Entomopathogen preparation for preventing and controlling sweet potato weevil as well as preparation method and application of entomopathogen preparation

Abstract

The invention discloses an entomopathogen preparation for preventing and controlling sweet potato weevil beetles as well as a preparation method and application of the entomopathogen preparation, and belongs to the technical field of agriculture. The entomopathogenic preparation for preventing and treating the sweet potato small weevils disclosed by the invention comprises an entomopathogenic nematode corpse compound agent and a sweet potato root protective agent, wherein the entomopathogenic nematode corpse compound agent comprises an entomopathogenic nematode corpse agent, an ipomoea batatas artificial feed, a polyphenol oxidase inhibitor and trehalose (alpha, alpha) dry powder in a mass ratio of (1-3): (6-8): (0.25-0.35): (0.6-0.8); every 1L of the sweet potato root protective agent contains 0.03-0.05 g of the biocontrol microbial agent, 3-5g of the sweet potato small weevil repelling agent, 90-110ml of the binder and the balance of water. The invention further discloses a preparation method of the entomopathogen preparation and application of the entomopathogen preparation in prevention and treatment of the sweet potato weevil. The entomopathogenic preparation disclosed by the invention plays a role in preventing and treating the sweet potato weevil jointly through multiple actions, and has a good preventing and treating effect on imagoes and larvae of the sweet potato weevil.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and in particular relates to an insect pathogen preparation for preventing and controlling sweet potato weevils, and a preparation method and application thereof. Background Art

[0002] The sweet potato weevil (Cylas formicarius) is a common sweet potato pest. Both its adults and larvae can cause damage to sweet potatoes, but the damage caused by the larvae is particularly serious. The larvae mainly bore into tubers and vines, forming irregular vertical and horizontal tunnels in which they excrete feces. The larvae of the sweet potato weevil live in tubers or vine heads throughout the entire stage. After the larvae hatch, they bore into the tubers and vine heads to form curved tunnels, and the back of the insect body is filled with white or brown insect feces. The larvae eat in the potato vines, generally boring downwards into relatively straight tunnels, causing the damaged area to gradually swell, and some can also bore into the tubers through the potato pedicels. There is usually only one larva in each tunnel, and there are only 1 to 2 larvae in each potato tuber, and as many as 100 or more.

[0003] The affected tubers will take on a honeycomb shape and turn black or dark brown. They are easily infected by sweet potato black spot and sweet potato soft rot, causing them to rot. The affected tubers will have a special fishy and spicy smell and are called "stinky potatoes". They are completely inedible. Even as feed, they can cause livestock to die of poisoning. The annual loss caused by the sweet potato weevil in the affected areas is about 15% to 20%, and in severe cases it can reach 50%, even leading to a complete crop failure.

[0004] At present, there are mainly the following methods for the prevention and control of sweet potato weevils: (1) Chemical control: Use chemical pesticides such as phoxim and trichlorfon for spraying or root irrigation. This method is effective quickly, but long-term use will lead to soil pollution, increase pest resistance, and pose certain risks to the environment and human health. (2) Physical control: Including covering the ground with film and setting up traps. The film can reduce the chance of adult insects laying eggs, and the trap can catch adult insects. These methods are relatively environmentally friendly, but the operation is complicated, the effect is limited, and it is difficult to promote and apply on a large scale. (3) Biological control: Use natural enemies such as parasitic wasps and predatory insects to control pests. In addition, biological pesticides such as Bacillus thuringiensis (Bt) can also be used. Biological control methods are environmentally friendly, but the effect is slow and is greatly affected by climate and ecological conditions. (4) Agricultural control: Reduce the overwintering sites of pests through measures such as crop rotation, deep plowing, and clearing field weeds. This method is simple and easy to implement, but it requires long-term persistence and has limited effect on pests that have already occurred. (5) Genetic engineering: breeding insect-resistant sweet potato varieties through genetic engineering technology. This method has great potential, but it is still in the research stage and has not yet been widely used. There are also ethical and safety controversies.

[0005] These control methods have their own advantages and disadvantages. Although chemical control is effective quickly, it has potential risks to the environment and human health. Physical control and biological control are more environmentally friendly, but the operation is complicated and the effect is limited. Agricultural control requires long-term persistence and has limited effect on existing pests. Genetic engineering methods have great potential, but are still in the research stage. Therefore, a combination of multiple methods combined with actual conditions can more effectively control the harm of sweet potato weevils. Summary of the invention

[0006] One of the purposes of the present invention is to provide an insect pathogen preparation for controlling sweet potato weevils, which can act from multiple aspects to control sweet potato weevil pests and has a good control effect on both adults and larvae of the sweet potato weevils.

