Helicoverpa armigera nuclear polyhedrosis virus WV104, composite suspending agent and application

Abstract

The invention belongs to the technical field of pest control, and particularly provides a cotton bollworm nuclear polyhedrosis virus WV104 which is preserved in the China Center for Type Culture Collection (CCTCC) in June 2024, and the preservation number is CCTCC NO: V202461. The virus has the advantages of wide insecticidal spectrum, high toxicity and the like, and has good insecticidal activity on larvae of various lepidoptera pests. The insecticidal composition has a good control effect on oriental tobacco budworms, can remarkably reduce the harm degree of the oriental tobacco budworms and improve the yield and quality of crops, is harmless to the environment and human health, meets the requirements of green agriculture development, and has important significance on development of efficient insect virus insecticides and biological control of pests. The invention further provides a composite suspending agent based on the cotton bollworm nuclear polyhedrosis virus WV104, the composite suspending agent has the characteristics of ultraviolet resistance, high adhesiveness, long lasting period, greenness, health and environmental protection, the prevention effect of the composite suspending agent for preventing and treating oriental tobacco budworms in the field reaches 78% or above, and the composite suspending agent has good application and popularization prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of pest control, and in particular relates to a cotton bollworm nuclear polyhedrosis virus WV104, a composite suspension and an application thereof. Background Art

[0002] As an important component of biological pesticides, insect virus insecticides have received extensive attention and application in recent years, among which nuclear polyhedrosis baculovirus and granulovirus are the most widely used. Viral insecticides play an important role in preventing and controlling agricultural and forestry pests and diseases with their green and environmentally friendly, safe for humans and animals, and no residue.

[0003] The cotton bollworm nuclear polyhedrosis virus (HaNPV) is a pathogenic microorganism that has a specific killing effect on cotton bollworms. The virus enters the body of the pest through feeding, replicates and proliferates in large quantities in the pest, and causes the death of the pest. Compared with other chemical pesticides and biological pesticides, the cotton bollworm nuclear polyhedrosis virus has the advantages of good control effect, long-lasting efficacy, and no toxic side effects on other organisms. It is one of the ideal biological pesticides.

[0004] Tobacco budworm is an important agricultural pest, and its damage is mainly manifested in the following three points. 1. Tobacco damage: Before tobacco buds appear, tobacco budworms will damage new buds and tender leaves, causing small holes or notches, and the holes will increase as the leaves grow. In severe cases, they can almost eat up the entire leaf. During the vigorous growth period of tobacco, tobacco budworms will focus on damaging the top heart buds and tender leaves of tobacco, forming window spots, holes, notches and headless seedlings. When tobacco plants are severely damaged, only the veins may remain on the leaves. In tobacco seed fields, tobacco budworms will also damage buds and flowers and fruits, and sometimes they can drill into tender stems to feed, causing the upper young buds and tender leaves to die. 2. Pepper damage: When tobacco budworms damage peppers, the entire larvae will drill into the fruit, eat the peel and placenta, and silken the fruit, leaving a large amount of feces, making the fruit inedible. 3. Damage to other crops: Tobacco budworm is an omnivorous pest that harms a wide range of hosts. In addition to tobacco and peppers, it can also harm many families of crops, including corn, sorghum, sunflowers, vetch, peas, cabbage, pumpkin and cotton.

[0005] In general, tobacco budworm is a serious pest that poses a threat to many crops and requires effective prevention and control measures.

[0006] In recent years, with the in-depth study of cotton bollworm nuclear polyhedrosis virus, it was found that the virus also has a strong killing effect on tobacco budworm. Cotton bollworm and tobacco budworm belong to the same order of Lepidoptera, and have certain similarities in ecological habits and life cycles. Therefore, cotton bollworm nuclear polyhedrosis virus has broad application prospects in the prevention and control of tobacco budworm. Summary of the invention

[0007] The purpose of the present invention is to develop highly effective insect virus pesticides and biological control of pests.

[0008] To this end, the present invention provides a cotton bollworm nuclear polyhedrosis virus HaNPV-WV104 ( Helicoverpa armigera nucleopolyhedrovirus HaNPV-WV104), the cotton bollworm nuclear polyhedrovirus WV104 was deposited in the China Center for Type Culture Collection on June 6, 2024, with the deposit address being Wuhan University, Wuhan, China, and the deposit number being CCTCC NO: V202461.

