Application of n-tritetradecane in preparation of aphidius gifuensis parasitic attractant

Abstract

The invention relates to application of n-tritetradecane in preparation of an aphidius gifuensis parasitic attractant, and belongs to the technical field of biopesticides. According to the technical scheme, the parasitism efficiency of the aphidius gifuensis to target pests can be improved, the parasitism potential of the aphidius gifuensis to unsuitable hosts can be expanded, therefore, the accuracy and stability of biological control are remarkably improved, meanwhile, a new technical means is provided for expanding propagation and utilization of the aphidius gifuensis, and the method is worthy of popularization and application. The method has an important application value for promoting the popularization of biological control in the agricultural field. Compared with a traditional mode depending on chemical pesticides, the method has the advantages that the problems of environmental pollution and pest resistance can be reduced, sustainable protection of an agricultural ecological system is achieved, development of a green prevention and control technology is promoted, and a new theoretical basis and an application tool are provided for comprehensive treatment of pests.

Description

Technical Field

[0001] This invention relates to the application of tetradecane in the preparation of aphid parasitoid attractant, belonging to the field of biopesticide technology. Background Technology

[0002] Aphids (Aphidoidea), also known as plant lice or honeydew insects, are a type of herbivorous insect. Currently, approximately 4,400 species of aphids have been identified across 10 families, with the majority belonging to the Aphididae family. They are among the most destructive pests on Earth.

[0003] Peach aphid ( Myzus persicae The tobacco aphid, also known as the tobacco aphid, is a major pest in tobacco production. It directly affects the growth of tobacco plants and induces sooty mold, causing serious losses to tobacco production. The long-term use of chemical pesticides to control tobacco aphids has led to a decline in biodiversity in the tobacco field ecosystem, a serious imbalance in the ecological environment, and an increase in pesticide residues in tobacco leaves. In addition to tobacco, the peach aphid can host more than 300 kinds of plants, including cruciferous vegetables, peppers, potatoes, eggplants, melons, soybeans, and wheat. After parasitizing, it seriously affects the photosynthesis and nutrient accumulation of various host crops, resulting in chlorosis and curling of leaves, deformed and dropped fruits, causing significant yield losses and quality decline, and causing great economic harm to agricultural production.

[0004] Parasitic wasps are an important group of parasitic insects belonging to the order Hymenoptera, and are widely used in the biological control of agricultural pests. Current research indicates that parasitic wasps have developed host recognition and selection mechanisms over a long evolutionary process, and their oviposition preferences directly affect the fitness of offspring and the effectiveness of control. Existing technology suggests that parasitic wasps identify hosts primarily through two pathways: first, by visually recognizing characteristics such as the host's shape, color, and size; and second, by using antennae or ovipositors to sense informational compounds directly related to the host for host identification. The host's chemical information is the most crucial signaling substance influencing the parasitic wasp's oviposition decisions. For example, the Encarsia formosa can use n-nonacontane to distinguish different whitefly hosts, suggesting that alkane substances on the insect's body surface may play an important role in parasitic wasp host recognition.

[0005] Tobacco aphid parasitic wasp ( Aphidius gifuensis The tobacco aphid parasitoid wasp (Begonia spp.) is the dominant parasitic wasp of the peach aphid. This wasp can also parasitize other agricultural pests such as the wheat aphid and cotton aphid. Its larvae develop inside the aphid, causing the host to die after forming a white, mummified aphid. Currently, the tobacco aphid parasitoid wasp is widely used in the biological control of peach aphids, especially in tobacco production. However, in practical applications, the parasitism efficiency of the tobacco aphid parasitoid wasp is affected by various factors, such as environmental conditions and host density, resulting in inconsistent control effects. Furthermore, the parasitism efficiency of the tobacco aphid parasitoid wasp varies significantly among different aphid species, which limits its widespread application.

[0006] Tetratriacontane, also known as n-Tetratriacontane, is a straight-chain alkane with CAS No. 14167-59-0 and molecular formula C 34 H 70 It is almost insoluble in water but soluble in many organic solvents, commonly used as lubricants and preservatives, and there is no report on the application of tetratriacontane in host recognition and oviposition decision of Aphidius. SUMMARY

[0007] In view of the deficiencies of the prior art, the application provides the application of n-tetratriacontane in the preparation of an Aphidius parasitic attractant.

[0008] The technical solution of the application is as follows: The application of n-tetratriacontane in the preparation of an Aphidius parasitic attractant.

[0009] According to the application, the content of n-tetratriacontane is 0.0005-0.01 g / mL, and the solvent is n-hexane.

[0010] Further preferably, the content of n-tetratriacontane is 0.0005 g / mL, and the solvent is n-hexane.

[0011] An Aphidius parasitic attractant comprises an effective amount of n-tetratriacontane.

[0012] According to the application, the content of n-tetratriacontane is 0.0005-0.01 g / mL, and the solvent is n-hexane.

[0013] Further preferably, the content of n-tetratriacontane is 0.0005 g / mL, and the solvent is n-hexane.