[0007] The second object of the present invention is to provide a method for preparing the insect pathogen preparation.

[0008] The third object of the present invention is to provide the application of the insect pathogen preparation.

[0009] A fourth object of the present invention is to provide a method for using the insect pathogen preparation.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0011] In a first aspect, the present invention discloses an insect pathogenic preparation for controlling sweet potato weevils, comprising a compound of insect pathogenic nematode corpses and a sweet potato root protectant;

[0012] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, a polyphenol oxidase inhibitor and trehalose (α, α) dry powder, and the mass ratio thereof is 1-3: 6-8: 0.25-0.35: 0.6-0.8; preferably 2: 7: 0.3: 0.7;

[0013] Each 1L of sweet potato root protectant contains 0.03-0.05g of biocontrol agent, 3-5g of sweet potato weevil repellent, and 90-110ml of binder, and the volume is made up with water; preferably, it contains 0.04g of biocontrol agent, 4g of sweet potato weevil repellent, and 100ml of binder, and the volume is made up with water.

[0014] In some embodiments of the present invention, the preparation method of the insect pathogenic nematode corpse agent comprises the following steps: placing 4-5-year-old mature mealworm larvae in a container, and adding the infective insect pathogenic nematodes therein; the intact corpses of the mealworm larvae obtained after the mealworm larvae die are the insect pathogenic nematode corpse agent;

[0015] Preferably, 100 to 400 infective insect pathogenic nematodes are used for one mature mealworm larva.

[0016] In some embodiments of the present invention, the artificial feed for sweet potato weevils is made of the following components in parts by weight: 8-12 parts of sweet potato tuber roots, 5-8 parts of sweet potato flour, 1-2 parts of casein, 1-2 parts of cellulose, 3-5 parts of glucose, 3.00-5.26 parts of yeast powder, 7.50-9.78 parts of soybean flour, 4.49-5.64 parts of sucrose, 0.30-0.32 parts of ascorbic acid, 0.060-0.065 parts of cholesterol, 0.02-0.05 parts of methyl parahydroxybenzoate, 0.04-0.1 parts of potassium sorbate and 0.007-0.008 parts of complex vitamin B, 1.50-2.56 parts of agar and 70-75 parts of water;

[0017] Preferably, 10 parts of sweet potato tubers, 6.5 parts of sweet potato flour, 1.5 parts of casein, 1.5 parts of cellulose, 4 parts of glucose, 4.13 parts of yeast powder, 8.6 parts of soy flour, 5.06 parts of sucrose, 0.31 parts of ascorbic acid, 0.062 parts of cholesterol, 0.035 parts of methyl parahydroxybenzoate, 0.07 parts of potassium sorbate and 0.007 parts of vitamin B complex, 2.03 parts of agar and 72.5 parts of water.

[0018] In some embodiments of the present invention, the polyphenol oxidase inhibitor comprises gallic acid.

[0019] In some embodiments of the present invention, the sweet potato weevil repellent comprises at least one of Zanthoxylum bungeanum, catnip, and marigold;

[0020] The binder includes glutinous rice glue;

[0021] The biocontrol agent includes Beauveria bassiana.

[0022] In a second aspect, the present invention discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils, wherein the method prepares a compound preparation of insect pathogenic nematode corpses and a sweet potato root protectant, wherein the method for preparing the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0023] S1. Preparation of artificial feed for sweet potato weevils: The sweet potato tuber root was processed into a paste, and then mixed with the remaining components to obtain a paste mixture, which was sterilized to obtain artificial feed for sweet potato weevils;

[0024] S2. The polyphenol oxidase inhibitor is mixed evenly with the artificial feed of the sweet potato weevil to form a paste;

[0025] S3. Wrap the insect pathogenic nematode corpse agent with the paste prepared in step S2; and then wrap a layer of dry powder with trehalose (α, α) to obtain a compound agent of insect pathogenic nematode corpses;

[0026] The preparation method of the sweet potato root protective agent comprises the following steps: crushing the sweet potato weevil repellent into powder, uniformly mixing it with glutinous rice glue and Beauveria bassiana agent, adding water to form a hydrogel, and obtaining the sweet potato root protective agent.

[0027] In the present invention, the insect pathogenic nematode corpse agent is wrapped with mud paste and then coated with a layer of trehalose (α, α) dry powder on the outside, so that the insect pathogenic nematode corpse agent is sealed in the feed, and the vitality of the nematodes can be preserved while protecting the integrity of the corpse agent.

[0028] In a third aspect, the present invention discloses the use of the above-mentioned insect pathogenic agent in preventing and controlling sweet potato weevils.

