Pentadecane parasitic wasp attractant and its application

Abstract

The present invention discloses a pentadecane parasitic wasp attractant and its application. Compared with existing pest attractants on the market, the pentadecane attractant provided by the present invention attracts beneficial parasitic wasps, eliminating growers' concerns about attracting more pests to their fields. Furthermore, the more beneficial insects there are, the better the field pest control effect. In addition to the pale-footed braconid wasp, the parasitic wasp attractant of the present invention may not only attract parasitic wasps of the Noctuidae family, but also other types of parasitic wasps, thereby increasing the number of parasitic wasps in the field and improving the parasitic wasp parasitism rate in the field, achieving the effect of parasitic wasps controlling field pests.

Description

Technical Field

[0001] The present invention relates to the technical field of biological pesticides, such as natural enemy attractants, and in particular to a pentadecane parasitic wasp attractant and applications thereof. Background Art

[0002] Parasitic wasps are important parasitic natural enemy insects that play an important role in the green control of crop pests. Female parasitic wasps and their offspring usually regulate the physiological state of the host through parasitic behavior, ensuring that the parasitic wasp offspring develop normally on the surface or inside the host, allowing their population to reproduce, and the host pests to be effectively controlled. At present, many parasitic wasps have been successfully commercialized and used in the biological control of rice and vegetable pests, such as the trichogrammatid wasp used to control the rice stem borer, the aphid wasp used to control vegetable aphids, etc. Microplitis pallidipes, as a dominant parasitic wasp of the middle and young larvae of vegetable armyworms, likes to parasitize the 2nd-3rd instar armyworm larvae with clustering habits, and is an important regulator of the natural population size of armyworm pests in the field.

[0003] However, for parasitic wasps, the ability to accurately locate and identify their hosts and successfully parasitize them directly determines the survival and reproduction of their offspring populations. Previous studies have found that parasitic wasps primarily search for hosts by olfactory recognition of chemical signaling substances related to the host, and that these signaling substances can be derived from a variety of sources, such as pest-inducing plant volatiles, the host itself, and its feces. Therefore, by exploring the volatile odorants associated with the directional behavior of the pallid-footed braconid wasp and utilizing them to effectively regulate the efficiency of the parasitic wasp's host search, thereby achieving the goal of controlling target pests, this will provide a new green means and technology for the green prevention and control of pests. Compared with other pest control technologies, this new natural enemy olfactory behavior regulation technology has the advantages of being green, environmentally friendly, pollution-free, safe, efficient, and highly selective, and will have broad application prospects in integrated pest management. Summary of the Invention

[0004] The purpose of the present invention is to provide a pentadecane parasitic wasp attractant, a preparation method and an application thereof. The attractant can attract parasitic wasps, improve the parasitic wasps' ability to search and locate target pests, and thus improve their parasitic efficiency, thereby achieving effective biological control of pests, reducing the application of chemical pesticides, and ensuring the safety of vegetable products.

[0005] The object of the present invention is achieved through the following specific technical solutions:

[0006] Application of pentadecane in the preparation of parasitic wasp attractants.

[0007] Optionally, the content of pentadecane is 1.0% to 98%.

[0008] Optionally, the content of pentadecane is 5.0%.

[0009] Optionally, the content of pentadecane is 10.0%.

[0010] Optionally, the parasitic wasp is the pallidostachys parasiticus.

[0011] Optionally, the pentadecane is n-pentadecane.

[0012] A pentadecane parasitic wasp attractant, characterized in that the pentadecane parasitic wasp attractant comprises the following components in percentage by mass:

[0013] n-Pentadecane 1.0%~98.0%;

[0014] Conventional excipients 2.0%~99.0%.

[0015] Optionally, the content of n-pentadecane is 5.0%.

[0016] Optionally, the content of n-pentadecane is 10.0%.

[0017] A method for controlling Noctuidae pests comprises using any one of the pentadecane parasitic wasp attractants of the present invention to attract and enrich parasitic wasps, thereby parasitizing 2nd-3rd instar Noctuidae larvae and regulating the number of Noctuidae pests.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] Compared to existing pest attractants on the market, the pentadecane attractant provided by the present invention attracts beneficial parasitic wasps, eliminating growers' concerns about attracting more pests to their fields. Furthermore, the more beneficial insects there are, the better the field pest control effect. In addition to the palustris, the parasitic wasp attractant provided by the present invention may not only attract parasitic wasps of the Noctuidae family, but also other parasitic wasps, thereby increasing the number of parasitic wasps in the field and improving their parasitism rate, effectively controlling field pests with parasitic wasps.

[0020] Pentadecane used in the present invention as the attractant volatile substance is a natural plant product with the characteristics of low toxicity and easy degradation, and is a friendly and safe attractant for humans, animals and the ecological environment.