[0014] An aphid pest control method uses the Aphidius parasitic attractant to attract and enrich Aphidius, thereby improving the parasitic efficiency of Aphidius on aphid pests.

[0015] According to the application, the aphid pests are Myzus persicae and Aphis gossypii.

[0016] Advantages: The technical solution provided by the application not only improves the parasitic efficiency of Aphidius on target pests, but also expands the parasitic potential of Aphidius on non-suitable hosts, thereby significantly enhancing the precision and stability of biological control, and providing a new technical means for Aphidius propagation and utilization, which has important application value for promoting the popularization of biological control in the agricultural field.

[0017] Compared with the traditional method of relying on chemical pesticides, the method can reduce environmental pollution and pest resistance problems, realize sustainable protection of the agricultural ecosystem, promote the development of green prevention and control technology, and provide new theoretical basis and application tools for pest integrated management. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Experimental diagram for the influence of different alkane compounds on the parasitic behavior of Aphidius gifuensis. DETAILED DESCRIPTION

[0019] The technical solutions of the present application will be further described below in conjunction with the drawings and examples in the specification, but the scope of protection of the present application is not limited thereto.

[0020] In the following examples, the insect and plant materials used are as follows: The Aphidius gifuensis, Myzus persicae, Sitobion avenae, Rhopalosiphum maidis and Aphis gossypii used in the experiment were all from a sensitive population that had been continuously bred in the laboratory for more than 5 years. Before the experiment, the insects were collected using an insect aspirator and bred in a breeding cage (40 cm long, 50 cm wide, and 45 cm high). The breeding conditions were as follows: temperature 25℃±2℃, humidity 60%±10%.

[0021] Pepper was selected as the host plant for the experiment, and the pepper variety was Chuyanchao Tianjiao.

[0022] Example 1 Influence of different alkane compounds on the parasitic behavior of Aphidius gifuensis The inventors extracted the surface substances of four different aphids (Myzus persicae, Sitobion avenae, Rhopalosiphum maidis and Aphis gossypii) and analyzed them using GC-MS, obtaining five straight-chain alkane compounds, namely n-octadecane, n-eicosane, n-hexacosane, n-octacosane and n-tetracosane. The influence of these five compounds on the parasitic behavior of Aphidius gifuensis was then verified.

[0023] Preparation of test compound solutions: The compound solutions were prepared according to the solubility of different alkanes, and were gradiently diluted in order of the highest concentration. N-hexane (purity 99.5%) was used as the solvent to prepare 0.1, 0.01 g / mL n-octadecane solution, 0.5, 0.05 g / mL n-eicosane solution, 0.2, 0.02 g / mL n-hexacosane solution, 0.1, 0.01 g / mL n-octacosane solution, and 0.01, 0.001 g / mL n-tetracosane solution. The control group was n-hexane (purity 99.5%).

[0024] Host aphid treatment method: (1) In the breeding population, healthy aphids were selected, and n-hexane was used to extract the capillary tube with a melting point. The solution was evenly added to the surface of the aphids, covering the entire surface, and stayed for 5 minutes to elute the surface material of the aphids.

[0025] (2) After elution with n-hexane, the treatment group used a capillary tube with a melting point to add the test compound solution to the surface of the aphids, and the control group added n-hexane. The amount of addition was evenly covered on the entire surface of the aphids, and after staying for 5 minutes, the next parasitic selection experiment was carried out.

[0026] Behavior observation method: (1) The aphids treated in the above different groups were placed in leaf discs, and the leaf discs were placed in 3.5 cm culture dishes, with 3 aphids in each leaf disc; 30 groups were repeated.

[0027] The leaf discs were made of agar and pepper leaves. The agar was mixed with 1g agar powder and 100mL pure water, then heated in a microwave oven until the agar mixture became clear. Then it was taken out and evenly divided into 20 parts, and poured into 3.5cm culture dishes. After cooling and solidification, the leaves were placed in the culture dishes. The purpose of making leaf discs was to keep the leaves fresh and simulate the environment of parasitic wasps in natural conditions.

[0028] (2) Collect the pupae of Aphidius gifuensis and place them in an artificial climate chamber with a temperature of (25±2)℃, humidity of 60%±10%, and light cycle of 16:8 (L:D) h. Observe daily and take the newly emerged female Aphidius gifuensis within 24 hours for mating with an equal number of males. After the female and male Aphidius gifuensis have mated, take one healthy female Aphidius gifuensis for behavior experiment in the leaf disc.

[0029] (3) Observe and record the host selection behavior of female wasps, including searching, touching, and oviposition. The behavior characteristics are described in Table 1. Specifically, when the antennae of Aphidius gifuensis extend and move around the host, it is determined to be in the host searching stage. When the antennae or ovipositor of Aphidius gifuensis come into contact with the host surface but do not show oviposition behavior, it is determined to be in the identification stage. When the antennae of Aphidius gifuensis touch the host and continuously tap the host surface 2-3 times, and then the ovipositor is inserted into the host to complete oviposition, it is determined to be in the oviposition stage. The above behavior criteria are used to determine the different stages of host selection process of Aphidius gifuensis, in order to conduct quantitative analysis of host selection rules and parasitic efficiency. The entire behavior observation process was carried out in a room at (25±2)℃. The specific experimental diagram is shown in Figure 1 .