[0029] In a fourth aspect, the present invention discloses a method for controlling sweet potato weevils using the above-mentioned insect pathogen preparation.

[0030] According to some embodiments of the present invention, when sowing sweet potatoes, a compound preparation of insect pathogenic nematode corpses is placed at the roots of the sweet potato seedlings, and a sweet potato root protectant is evenly dripped at the roots of the sweet potatoes.

[0031] In some embodiments of the present invention, the dosage of the sweet potato root protectant is 20-25 ml / seedling;

[0032] Preferably, the dripping area is a range of 10 to 15 cm in diameter centered on the base of the sweet potato seedling root.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention is scientifically designed and ingeniously conceived. The insect pathogenic preparation of the present invention jointly exerts the control effect of the sweet potato weevil through multiple effects. By wrapping the artificial feed of the sweet potato weevil on the surface of the insect pathogenic nematode worm preparation, some sweet potato weevil larvae can be attracted to come and feed, thereby reducing their damage to the sweet potato. At the same time, this also helps to guide the sweet potato weevil larvae to the vicinity of the insect pathogenic nematode, shortening the time for the insect pathogenic nematode to find a host. In addition, adding a polyphenol oxidase inhibitor such as gallic acid can effectively inhibit the humoral immune function of the sweet potato weevil, making the insect pathogenic nematode easier and faster to infect and kill the sweet potato weevil. The superposition of these three effects greatly enhances the control effect of nematodes on the sweet potato weevil, and effectively protects the sweet potato.

[0035] The sweet potato root protective agent of the present invention is evenly dripped at the root of the sweet potato when applied, and the dripping area is a circle centered on the base of the sweet potato seedling root, so as to form a protective layer around the root system; while repelling the sweet potato weevil from drilling into the soil and reducing the damage caused by drilling holes and laying eggs to the sweet potato tubers, it can also play a role when the adult insects contact the root system protective layer. Since the glutinous rice glue in the protective layer is sticky, it can adhere to and trap the approaching adult sweet potato weevil in the early stage, preventing them from invading the root system. In addition, when the sweet potato weevil passes through the protective layer, it will stick to lethal bacteria, which will infect the larvae that lay eggs and hatch and eventually die. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations. In the embodiments, if specific conditions are not specified, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0037] The glutinous rice glue described in the embodiment of the present invention is food grade glutinous rice glue.

[0038] The insect pathogenic nematode of the present invention is a commercial strain that is resistant to high temperatures. The insect pathogenic nematode used in the embodiments of the present invention is Steinernema carpocapsae insect pathogenic nematode.

[0039] The vitamin B complex described in the present invention is a vitamin B complex tablet produced by Huazhong Pharmaceutical Co., Ltd.

[0040] The Beauveria bassiana described in the present invention is produced by Shanxi Lvhai Pesticide Technology Co., Ltd., and its content is 40 billion per gram.

[0041] The 1% bifenthion·thiamethoxam granules (Yingzhuang) of the present invention are produced by Jiangmen Plant Protection Co., Ltd., and have a total effective ingredient content of 1%, a bifenthrin content of 0.5%, and a thiamethoxam content of 0.5%.

[0042] Example 1

[0043] This embodiment discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils of the present invention. The insect pathogenic preparation is composed of a compound of insect pathogenic nematode corpses and a sweet potato root protectant.

[0044] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, gallic acid and trehalose (α, α) dry powder, and the mass ratio thereof is 2:7:0.3:0.7;

[0045] Each 1L of sweet potato root protectant contains 0.04g of Beauveria bassiana, 4g of Zanthoxylum bungeanum (80-100 mesh), and 100ml of glutinous rice glue, and the volume is made up with water.

[0046] The preparation method of the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0047] (1) Preparation of insect pathogenic nematode corpse agent: Take 4-5-year-old mature mealworm larvae and place them in a container, and add infective insect pathogenic nematodes into the container; the intact corpses of the mealworm larvae obtained after death are the insect pathogenic nematode corpse agent; 300 infective insect pathogenic nematodes are used for one mature mealworm larvae.

[0048] (2) Preparation of artificial feed for sweet potato weevils: Prepare the following raw materials by weight: 10 parts of sweet potato tubers, 6.5 parts of sweet potato flour, 1.5 parts of casein, 1.5 parts of cellulose, 4 parts of glucose, 4.13 parts of yeast powder, 8.6 parts of soybean flour, 5.06 parts of sucrose, 0.31 parts of ascorbic acid, 0.062 parts of cholesterol, 0.035 parts of methyl parahydroxybenzoate, 0.07 parts of potassium sorbate, 0.007 parts of vitamin B complex, 2.03 parts of agar and 72.5 parts of water. Process the sweet potato tubers into a paste, and then mix it with the other ingredients to obtain a paste-like mixture, sterilize it, and obtain the artificial feed for sweet potato weevils.

