex - 2 - enyl hex - 2 - enoate (CAS: 54845 - 28 - 2) and tetradecyl isobutyrate (CAS: 167871 - 30 - 9), and the weight ratio of the three is 1:5:1. The pest trapping effect of this combined trapping agent is better than that of using them alone, and the mis - capture amount of natural enemies is also less than that of the signal trapping agent. Therefore, it has the characteristics of high efficiency and greenness.

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

[0021] The present invention also provides the application of the Riptortus pedestris trapper or the Riptortus pedestris trapping composition of the present invention in trapping Riptortus pedestris in the field. The specific application method can be carried out according to the conventional methods in the art. For example, the Riptortus pedestris trapper or the Riptortus pedestris trapping composition is added into a windmill-shaped trapper and placed in the field for trapping.

[0022] Advantages of the present invention:

[0023] (1) The inventor found that 2,6,10-trimethyltridecane has a strong attraction to the major soybean pest Riptortus pedestris. By using this compound, the number of Riptortus pedestris can be trapped and controlled in the field, reducing the accidental trapping of natural enemy insects and achieving the purpose of green prevention and control. Secondly, it can monitor the population number of Riptortus pedestris and guide the implementation time of other control measures.

[0024] (2) The trapper 2,6,10-trimethyltridecane disclosed in the present 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 the production cost is lower than that of the pheromone trapper. Description of the drawings

[0025] Figure 1 It is an electroantennogram analysis diagram of insects.

[0026] Figure 2 It is the electroantennogram response of the male antenna to 2,6,10-trimethyltridecane or dichloromethane (solvent).

[0027] Figure 3 It is a photo of the trapper treatment category and a field photo.

[0028] Figure 4 It is the data summary of the trapping power of the trapper in the fields of Nanjing and Suzhou.

[0029] Figure 5 It is a dynamic diagram of the trapping power of the trapper in the fields of Nanjing and Suzhou.

[0030] Figure 6 It is the data summary of the accidental trapping of natural enemy insects (divided into parasitic and predatory) by the trapper in the fields of Nanjing and Suzhou.

[0031] Figure 7 It is the data summary of the accidental trapping of different species of natural enemy insects by the trapper in the fields of Nanjing and Suzhou. Detailed implementation manners

[0032] The following examples are convenient for better understanding of the present invention, but do not limit the present invention. The experimental methods in the following examples are all conventional methods unless otherwise specified. The test materials used in the following examples are all conventional biochemical reagents purchased from stores unless otherwise specified.

[0033] Example 1 Insect Antennae Electroantennogram Response

[0034] Using an insect electroantennogram apparatus ( Figure 1 , Syntech, Netherlands), we analyzed the electroantennogram response of the antennae of male Riptortus pedestris to 2,6,10-trimethyltridecane: We dropped 1, 10, and 100 μg of 2,6,10-trimethyltridecane (all dissolved in 10 μL of dichloromethane) onto filter paper in blue plastic pipette tips (1 mL) respectively, and blew 2,6,10-trimethyltridecane onto the antennae of Riptortus pedestris through transient carrier gas and continuous air flow. The antennae were connected to both ends of the antennal electrode through conductive glue (Spectra 360, Fairfield, USA); by opening the transient air valve to start the transient carrier gas (4 mL / second), the compound was sent into the system, and the voltage change at both ends of the electrode was recorded. The results are as Figure 2 shown. The electroantennogram response of the antennae induced by 1 μg of 2,6,10-trimethyltridecane was greater than that of the solvent control dichloromethane (t-test, P < 0.001), and with the increase in the amount of sample used (1, 10, 100 μg), the electroantennogram response of the antennae also increased accordingly (the letters on the bar graph indicate significant differences in statistical analysis, P < 0.05, one-way ANOVA), indicating that this compound may be an active compound attracting Riptortus pedestris.