[0030] (4) Each observation lasted 5 minutes, and the main behavior characteristics of Aphidius gifuensis were recorded. If a certain behavior characteristic occurred multiple times within 5 minutes, it was recorded as 1 time, and if it did not occur, it was recorded as 0 times. After the time ended, each group was treated repeatedly, a total of 30 times, to ensure stable and reliable data.

[0031] The results are shown in Table 2, and the results show that there are significant differences in the effects of alkane solutions with different chain lengths and concentrations on the behavior of Aphidius gifuensis. Among them, the searching rate of Aphidius gifuensis is lower after treatment with n-eicosane and n-tetracosane groups, indicating that Aphidius gifuensis does not need to search more to locate the potential host, and the touching and oviposition rate of Aphidius gifuensis is significantly higher than that of the control group and other alkane compound groups. Among them, the effect of adding 0.05 g / mL of n-eicosane is the best, and the oviposition rate reaches 25.79%, and the oviposition rate of adding 0.001 g / mL of n-tetracosane is 22.3%; n-octadecane, n-hexacosane and n-octacosane have no obvious promoting effect on the host selection behavior of Aphidius gifuensis, the searching rate of Aphidius gifuensis is high, only part of the concentration will induce the antennal touch behavior, and cannot improve the oviposition success rate.

[0032] Table 1. Description of behavior characteristics of Aphidius gifuensis

[0033] Table 2. Behavior of Aphidius gifuensis after treatment in each group

[0034] Example 2 Effect of different concentrations of compounds on oviposition success rate of Aphidius gifuensis Preparation of test compound solution: Use n-hexane (purity 99.5%) as a solvent to prepare 0.005, 0.001, 0.0008, 0.0005 g / mL n-eicosane solution and n-tetracosane solution.

[0035] The host aphid treatment method and behavior observation method are the same as in Example 1, wherein the original group is not treated and is directly placed in healthy peach aphids.

[0036] Table 3. Effect of different concentrations of compounds on oviposition rate of Aphidius gifuensis

[0037] The results are shown in Table 3, and the results show that there are significant differences in the effects of different concentrations of n-eicosane and n-tetracosane solutions on the oviposition success rate of Aphidius gifuensis. Low concentration (≤0.0008 g / mL) n-eicosane has no promoting effect on the parasitic behavior of Aphidius gifuensis; n-tetracosane in the low concentration range (0.0005-0.0008 g / mL) has very strong oviposition attraction activity to Aphidius gifuensis, and can achieve efficient oviposition at 0.0005 g / mL, which is 5.57% higher than the natural parasitism rate of the dominant host peach aphid.

[0038] Example 3 Effect of n-tetracosane on the parasitic behavior of Aphidius gifuensis on cotton aphids Preparation of the solution of the compound to be tested: A solution of n-tetracontane at 0.0015 g / mL was prepared using n-hexane (purity 99.5%) as solvent.

[0039] The host aphid treatment method and the behavior observation method were the same as in Example 1, wherein the original group was directly placed into healthy 2-3 instar cotton aphids without any treatment.

[0040] Table 4. Behavior of C. nicashildes after treatment in each group

[0041] The results are shown in Table 4, which show that the n-tetracontane treatment group of C. nicashildes has an oviposition rate of 26.67% on cotton aphids, which is 10% higher than the parasitism rate of the original group, proving that n-tetracontane can significantly promote the parasitism rate of C. nicashildes on non-dominant host cotton aphids.

Claims

1. Use of n-tetratriacontane in the preparation of a parasitism attractant of Aphidius gifuensis.

2. Use according to claim 1, wherein The content of the n-tetratriacontane is 0.0005-0.01 g / mL, and the solvent is n-hexane.

3. Use according to claim 2, wherein the compound is ###0002### The content of the n-tetratriacontane is 0.0005 g / mL, and the solvent is n-hexane.

4. A parasitic wasp Cotesia floridanum attractant, characterized in that, It comprises an effective content of n-tetratriacontane.

5. The Aphidius nicolaevii parasitoid attractant as set forth in claim 4, wherein, The content of the n-tetratriacontane is 0.0005-0.01 g / mL, and the solvent is n-hexane.

6. The Aphidius nicolaevii parasitoid attractant as set forth in claim 5, wherein, The content of the n-tetratriacontane is 0.0005 g / mL, and the solvent is n-hexane.

7. A method for controlling aphid pests, characterized by, The parasitism attractant of Aphidius gifuensis of claim 4 is used for Aphidius gifuensis attractant enrichment, so as to improve the parasitism efficiency of Aphidius gifuensis on aphid pests.

8. The method of claim 7, wherein, The aphid pests are Myzus persicae and Aphis gossypii.

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