[0049] (3) mixing gallic acid and the artificial feed of sweet potato weevils evenly to form a paste;

[0050] (4) Wrapping the insect pathogenic nematode corpse preparation with the mud paste prepared in step (3); and then wrapping it with a layer of trehalose (α, α) dry powder to obtain the insect pathogenic nematode corpse preparation.

[0051] The preparation method of the sweet potato root protective agent comprises the following steps: taking pepper powder crushed into 80-100 meshes, mixing it evenly with glutinous rice glue and Beauveria bassiana agent, adding water to 1L to form a hydrogel, and obtaining the sweet potato root protective agent.

[0052] When the compound preparation of insect pathogenic nematode corpses of the present embodiment is applied, 1-2 g (including 1-2 insect corpses) is applied to each hole, and 20-25 ml / each seedling is dripped with the sweet potato root protectant.

[0053] Example 2

[0054] This embodiment discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils of the present invention. The insect pathogenic preparation is composed of a compound of insect pathogenic nematode corpses and a sweet potato root protectant.

[0055] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, gallic acid and trehalose (α, α) dry powder, and the mass ratio thereof is 3:6:0.25:0.75;

[0056] Each 1L of sweet potato root protectant contains 0.03g of Beauveria bassiana, 3g of catnip (80-100 mesh), and 90ml of glutinous rice glue. The volume is made up to 1L with water.

[0057] The preparation method of the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0058] (1) Preparation of insect pathogenic nematode corpse agent: Take 4-5-year-old mature mealworm larvae and place them in a container, and add infective insect pathogenic nematodes into the container; the intact corpses of the mealworm larvae obtained after death are the insect pathogenic nematode corpse agent; 200 infective insect pathogenic nematodes are used for one mature mealworm larvae.

[0059] (2) Preparation of artificial feed for sweet potato weevils: Prepare the following raw materials by weight: 8 parts of sweet potato tubers, 8 parts of sweet potato flour, 2 parts of casein, 1 part of cellulose, 4.5 parts of glucose, 5.26 parts of yeast powder, 7.5 parts of soybean flour, 4.49 parts of sucrose, 0.3 parts of ascorbic acid, 0.062 parts of cholesterol, 0.05 parts of methyl parahydroxybenzoate, 0.04 parts of potassium sorbate, 0.007 parts of complex vitamin B, 2.56 parts of agar, and 72 parts of water. Process the sweet potato tubers into a paste, and then mix it with the other ingredients to obtain a paste-like mixture, sterilize it, and obtain the artificial feed for sweet potato weevils.

[0060] (3) mixing gallic acid and the artificial feed of sweet potato weevils evenly to form a paste;

[0061] (4) Wrapping the insect pathogenic nematode corpse preparation with the mud paste prepared in step (3); and then wrapping it with a layer of trehalose (α, α) dry powder to obtain the insect pathogenic nematode corpse preparation.

[0062] The preparation method of the sweet potato root protective agent comprises the following steps: taking catnip powder crushed into 80-100 meshes, mixing it evenly with glutinous rice glue and Beauveria bassiana agent, adding water to 1L to form a hydrogel, and obtaining the sweet potato root protective agent.

[0063] When the compound preparation of insect pathogenic nematode corpses of the present embodiment is applied, 1-2 g (including 1-2 insect corpses) is applied to each hole, and 20-25 ml / each seedling is dripped with the sweet potato root protectant.

[0064] Example 3

[0065] This embodiment discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils of the present invention. The insect pathogenic preparation is composed of a compound of insect pathogenic nematode corpses and a sweet potato root protectant.

[0066] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, gallic acid and trehalose (α, α) dry powder, and the mass ratio thereof is 1:8:0.35:0.65;

[0067] Each 1L of sweet potato root protectant contains 0.05g of Beauveria bassiana, 3.5g of marigold (80-100 mesh), and 105ml of glutinous rice glue, and the volume is made up to 1L with water.

[0068] The preparation method of the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0069] (1) Preparation of insect pathogenic nematode corpse agent: Take 4-5-year-old mature mealworm larvae and place them in a container, and add infective insect pathogenic nematodes into the container; the intact corpses of the mealworm larvae obtained after death are the insect pathogenic nematode corpse agent; 400 infective insect pathogenic nematodes are used for one mature mealworm larvae.

