RU2080065C1 - Bacterial insecticide for struggle against lepidoptera - Google Patents

Abstract

FIELD: microbiological industry, biotechnology. SUBSTANCE: invention proposes new bioinsecticide based on highly productive strain of Bacillus thuringiensis spp. kurstaki for struggle against Lepidoptera. EFFECT: enhanced effectiveness of bioinsecticide. 2 cl, 6 tbl

Description

 The invention relates to the field of microbiological industry and biotechnology and is the creation of a new biological insecticide for the control of lepidopteran (leaf-eating) insects based on a strain of Bacillus thuringiensis spp. kurstaki H3a3b.

 Losses of agricultural crops from harmful insects reach 30%. Damage by harmful insects to forestry is high. The most dangerous insect pests of agriculture include leaf-eating insects that destroy a number of crops, including agricultural crops, rice, cotton, vegetables, etc.

To control harmful insects, chemical insecticides are used that are quite effective, but have a number of serious drawbacks:
1) non-specificity of action (damage to beneficial insects);
2) high environmental pollution;
3) cumulative effect in soil, air, water;
4) the emergence of insect resistance to insecticides.

 In recent years, biological insecticides based on the spore-crystalline complex of Bacillus thuringiensis have been widely used. The toxic effect of this complex is due to the action of crystalline protein toxins.

 The technical result of the claimed invention consists in creating, based on a strain of Bacillus thuringiensis spp. kurstaki H3a3b is a new bio-insecticidal drug with physicochemical parameters that improve its performance. The preparation of a new bioinsecticide is a wettable powder, characterized by optimal morphometric composition, stability of working suspensions, and rapid wettability.

The closest in technical solution to bioinsecticides is the drug "Lepidocide" based on the producer strain Bacillus thuringiensis spp. kurstaki Z-52 [1] as follows: crystalline endotoxin 9 12% spores 8 10% culture medium residues 63 72% table salt 2 7% kaolin 3 13% [2]
The proposed drug is a new highly effective bioinsecticide for controlling leaf-eating insects: pests of fruit crops of the apple moth, apple and fruit moth, American white butterfly, silkworm, leafworm; pests of garden crops (on cabbage, beets, carrots) - cabbage and turnip whites, cabbage scoops, moths, moths; pests of medicinal crops moths, goldfin.

 The drug is not toxic to humans and other warm-blooded animals, bees, does not pollute the environment, can be used near recreation areas, ponds, child care facilities. It can also be used in large farms, on farms and horticultural plots.

Example 1. The method of preparation of the drug. 1.1 Cultivation of the producer strain and concentration of the target product. For the cultivation of producer Bacillus thuringiensis spp. kurstaki H3a3b uses an enzyme, standard mediums in tap water (yeast polysaccharide medium of yeast - 30.0 g / l; corn flour 15.0 g / l; pH 6.8 7.2), seed (1.0%). Temperature 28 30 ^o C. The process ends when 50 70% of the cells completes the stage of spore formation, while there is a yield of crystals (controlled by light-optical methods). Fermentation time 24 32 hours. Spore titer in the culture fluid 3.5 4.0 billion spores / ml. After cultivation, the culture fluid is separated and then biomass containing spores and crystals is isolated, concentrating on spray drying.

 1.2 Obtaining the finished formulation. To obtain an insecticide formulation, a spore-crystalline concentrate of Bac. thuringiensis spp. kurstaki with the remains of the nutrient medium is mixed with the following components: sulfonol; ammonium sulfate; pentacalitriphosphate (or tripolyphosphate); a piece of chalk. Depending on the titer of spores in the concentrate, the ratio of additive concentrate may fluctuate, however, the spore in the preparation should be at least 70 billion spores per gram (Table 1).

 The selection of the components of the drug was carried out in order to improve the physico-chemical characteristics of the drug: increase hygroscopicity; decreased ability to clump, hang, caking and sticking; increase abrasive properties.

