A kind of insecticidal active substance and its preparation method and application

Abstract

The invention provides a method for preparing an insecticidal activity substance from secondary metabolism products of long shoot trichoderma strains. The method comprises the following steps of: step 1: performing liquid fermentation on the long shoot trichoderma strains capable of producing the insecticidal activity substance so as to obtain a culture solution containing insecticidal activity metabolism products; and step 2: performing a crude extraction operation on the obtained culture solution containing the insecticidal activity metabolism products so as to obtain a crude extract of the insecticidal activity substance. The invention further provides the application of the insecticidal activity substance prepared by the preparation method in the respects of preventing and treating bemisia tabaci and strawberry red spiders. The insecticidal activity substance and the preparation method and the application thereof disclosed by the invention have the advantages that preventing and treating trialeurodes uaporariorum and the strawberry red spiders through the strains are safe and reliable, phytotoxicity is not produced, human health is not endangered, and environment is not polluted.

Description

technical field

[0001] The invention relates to the field of biological control of plant pests, in particular to an insecticidal active substance, in particular to an insecticidal active substance prepared from a secondary metabolite of Trichoderma longibrachiae, and the insecticidal active substance The preparation method and its application in biological control of plant pests, especially in the control of whitefly and strawberry spider mite. Background technique

[0002] Whitefly [Bemisia tabaci (Gennadius)], commonly known as the small white moth, is a worldwide pest. Originally in tropical and subtropical regions, with the help of seedlings of flowers and other economic crops, it spreads rapidly around the world and becomes a disaster. In recent years, it has also become a new pest in my country, harming tomatoes, cucumbers, peppers and other vegetables. and cotton and many other crops. Bemisia tabaci directly sucks plant juice, which leads to weakening of plants. Nymp...

Examples

Embodiment 1

[0044] Embodiment 1——Containing the preparation of the culture fluid of insecticidal activity metabolite

[0045] (1) First, according to the routine culture method of the microbiology laboratory, pick a small amount of Trichoderma longibrachiae bacteria blocks stored in 20% glycerol tubes and inoculate them on the surface of the PDA plate, and cultivate them at 26°C for four days, as the bacterial classification for the shake flask fermentation culture ,stand-by;

[0046] (2) Prepare 20L of liquid culture medium and distribute it in 100 1000mL Erlenmeyer flasks, each bottle has a filling volume of 200ml, with natural pH, sterilized at 121°C for 20min, and cooled for later use.

[0047] Wherein, the liquid medium is 100g peptone, 600g sucrose, 40g beef extract, 5g magnesium sulfate, 10g potassium dihydrogen phosphate, add distilled water to 20L;

[0048] (3) Under aseptic conditions, scrape the Trichoderma spores on the surface of the PDA plate to be used, inoculate them in a...

Embodiment 2

[0049] Embodiment 2——Preparation of the Crude Extract of Insecticidal Active Substance

[0050] First, the fermentation product of the above-mentioned Trichoderma longibrachiae liquid culture medium is centrifugally filtered to obtain 16L filtrate and 3L mycelium; Alcohol aqueous solution, eluted at a flow rate of 1.6L / h to remove impurities, and then eluted with 2L of 50% alcohol aqueous solution at a flow rate of 1.6L / h to collect insecticidal active ingredients; the obtained mycelium was soaked in 3L of 70% alcohol for 24hrs, filtered, Soak the filter residue in 3L of 70% alcohol for 24hrs, combine the filtrates twice, concentrate the filtrate to remove the alcohol and extract it twice with an equal volume of n-butanol; finally, elute the n-butanol phase active liquid with the previous macroporous adsorption resin with 70% ethanol The liquids were combined and concentrated into 30 g of crude extract.

Embodiment 3

[0051] Embodiment 3 - the preparation of a kind of emulsifiable concentrate

[0052] Get the crude extract 8g that obtains in the embodiment 2, dissolve with 30ml ethanol, add 40ml sec-butyl acetate and 20ml xylene to aid dissolution, finally add 10ml emulsifier SP-4099, obtain 100ml content and be 8% emulsifiable concentrate.

technical field

[0001] The invention relates to the field of biological control of plant pests, in particular to an insecticidal active substance, in particular to an insecticidal active substance prepared from a secondary metabolite of Trichoderma longibrachiae, and the insecticidal active substance The preparation method and its application in biological control of plant pests, especially in the control of whitefly and strawberry spider mite. Background technique

[0002] Whitefly [Bemisia tabaci (Gennadius)], commonly known as the small white moth, is a worldwide pest. Originally in tropical and subtropical regions, with the help of seedlings of flowers and other economic crops, it spreads rapidly around the world and becomes a disaster. In recent years, it has also become a new pest in my country, harming tomatoes, cucumbers, peppers and other vegetables. and cotton and many other crops. Bemisia tabaci directly sucks plant juice, which leads to weakening of plants. Nymp...

Examples

Embodiment 1

[0044] Embodiment 1——Containing the preparation of the culture fluid of insecticidal activity metabolite

[0045] (1) First, according to the routine culture method of the microbiology laboratory, pick a small amount of Trichoderma longibrachiae bacteria blocks stored in 20% glycerol tubes and inoculate them on the surface of the PDA plate, and cultivate them at 26°C for four days, as the bacterial classification for the shake flask fermentation culture ,stand-by;

[0046] (2) Prepare 20L of liquid culture medium and distribute it in 100 1000mL Erlenmeyer flasks, each bottle has a filling volume of 200ml, with natural pH, sterilized at 121°C for 20min, and cooled for later use.

[0047] Wherein, the liquid medium is 100g peptone, 600g sucrose, 40g beef extract, 5g magnesium sulfate, 10g potassium dihydrogen phosphate, add distilled water to 20L;

[0048] (3) Under aseptic conditions, scrape the Trichoderma spores on the surface of the PDA plate to be used, inoculate them in a...

Embodiment 2

[0049] Embodiment 2——Preparation of the Crude Extract of Insecticidal Active Substance

[0050] First, the fermentation product of the above-mentioned Trichoderma longibrachiae liquid culture medium is centrifugally filtered to obtain 16L filtrate and 3L mycelium; Alcohol aqueous solution, eluted at a flow rate of 1.6L / h to remove impurities, and then eluted with 2L of 50% alcohol aqueous solution at a flow rate of 1.6L / h to collect insecticidal active ingredients; the obtained mycelium was soaked in 3L of 70% alcohol for 24hrs, filtered, Soak the filter residue in 3L of 70% alcohol for 24hrs, combine the filtrates twice, concentrate the filtrate to remove the alcohol and extract it twice with an equal volume of n-butanol; finally, elute the n-butanol phase active liquid with the previous macroporous adsorption resin with 70% ethanol The liquids were combined and concentrated into 30 g of crude extract.

Embodiment 3

[0051] Embodiment 3 - the preparation of a kind of emulsifiable concentrate

[0052] Get the crude extract 8g that obtains in the embodiment 2, dissolve with 30ml ethanol, add 40ml sec-butyl acetate and 20ml xylene to aid dissolution, finally add 10ml emulsifier SP-4099, obtain 100ml content and be 8% emulsifiable concentrate.

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