[0070] (2) Preparation of artificial feed for sweet potato weevils: Prepare the following raw materials by weight: 12 parts of sweet potato tubers, 5 parts of sweet potato flour, 1 part of casein, 2 parts of cellulose, 3 parts of glucose, 3 parts of yeast powder, 8 parts of soybean powder, 5.64 parts of sucrose, 0.31 parts of ascorbic acid, 0.065 parts of cholesterol, 0.03 parts of methyl paraben, 0.1 parts of potassium sorbate, 0.008 parts of complex vitamin B, 1.5 parts of agar, and 75 parts of water. Process the sweet potato tubers into a paste, and then mix it with the other ingredients to obtain a paste-like mixture, sterilize it, and obtain the artificial feed for sweet potato weevils.

[0071] (3) mixing gallic acid and the artificial feed of sweet potato weevils evenly to form a paste;

[0072] (4) Wrapping the insect pathogenic nematode corpse preparation with the mud paste prepared in step (3); and then wrapping it with a layer of trehalose (α, α) dry powder to obtain the insect pathogenic nematode corpse preparation.

[0073] The preparation method of the sweet potato root protective agent comprises the following steps: taking marigold powder crushed into 80-100 meshes, mixing it evenly with glutinous rice glue and Beauveria bassiana agent, adding water to 1L to form a hydrogel, and obtaining the sweet potato root protective agent.

[0074] When the compound preparation of insect pathogenic nematode corpses of the present embodiment is applied, 1-2 g (including 1-2 insect corpses) is applied to each hole, and 20-25 ml / each seedling is dripped with the sweet potato root protectant.

[0075] Example 4

[0076] This embodiment discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils of the present invention. The insect pathogenic preparation is composed of a compound of insect pathogenic nematode corpses and a sweet potato root protectant.

[0077] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, gallic acid and trehalose (α, α) dry powder, and the mass ratio thereof is 2.6:6.5:0.3:0.6;

[0078] Each 1L of sweet potato root protectant contains 0.04g of Beauveria bassiana, 2.3g of Zanthoxylum bungeanum (80-100 mesh), 2.2g of catnip (80-100 mesh), and 110ml of glutinous rice glue. The volume is made up to 1L with water.

[0079] The preparation method of the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0080] (1) Preparation of insect pathogenic nematode corpse agent: 4-5-year-old mature mealworm larvae are placed in a container, and the infective insect pathogenic nematodes are added thereto; the intact corpses of the mealworm larvae obtained after the death of the mealworm larvae are the insect pathogenic nematode corpse agent; 100 infective insect pathogenic nematodes are used for one mature mealworm larva.

[0081] (2) Preparation of artificial feed for sweet potato weevils: Prepare the following raw materials by weight: 9 parts of sweet potato tubers, 7 parts of sweet potato flour, 2 parts of casein, 1 part of cellulose, 5 parts of glucose, 4 parts of yeast powder, 9.78 parts of soybean flour, 5.2 parts of sucrose, 0.32 parts of ascorbic acid, 0.06 parts of cholesterol, 0.04 parts of methyl parahydroxybenzoate, 0.08 parts of potassium sorbate, 0.008 parts of complex vitamin B, 2 parts of agar, and 70 parts of water. Process the sweet potato tubers into a paste, and then mix it with the other ingredients to obtain a paste-like mixture, sterilize it, and obtain the artificial feed for sweet potato weevils.

[0082] (3) mixing gallic acid and the artificial feed of sweet potato weevils evenly to form a paste;

[0083] (4) Wrapping the insect pathogenic nematode corpse preparation with the mud paste prepared in step (3); and then wrapping it with a layer of trehalose (α, α) dry powder to obtain the insect pathogenic nematode corpse preparation.

[0084] The preparation method of the sweet potato root protective agent comprises the following steps: taking pepper powder and catnip powder crushed into 80-100 meshes, mixing them evenly with glutinous rice glue and Beauveria bassiana agent, adding water to 1L to form a hydrogel, and obtaining the sweet potato root protective agent.

[0085] When the compound preparation of insect pathogenic nematode corpses of the present embodiment is applied, 1-2 g (including 1-2 insect corpses) is applied to each hole, and 20-25 ml / each seedling is dripped with the sweet potato root protectant.

[0086] Example 5

[0087] This embodiment discloses a method for preparing an insect pathogenic preparation for controlling sweet potato weevils of the present invention. The insect pathogenic preparation is composed of a compound of insect pathogenic nematode corpses and a sweet potato root protectant.

[0088] The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, gallic acid and trehalose (α, α) dry powder, and the mass ratio thereof is 2.1:6.8:0.3:0.8;

[0089] Each 1L of sweet potato root protectant contains 0.05g of Beauveria bassiana, 1.7g of Zanthoxylum bungeanum (80-100 mesh), 1.7g of catnip (80-100 mesh), 1.6g of marigold (80-100 mesh), and 95ml of glutinous rice glue. Add water to make up the volume to 1L.