[0021] In the present invention, pentadecane can be obtained by various methods, such as chemical synthesis, direct extraction from plants, etc., and can be produced on an industrial scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0023] Figure 1 This is a structural diagram of a "Y"-shaped olfactometer, where the direction indicated by the arrow is the direction of gas flow in the tube. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0025] Pentadecane (Pentadecane, molecular formula: C 15 H 32 Pentadecane (molecular weight: 212.41; CAS number: 629-62-9; its structural formula is shown below) is a colorless liquid at room temperature and pressure, and evaporates into a colorless gas with a faint, distinctive odor. It is commonly used in organic synthesis and gas chromatography analysis. Its high latent heat and low melting point make it an ideal candidate for a phase change material (PCM) for cooling applications. A search of existing technical literature reveals no reports on the use of pentadecane as an attractant for parasitic wasps, the natural enemies of pests.

[0026]

[0027] Pentadecane is used to prepare a parasitic wasp attractant. For example, the pentadecane content can be 1.0% to 98%. Alternatively, the pentadecane content can be 5.0%. Alternatively, the pentadecane content can be 10.0%.

[0028] The parasitic wasp is Parasitoides pallidatids; the pentadecane is n-pentadecane.

[0029] The present invention provides a pentadecane parasitic wasp attractant, which comprises the following components in percentage by weight: 1.0% to 98.0% of n-pentadecane; 2.0% to 99.0% of conventional auxiliary materials. Alternatively, the content of n-pentadecane is 5.0%. Alternatively, the content of n-pentadecane is 10.0%.

[0030] In the pentadecane parasitic wasp attractant of the present invention, pentadecane is used as the active substance, the pentadecane is n-pentadecane, and the parasitic wasp is Pseudocera pallidula.

[0031] Conventional excipients can be one or more of solubilizers, synergists, emulsifiers, etc.; solubilizers are one or more of sodium dodecylbenzenesulfonate, potassium dodecylbenzenesulfonate, polysorbate, polyethylene glycol, sorbitol polyoxyethylene ether, lignin sulfonate, tea dregs, saponins, etc.; emulsifiers are spans, tweens, ethylene glycol esters, propylene glycol esters and / or polyethylene glycol-type nonionic surfactants, etc.; synergists are tea saponin, polyoxyethylene ether, etc.

[0032] The preparation method of the pentadecane parasitic wasp attractant of the present invention comprises:

[0033] (1) Pentadecane is used as the active ingredient to prepare a pentadecane parasitic wasp attractant; the pentadecane is prepared by diluting it with paraffin oil, lanolin or ethanol.

[0034] (2) Pentadecane is weighed according to the above ratio and dissolved in a solvent. Various additives are optionally added and various forms of attractants are prepared according to various processes, such as powders, emulsifiable concentrates, suspensions, dry suspensions, concentrated emulsions, sustained-release preparations, nanoformulations, aqueous emulsions, sprays, etc. The solvent can be one or more organic solvents such as paraffin oil, lanolin, water, ethanol, methanol, acetone, cyclohexanone, petroleum ether, petroleum aromatics, pure benzene, ethyl acetate, toluene, xylene, etc.

[0035] A method for controlling Noctuidae pests comprises utilizing the pentadecane parasitic wasp attractant of the present invention to attract and enrich parasitic wasps, thereby parasitizing 2nd-3rd instar Noctuidae larvae and regulating the number of Noctuidae pests.

[0036] In the present invention, a "Y"-type olfactometer method is used to conduct a directional behavioral response test on the pallidipes wasp in a laboratory.

[0037] The specific method is as follows: Figure 1 As shown, each arm of a Y-shaped tube (2 cm inner diameter, 5 cm straight tube length, two equal 7.5 cm arms, and a 60° angle between the arms) is connected to an air flow meter, an odor source glassware, and an activated carbon tube. The air flow meter controls the gas flow rate, directing the gas emitted from the odor source along the side arm tube toward the Y-shaped tube's tee. The Y-shaped olfactometer is placed in an 80 cm × 80 cm × 50 cm box. A fluorescent lamp is placed above the Y-shaped olfactometer. The room temperature is maintained at (26 ± 1)°C, and the gas flow rate in the tube is 300 mL / min.

[0038] The specific experimental procedure was as follows: Due to the biological characteristics of the pale-footed parasitic wasp, the experiment was conducted daily from 8:30 AM to 5:00 PM. First, the various instruments were connected. Then, a mated female wasp was removed from a test tube and placed into a Y-shaped tube using a bee aspirator. The wasp's behavioral response was observed. If the parasitic wasp reached one-third of the way to one of the two arms within 5 minutes and remained there for more than 5 seconds, it was considered a choice. Otherwise, if the parasitic wasp showed no response or remained there for less than 5 seconds within 5 minutes, the wasp was considered to have made no choice, and the analysis of that individual was terminated. To minimize error, 60 wasps were tested per sample, and each female was tested only once. The arms of the Y-shaped tube were swapped after every five wasps were tested. After testing 10 wasps, a new Y-shaped tube was reconnected and testing continued. At the end of each day's experiment, all instruments were cleaned with 95% alcohol, dried, and stored.