[0009] Specifically, the cotton bollworm nuclear polyhedrosis virus WV104 can be used to prepare tobacco budworm insecticide.

[0010] A composite suspension concentrate is characterized by comprising, by mass percentage, 0.2% to 3% of cotton bollworm nuclear polyhedrosis virus WV104 stock drug, 17.2% to 45% of Bacillus thuringiensis raw powder, and the balance being deionized water.

[0011] Specifically, the content of cotton bollworm nuclear polyhedrosis virus WV104 in the cotton bollworm nuclear polyhedrosis virus WV104 stock drug is 1×10 10 -2×10 11 PIB / mL.

[0012] Specifically, the Bacillus thuringiensis suspension having a Bacillus thuringiensis content of 50,000-70,000 IU / μg in the Bacillus thuringiensis raw powder is dried to a moisture content of ≤5.0%.

[0013] Specifically, the composite suspension further includes 0.5%-3% wetting agent, 2%-3% dispersant, 3%-10% synergist, 0.2%-2% stabilizer, 0.02%-0.5% food attractant, and 0.5%-1.5% thickener.

[0014] Specifically, the wetting agent includes at least one of butanol polyoxyethylene propylene ether, sodium salt of fatty alcohol ether sulfate, and disodium salt of AEO succinate.

[0015] Specifically, the dispersant includes at least one of modified polyacrylic acid copolymer, octylphenol polyoxyethylene ether sulfate, maleic acid / olefin copolymer sodium salt, and polyoxyethylene polyoxypropylene block copolymer.

[0016] Specifically, the above-mentioned enhancer includes at least one of polyglycerol fatty acid ester, rapeseed oil ethanol phthalamide polyoxyethylene ether, monoalkyl ether citrate disodium salt, and octadecyl phosphate.

[0017] Specifically, the stabilizer includes at least two of ascorbyl palmitate, ethoxyquinoline, thiodipropionic acid, nano titanium dioxide, and 2-hydroxy-4-methoxybenzophenone.

[0018] Specifically, the above-mentioned food attractant includes at least one of fruit acid, egg yolk powder and honey.

[0019] Specifically, the thickener includes at least one of magnesium aluminum silicate, bentonite, sodium alginate, and polyacrylic acid PAA.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1. The cotton bollworm nuclear polyhedrosis virus WV104 provided by the present invention is separated from insect corpses, and the viral gene sequence is identified as a new cotton bollworm nuclear polyhedrosis virus strain, which has the advantages of a wide insecticidal spectrum and high toxicity, and has good insecticidal activity against various lepidopteran pest larvae. It has a good control effect on tobacco budworms, can significantly reduce the degree of harm of tobacco budworms, improve crop yield and quality, and is harmless to the environment and human health, meets the requirements of green agricultural development, and is of great significance for the development of efficient insect virus pesticides and biological control of pests. In addition, the artificial breeding technology of cotton bollworm nuclear polyhedrosis virus host insects is mature, which can meet the large-scale production of insect viruses.

[0022] 2. The suspension concentrate provided by the present invention has the characteristics of UV resistance, strong adhesion and long lasting effect through optimized formula. It also has the characteristics of green, healthy and environmentally friendly biological pesticides. The control effect of the suspension concentrate for tobacco budworm in the field reaches more than 78%, and it has good application and promotion prospects.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The invention provides a developmental tree of cotton bollworm nuclear polyhedrosis virus WV104.

[0025] Figure 2 yes Figure 1 A partial enlarged view of the boxed part. DETAILED DESCRIPTION

[0026] The technical scheme in the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Although the representative embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the embodiments, but should be limited by the attached claims and their equivalents.

[0027] The effects of the cotton bollworm nuclear polyhedrosis virus WV104, the composite suspension concentrate and the application of the present invention are studied by means of specific examples.

[0028] Embodiment 1:

[0029] 1. Virus isolation and purification

[0030] The cotton bollworm nuclear polyhedrosis virus strain in the embodiment of the present invention was isolated from the dead bodies of diseased cotton bollworms in the field in Wuhan City, Hubei Province. A certain number of dead bodies were collected, placed in a centrifuge tube and shaken at high speed, an appropriate amount of ion buffer was added, mixed thoroughly, centrifuged to obtain the supernatant, resuspended and repeated the above centrifugation operation until a relatively pure polyhedron was obtained, which was stored at 4°C.