[0090] The preparation method of the compound preparation of insect pathogenic nematode corpses comprises the following steps:

[0091] (1) Preparation of insect pathogenic nematode corpse agent: Take 4-5-year-old mature mealworm larvae and place them in a container, and add infective insect pathogenic nematodes into the container; the intact corpses of the mealworm larvae obtained after death are the insect pathogenic nematode corpse agent; 200 infective insect pathogenic nematodes are used for one mature mealworm larvae.

[0092] (2) Preparation of artificial feed for sweet potato weevils: Prepare the following raw materials by weight: 11 parts of sweet potato tubers, 6 parts of sweet potato flour, 2 parts of casein, 1.5 parts of cellulose, 4 parts of glucose, 4.5 parts of yeast powder, 8.5 parts of soybean flour, 5 parts of sucrose, 0.3 parts of ascorbic acid, 0.063 parts of cholesterol, 0.02 parts of methyl parahydroxybenzoate, 0.06 parts of potassium sorbate, 0.007 parts of complex vitamin B, 2.3 parts of agar, and 71 parts of water. Process the sweet potato tubers into a paste, and then mix it with the other ingredients to obtain a paste-like mixture, sterilize it, and obtain the artificial feed for sweet potato weevils.

[0093] (3) mixing gallic acid and the artificial feed of sweet potato weevils evenly to form a paste;

[0094] (4) Wrapping the insect pathogenic nematode corpse preparation with the mud paste prepared in step (3); and then wrapping it with a layer of trehalose (α, α) dry powder to obtain the insect pathogenic nematode corpse preparation.

[0095] The preparation method of the sweet potato root protective agent comprises the following steps: taking pepper powder, catnip powder and marigold powder crushed into 80-100 meshes, mixing them evenly with glutinous rice glue and Beauveria bassiana agent, adding water to 1L to form a hydrogel, and obtaining the sweet potato root protective agent.

[0096] When the compound preparation of insect pathogenic nematode corpses of the present embodiment is applied, 1-2 g (including 1-2 insect corpses) is applied to each hole, and 20-25 ml / each seedling is dripped with the sweet potato root protectant.

[0097] Comparative Example 1

[0098] Compared with Example 1, this comparative example 1 does not contain the artificial feed of sweet potato weevils. When preparing the insect pathogenic nematode corpse compound, the insect pathogenic nematode corpse agent, trehalose and gallic acid are mixed with a small amount of water. 50 ml of water is added to every 1000 g of the insect pathogenic nematode corpse agent.

[0099] Comparative Example 2

[0100] Compared with Example 1, Comparative Example 2 does not contain gallic acid, a polyphenol oxidase inhibitor. In its preparation method, the insect pathogenic nematode necrosis agent is directly wrapped with the artificial feed of sweet potato weevils. The other conditions are the same as those of Example 1.

[0101] Comparative Example 3

[0102] Compared with Example 1, this comparative example 3 does not contain the sweet potato weevil repellent. When preparing the sweet potato root protective agent, the sweet potato weevil repellent is not added, and the other conditions are the same as those in Example 1.

[0103] Comparative Example 4

[0104] Compared with Example 1, this comparative example 4 does not contain the biocontrol agent. When preparing the sweet potato root protectant, no Beauveria bassiana agent is added, and the other conditions are the same as those in Example 1.

[0105] Comparative Example 5

[0106] Compared with Example 1, this comparative example does not contain insect pathogenic nematode necrosis agent. During preparation, gallic acid and sweet potato weevil artificial feed are mixed evenly to form a paste; an appropriate amount of the paste is taken and a layer of trehalose (α, α) dry powder is coated on the surface. The other conditions are the same as those in Example 1.

[0107] Test Example 1

[0108] This test example discloses an experiment of using the drug of the present invention to control sweet potato weevils.

[0109] 1. Trial location

[0110] Sweet potato experimental site in Tuanjie Village, Huatan Town, Changning County, Yibin City. The experimental site is a hilly dryland, and the sweet potato weevils are seriously damaged. The experiment was repeated 3 times, arranged in random blocks, and 30m2 was planted in each plot. 2 , management is the same as the local level, and the damage caused by small weevils to sweet potato tubers (damage index) and yield loss (yield loss rate) are investigated plant by plant at harvest and recorded.