[0039] Parasitoid selection rate = number of volatile compounds selected by parasitoids / total number of parasitoids in the experiment * 100;

[0040] Example 1: Attraction of different compounds to Pseudocephalides pallidati

[0041] 1g of a volatile compound was weighed, 1ml of Tween 80 emulsifier was added, and finally, the mixture was dropped into paraffin oil and diluted to 100ml. The mixture was mixed thoroughly to prepare an attractant. The volatile compound content was adjusted to 0.1g / ml (10%). The selectivity was then determined using a "Y"-type olfactometer selection method. The selectivity of parasitic wasps for each volatile compound is shown in Table 1. The volatile compounds used in this experiment were standard products purchased from a reagent company. Volatile compounds include: α-Farnesene, α-phellandrene, Ocimene, Geraniol, cis-Jasmone, 2-Ethyl hexanol, cis-3-Hexenyl hexanoate, cis-3-Hexenyl isovalerate, Heptadecane, 1-Penten-3-ol, Caproaldehyde, Benzyl alcohol, and Pentadecane.

[0042] Table 1 Selectivity of P. pallidipes for different volatile compounds

[0043]

[0044] As shown in Table 1, P. pallidipes exhibited varying degrees of selectivity for the 13 different volatile compounds tested in this study. The parasitic wasp exhibited relatively high selectivity for cis-jasmone and pentadecane, at 64.81% and 64.29%, respectively. Statistical analysis revealed that only cis-jasmone and pentadecane exhibited significant differences in selectivity compared to the blank control (P < 0.05).

[0045] Example 2: Attraction of different concentrations of pentadecane to Pseudocycota pallidipes

[0046] This embodiment differs from embodiment 1 in that the volatile compound is pentadecane. Pentadecane was measured and dropped into paraffin oil to dissolve, and attractants with mass concentrations of 0.005 (0.5%), 0.01 (1.0%), 0.05 (5.0%), 0.1 (10%), 0.5 (50%), and 0.98 g / mL (98%) were prepared. The selection effect of parasitic wasps on each volatile compound is shown in Table 2:

[0047] Table 2 Effects of different concentrations of pentadecane on the selectivity of Pseudospondylus pallidipes

[0048]

[0049]

[0050] The results in Table 2 show that pentadecane is attractive to P. pallidipes at concentrations ranging from 1.0% to 10%, and the selectivity of P. pallidipes for pentadecane is relatively high at concentrations between 1.0% and 5.0%. Furthermore, 98% pentadecane also exhibited strong attracting power for P. pallidipes. However, it is worth noting that at a pentadecane concentration of 0.5%, the attraction rate for P. pallidipes was 28%, indicating that at this concentration, P. pallidipes exhibited an avoidance response. Therefore, in practical applications, the appropriate dosage should be selected based on a comprehensive consideration of both attractant efficacy and cost; a higher concentration of a compound does not necessarily guarantee a stronger attractant effect.

[0051] The experimental results of Example 1 and Example 2 show that among the 13 different types of volatile compounds tested by the present invention, the parasitic wasps have a higher selectivity for cis-jasmone and pentadecane, and the statistical analysis results also show significant differences. The attraction rate reaches more than 64% when the mass concentration is 10%; in addition, through the selectivity experiment of different concentrations of pentadecane, it is proved that at a mass concentration of 1.0% to 10%, the parasitic wasp selection rate maintains a high level of more than 64%, and can be used as a parasitic wasp attractant.

[0052] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above. Other embodiments can be obtained by varying the component contents in the above embodiments. Those skilled in the art may make various variations or modifications within the scope of the claims without affecting the essence of the present invention.

[0053] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

Claims

1. Use of pentadecane for preparing a parasitic wasp attractant, wherein the parasitic wasp is Pseudocycota pallidipes; and the pentadecane is n-pentadecane; The mass concentration of pentadecane is 0.01-0.1 g / mL.

2. The use according to claim 1, characterized in that The mass concentration of pentadecane is 0.05 g / mL.

3. A method for controlling Noctuidae pests, characterized in that: The method uses n-pentadecane with a mass concentration of 0.01-0.1 g / mL to attract and enrich the parasitic wasp, thereby parasitizing the 2nd-3rd instar larvae of Noctuidae and regulating the number of Noctuidae pests.

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