[0035] Example 2 Field Experiment

[0036] As Figure 3 shown, we made lures with the compound: We dropped 2,6,10-trimethyltridecane or the control compound 1-octen-3-ol (Control 1) onto filter paper in sample bottles (sample weight 40 mg, gas chromatography vial 2 mL, Figure 3 marked with a black arrow, and a schematic diagram of the self-made lure), and inserted a glass capillary (inner diameter 1.1 mm) into its lid to allow the sample to slowly release (release rate 1.0 ± 0.3 mg / day, and its release rate is similar to that of the pheromone lure). The samples were placed in a windmill-type trap ( Figure 3 , Beijing ZhongJieSiFang Biotech Co., Ltd., hereinafter referred to as ZhongJieSiFang) and placed 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) to trap Riptortus pedestris; in addition, Control 2 was a pheromone lure (i.e., sex attractant, purchased from ZhongJieSiFang, with the components being (E,Z)-2-hexenoic acid-3-hexenyl ester, (E,E)-2-hexenoic acid-2-hexenyl ester and tetradecyl isobutyrate, total weight about 40 mg, and their ratio being 1:5:1, release rate 1.2 ± 0.1 mg / day; Figure 3The black arrow indicates a red rubber strip), Control 3 is a pheromone (ZhongJieSiFang) + a combined lure of 2,6,10-trimethyltridecane (each with 40 mg of active ingredient, Figure 3 marked with a black arrow). The capture amount was checked every 3 days in Nanjing and every 2 days in Suzhou. After recording the trapping amount, the trap was emptied. The investigations in both places lasted for 13 times. That is, in Nanjing, it lasted for a total of 3 days / time × 13 times = 39 days, and its lures (including the pheromone attractant and the self-made lure, with a validity period of four weeks each) were replaced at the 9th time. In Suzhou, it lasted for a total of 2 days / time × 13 times = 26 days, and the lures were all within the validity period and not replaced.

[0037] The trapping data of Riptortus pedestris is as Figure 4 shown. The trapping results in Nanjing and Suzhou are similar; among them, the compound 2,6,10-trimethyltridecane described in the present invention has a stronger attraction to Riptortus pedestris than the compound 1-octen-3-ol (Control 1) and the pheromone attractant (Control 2); however, the combined lure of pheromone + 2,6,10-trimethyltridecane (Control 3) has the best attraction (P < 0.001, Paired t-test); the data shows that 2,6,10-trimethyltridecane itself has a strong attraction to Riptortus pedestris, and its efficacy is stronger than that of the three-component pheromone and 1-octen-3-ol, and it has certain application prospects; when this compound is used in combination with the pheromone, the trapping efficiency can be significantly improved, and it has great application prospects.

[0038] Figure 5 The dynamic data of capturing Riptortus pedestris at different time points is shown, indicating that at different sampling times, the number of Riptortus pedestris trapped is different (the difference effect at different sampling times: in Nanjing, F 12,140 = 18.01, P < 0.001; in Suzhou, F 12,195 = 26.17, P < 0.001; the statistical method is ANOVA), but generally speaking, the attractant of the combination of pheromone and 2,6,10-trimethyltridecane has the strongest attraction to Riptortus pedestris (the solid line in the figure), followed by the 2,6,10-trimethyltridecane lure, while the pheromone lure (i.e., the pheromone attractant) and the 1-octen-3-ol lure have similar attracting effects (the difference effect of different attractants: in Nanjing, F 3,140 = 44.99, P < 0.001; in Suzhou, F 3,195 = 45.49, P < 0.001; the statistical method is ANOVA).

[0039] Referring to the method of Example 2, the number of accidentally trapped natural enemy insects of Riptortus pedestris was investigated, and the results are as Figure 6 and Figure 7 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 + invented 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 + invented 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 can also reduce the number of accidentally captured natural enemies by the 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 of multiple species 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 of multiple species by the attractant (but not including Gryon japonicum), thereby increasing the safety of the trap (*: P < 0.05; Paired t - test; NS indicates no significant difference).

Claims

1. Application of 2,6,10-trimethyltridecane in preparing the trapping agent for Riptortus pedestris Fabricius.

2. Application of 2,6,10-trimethyltridecane in trapping Riptortus pedestris Fabricius in the field.

3. The application according to claim 2, wherein The said application is that 2,6,10-trimethyltridecane is added into a windmill-shaped trap and placed in the field for trapping.

4. A trap for bee-margin stink bugs, characterized in that:

3. A lure core is prepared with 2,6,10-trimethyltridecane as the active ingredient.

5. Application of the trapping agent for Riptortus pedestris Fabricius as claimed in claim 4 in trapping Riptortus pedestris Fabricius in the field.

6. A Riptortus pedestris trapping agent composition, characterized in that, It includes 2,6,10-trimethyltridecane and a signal attractant.

7. The composition according to claim 6, characterized in that, The said signal attractant is a mixture of (E,Z)-3-hexenyl (E)-2-hexenoate, (E,E)-2-hexenyl (E)-2-hexenoate and tetradecyl isobutyrate, and the weight ratio of the three is 1:5:

1.

8. The composition according to claim 6, characterized in that, The weight ratio of 2,6,10-trimethyltridecane to the signal attractant is 1:0.5 - 1.5, preferably 1:

1.

9. Application of the trapping agent composition for Riptortus pedestris Fabricius as claimed in any one of claims 6 - 8 in trapping Riptortus pedestris Fabricius in the field.

10. The application according to claim 9, wherein The said application is that the trapping agent composition for Riptortus pedestris Fabricius is added into a windmill-shaped trap and placed in the field for trapping.

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