[0111] Survey standards and calculation methods for small weevil damage indicators:

[0112] During the survey, the sweet potato tubers with weevils infestation were marked as 1, and those without infestation were marked as 0;

[0113] The grading standard for damage caused by weevils (potato tubers) is: 0: no disease; 1: the diseased area accounts for 1% to 5% of the total potato tubers; 3: the diseased area accounts for 5% to 10% of the total potato tubers; 5: the diseased area accounts for 10% to 20% of the total potato tubers; 7: the diseased area accounts for 20% to 50% of the total potato tubers; 9: the diseased area accounts for more than 50% of the total potato tubers.

[0114] The calculation formula of the weevil damage index is as follows:

[0115] Damage index (%) = [(1×C1+3×C3+5×C5+7×C7+9×C9) / total number of tubers×9]×100%; 1, 3, 5, 7, 9 represent the level of damage (tubers) caused by weevils, and C1-C9 represent the number of tubers damaged by weevils at each level;

[0116] The formula for calculating the victimization rate is as follows:

[0117] Damage rate (%) = number of damaged tubers / total number of tubers surveyed × 100%

[0118] The formula for calculating the control effect is as follows:

[0119] Control effect (%) = (damage rate in control area - damage rate in treatment area) / damage rate in control area × 100%

[0120] 2. Experimental Design

[0121] The whole group of the present invention is divided into: using the medicine of Example 1 of the present invention.

[0122] Treatment group 1: the drug of Comparative Example 1 was used.

[0123] Treatment group 2: the drug of comparative example 2 was used.

[0124] Treatment group 3: the drug of comparative example 3 was used.

[0125] Treatment 4 group: the drug of Comparative Example 4 was used.

[0126] Treatment 5 group: the drug of Comparative Example 5 was used.

[0127] Blank control group: no drug was administered.

[0128] Conventional control group: 1% biphenyl·thiamethoxam granules (Yingzhuang) at 5kg / 667m 2 Spread evenly on the ridge surface near the sweet potato plants.

[0129] When sowing sweet potatoes, put the insect pathogenic nematode corpse compound into the roots of the sweet potato seedlings, using 2g of the insect pathogenic nematode corpse compound for each sweet potato seedling.

[0130] The sweet potato root protectant is placed in a washing bottle and 20 to 25 ml per seedling is evenly dripped on the roots of the sweet potato; the dripping area is a circle with a diameter of 10 to 15 cm centered on the base of the sweet potato seedling root.

[0131] The blank group was not treated.

[0132] The control method of the conventional control group is: use 1% biphenyl thiamethoxam granules (Yingzhuang) at 5kg / 667m 2 Spread evenly on the ridge surface near the sweet potato plants.

[0133] The results are shown in the following table:

[0134] Table 1 Results of the sweet potato weevil control test

[0135] Group Hazard Index % Hazard rate% Effectiveness% Treatment 1 group 26.10±1.16cd 20.48±2.75b 50.97±6.56c Treatment 2 groups 27.31±0.83c 18.58±0.17b 55.52±0.40c Treatment 3 groups 23.55±0.64de 15.38±2.01c 63.19±4.81b Treatment 4 groups 20.93±1.75e 12.40±0.72cd 70.30±1.71ab Treatment 5 groups 31.64±2.40b 20.71±2.54b 50.42±6.08c The present invention is grouped into 14.14±1.62f 9.71±1.02d 76.74±2.42a Blank control group 44.63±2.87a 34.43±0.60a / Conventional control group 23.15±2.00de 13.72±1.42c 67.14±3.39b

[0136] The test results show that the hazard index and hazard rate of the treatment without insect pathogenic nematode cadavers (treatment group 5) are lower than those of the blank control group, but significantly higher than those of other treatment groups, indicating that the insect pathogenic cadavers play the most important role in the entire invention preparation and can effectively reduce the damage of sweet potato weevils to sweet potato tubers by larvae. In addition, the hazard rate of sweet potato weevils without artificial feed for sweet potato weevils and gallic acid, a polyphenol oxidase inhibitor, is significantly higher than that of the treatment group with all components of the invention, indicating that artificial feed for sweet potato weevils and polyphenol oxidase inhibitors can significantly improve the control effect of insect pathogenic nematodes on sweet potato weevils, indicating that artificial feed for weevils and gallic acid are indispensable. The hazard index of the treatment group without biocontrol agents and repellents for sweet potato weevils is significantly higher than that of the treatment group with all components of the invention, indicating that biocontrol agents and repellents for sweet potato weevils can also improve the protection of the preparation to sweet potato tubers and are indispensable.