 The advantages of the main physico-chemical parameters of the new insecticide are presented in table. 2. For comparison, similar parameters of the drug "Lepidocide" are given.

 Example 2. Laboratory tests of bioinsecticides on unpaired silkworms. Laboratory studies of the insecticide on the tracks of unpaired silkworms were carried out. The experiment took 15 caterpillars of unpaired silkworms of younger ages (three replicates for each breeding). The test bioinsecticide in appropriate dilutions (1.0 ml) was added to the semi-synthetic feed (3.0 g per cup), which was placed on top of the Petri dish. The food was made on the basis of beans with the addition of preservatives and vitamins. The effectiveness of the drug was evaluated on the 6th day, determining the average flying concentration that caused the death of 50% of insect individuals (LC-50) according to the Steinhaus formula with the corrections of Abbot [3]. The data obtained are presented in table. 3.

 Given in the table. 3 results allow to conclude that the drug is effective against unpaired silkworms and is well stored at room temperature for a long time.

 Example 3. Laboratory tests of an insecticide in the control of cabbage pests in Belarus. In 1991 and 1992 In the Belarusian Research Institute of Plant Protection, laboratory tests of the insecticide formulation on cabbage of the Belorusskaya cultivar at the Dawn farm were conducted. The standard was the drug "Lepidocide". Caterpillars of cabbage white served as a test object. Natural food (cabbage leaves) was treated with a solution of an insecticide of different concentrations. Leaves for control were treated with water.

 The activity of the samples was determined by the average lethal concentrations. Data on the toxic effects of the drug are presented in table. 4.

 Example 4. Field trials of an insecticide for the control of cabbage pests in Belarus.

 In 1991, 1992, field tests of bioinsecticide were carried out in Belarus at the farm "Dawn", when the cabbage plants were in the phase of beginning of tying of a kachan. The cabbage was treated with a Gardena knapsack sprayer with a working fluid consumption of 500 l / ha. The results of the experiments are presented in table. 5.

 Example 5. Tests of the biological effectiveness of an insecticide against leafworms on an apple tree.

 In 1991, in Ukraine, the Kamensky state farm conducted field trials of an insecticide on apple trees against leafworms. The results were evaluated after the 3rd, 6th and 9th day, which was associated with checking the safety of the insecticide on the leaves of the apple tree. The data are given in table. 6.

 Thus, the results of laboratory and field tests of the new bioinsecticide carried out over several years in various climatic and geographical areas of the CIS and on various representatives of leaf-eating insects indicate a high efficiency of the insecticide (0.8 1.0 kg / ha lead to a decrease in the number of harmful insects by 85 95%). The preparative form has an improved preparative form, it is soluble in water, does not dust, is not phytoxic at the recommended consumption rates.

Literature
1. Zurabova E.R. Rassomakhina N.A. Handakova D.D. Yudina T.G. Timonkina Yu. N. Davydyuk V.N. Kruglyakova G.P. Dergalyuk I.K. Strain Bac. thturingiensis var. kurstaki Z-52, producer of o-endotoxin. Auth. St. N 769787, 1984.

 2. Lepidocide concentrated. TU 64-15-03-87. M. 1987.

 3. Ashmarin I.P. Vorobyov A.A. Static methods in microbiological research. M. Medgiz, 1962.

Claims (1)

 Lepidoptera bacterial insecticide containing a spore-crystalline complex of bacteria Bacillus thuringiensis spp. kurstaki with the remains of the nutrient medium and the target additive, characterized in that the target additive contains sulfazole, ammonium sulfate and tripolyphosphate in the following ratio, wt. Spore-crystalline complex of bacteria Bacillus thuringiensis spp kurstaki with the remains of the nutrient medium 35 65
Targeted additive containing sulfonol (40 parts by weight), ammonium sulfate (40 parts by weight), tripolyphosphate (16 parts by weight) 65 35
2. The insecticide according to claim 1, characterized in that the target additive additionally contains up to 4 parts by weight enriched chalk inclusive.

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