[0137] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An insect pathogen preparation for controlling sweet potato weevils, characterized in that: Including insect pathogenic nematode corpse compound and sweet potato root protectant; The insect pathogenic nematode corpse compound comprises an insect pathogenic nematode corpse agent, an artificial feed for sweet potato weevils, a polyphenol oxidase inhibitor and trehalose (α, α) dry powder, and the mass ratio thereof is 1-3: 6-8: 0.25-0.35: 0.6-0.8; preferably 2: 7: 0.3: 0.7; Each 1L of sweet potato root protectant contains 0.03-0.05g of biocontrol agent, 3-5g of sweet potato weevil repellent, and 90-110ml of binder, and the volume is made up with water; preferably, it contains 0.04g of biocontrol agent, 4g of sweet potato weevil repellent, and 100ml of binder, and the volume is made up with water.

2. The insect pathogen preparation for controlling sweet potato weevils according to claim 1, characterized in that: The preparation method of the insect pathogenic nematode necrosis agent comprises the following steps: placing 4-5-year-old mature mealworm larvae in a container, and adding the insect pathogenic nematodes in the infective stage therein; The intact bodies of mealworm larvae obtained after their death are insect pathogenic nematode cadaveric agents; Preferably, 100 to 400 infective insect pathogenic nematodes are used for one mature mealworm larva.

3. An insect pathogen preparation for controlling sweet potato weevils according to claim 1 or 2, characterized in that: The artificial feed for sweet potato weevils is prepared from the following components in parts by weight: 8-12 parts of sweet potato tuber roots, 5-8 parts of sweet potato flour, 1-2 parts of casein, 1-2 parts of cellulose, 3-5 parts of glucose, 3.00-5.26 parts of yeast powder, 7.50-9.78 parts of soybean flour, 4.49-5.64 parts of sucrose, 0.30-0.32 parts of ascorbic acid, 0.060-0.065 parts of cholesterol, 0.02-0.05 parts of methyl parahydroxybenzoate, 0.04-0.1 parts of potassium sorbate, 0.007-0.008 parts of complex vitamin B, 1.50-2.56 parts of agar, and 70-75 parts of water; Preferably, 10 parts of sweet potato tubers, 6.5 parts of sweet potato flour, 1.5 parts of casein, 1.5 parts of cellulose, 4 parts of glucose, 4.13 parts of yeast powder, 8.6 parts of soy flour, 5.06 parts of sucrose, 0.31 parts of ascorbic acid, 0.062 parts of cholesterol, 0.035 parts of methyl parahydroxybenzoate, 0.07 parts of potassium sorbate and 0.007 parts of vitamin B complex, 2.03 parts of agar and 72.5 parts of water.

4. An insect pathogen preparation for controlling sweet potato weevils according to claim 1 or 2, characterized in that: The polyphenol oxidase inhibitors include gallic acid.

5. The insect pathogen preparation for controlling sweet potato weevils according to claim 1, characterized in that: The sweet potato weevil repellent comprises at least one of Chinese prickly ash, catnip and marigold; The binder comprises glutinous rice glue; The biocontrol agent includes Beauveria bassiana agent.

6. The method for preparing an insect pathogen preparation for controlling sweet potato weevils according to any one of claims 1 to 5, characterized in that: The insect pathogenic nematode corpse compound and the sweet potato root protective agent are prepared respectively, wherein the preparation method of the insect pathogenic nematode corpse compound comprises the following steps: S1. Preparation of artificial feed for sweet potato weevils: The sweet potato tuber root was processed into a paste, and then mixed with the remaining components to obtain a paste mixture, which was sterilized to obtain artificial feed for sweet potato weevils; S2. The polyphenol oxidase inhibitor is mixed evenly with the artificial feed of the sweet potato weevil to form a paste; S3. Wrap the insect pathogenic nematode corpse agent with the paste prepared in step S2; and then wrap a layer of dry powder with trehalose (α, α) to obtain a compound agent of insect pathogenic nematode corpses; The preparation method of the sweet potato root protective agent comprises the following steps: crushing the sweet potato weevil repellent into powder, mixing it evenly with glutinous rice glue and Beauveria bassiana agent, adding water to form a hydrogel, and obtaining the sweet potato root protective agent.

7. Use of the insect pathogenic agent according to any one of claims 1 to 5 in controlling sweet potato weevils.

8. A method for preventing and controlling sweet potato weevils, characterized in that: The insect pathogen preparation according to any one of claims 1 to 5 is used.

9. The method according to claim 8, characterized in that When sowing sweet potatoes, put the compound of insect pathogenic nematode corpses into the roots of sweet potato seedlings, and evenly drip the sweet potato root protector into the roots of sweet potatoes.

10. The method according to claim 9, characterized in that The dosage of sweet potato root protectant is 20-25 ml per seedling; Preferably, the dripping area is a range of 10 to 15 cm in diameter centered on the base of the sweet potato seedling root.