[0031] 2. Virus proliferation

[0032] The cotton bollworms collected from the wild are gradually domesticated into indoor strains through the gradual replacement method of pure vegetable feeding → half vegetable and half artificial feed → all artificial feed.

[0033] When 80% of the larvae have grown to the third instar, the purified toxin seed (which must not contain foreign bacteria) is diluted to a concentration of 1.0×10 4 -1.0×10 7 Mix the virus solution of 1000 PIB / ml with the feed and feed. Start observing after 3 days of feeding the virus feed. When the cotton bollworm body swells and the abdomen turns red, start collecting dead and dying worms. Collect them once in the morning and evening until all are collected. Beat the worm carcasses into a slurry and add an appropriate amount of deionized water for storage.

[0034] Virus separation and purification method: Take 1 mL of dead virus worm pulp and add 4 mL of distilled water, shake and mix; centrifuge at 500×r for 5 minutes, remove the supernatant into a new centrifuge tube; add 4 mL of distilled water, centrifuge at 4000×r for 20 minutes, discard the supernatant; repeat the above steps until no impurities can be seen by the naked eye. The precipitate is the purified virus. Store at 4℃.

[0035] 3. Genome extraction

[0036] Take 1.0g or 1.0mL of the sample, place it in a 100mL centrifuge tube, add 99.0mL of distilled water, and oscillate on an oscillator for 1min. Take 300μg of the suspension after oscillation in a centrifuge tube, add 100μg of 3× alkaline lysis solution, and place it in a 37℃ water bath for 30min. Remove the tube and add 200 μg Tris·HCl buffer, centrifuge at 10,000×g for 8 min, remove the supernatant, add 5 μg proteinase K and 60 μg SDS, then place in a 65°C water bath for 2 h, remove and cool to room temperature, add 650 μg Tris-saturated phenol and mix evenly, centrifuge at 10,000×g for 5 min, remove the supernatant and place it in a new centrifuge tube, add 650 μg phenol: chloroform (1:1) and mix evenly, centrifuge at 10,000×g for 5 min, remove the supernatant and place it in a new centrifuge tube, add 650 μg chloroform: isoamyl alcohol (24:1) and mix evenly, centrifuge at 10,000×g for 5 min, remove the supernatant and place it in a new centrifuge tube, determine the DNA concentration with a UV spectrophotometer, and place at 4°C for later use.

[0037] 4. Genome sequence analysis

[0038] The full length of the genome sequence of WV104 strain is 131404bp, which is lower than that of HaNPV-G4 strain (131405bp) and higher than that of HaNPV-DJ0031 strain (129801bp); the GC content is 39%, which is higher than that of G4 strain (38.1%) and DJ0031 strain (38.9%). The 38 core genes of baculovirus were analyzed by multi-gene joint phylogeny using MEGA7. The results are as follows: Figure 1 As shown, the virus strain was found to belong to the family Baculoviridae, genus Alphabaculovirus, group II, and was a new strain of cotton bollworm nuclear polyhedrosis virus. The strain was named cotton bollworm nuclear polyhedrosis virus WV104 and was deposited in the China Center for Type Culture Collection on June 6, 2024, with the deposit number CCTCCNO: V202461.

[0039] Embodiment 2:

[0040] This example studies the effect of cotton bollworm nuclear polyhedrosis virus on the indoor biological activity of tobacco budworm.

[0041] 1. Test subjects

[0042] The third instar larvae of tobacco budworm were cultured continuously in the laboratory.

[0043] 2. Test reagents

[0044] 10 billion PIB / ml cotton bollworm nuclear polyhedrosis virus WV104 wettable powder, 50,000 IU / microgram Bacillus thuringiensis wettable powder.

[0045] 3. Test methods

[0046] Preparation of drugs: Weigh cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis drugs respectively, dilute them with sterile water to make mother liquor, and then dilute the mother liquor into single drugs A and B with a certain concentration gradient according to the preliminary experimental results. Compositions C, D, and E are prepared by first diluting mother liquor A to a final concentration of 1×10 5 , 1×10 4 , 1×10 3 , 1×10 2 , 1×10PIB / ml, and then diluted the mother solution B and added it to the five dilutions to make the final concentrations of 20IU / μg, 30IU / μg and 40IU / μg; for the compositions F and G, the mother solution B was first diluted to make the final concentrations of 20, 10, 5, 2.5, and 1.25IU / μg, and then the mother solution A was diluted and added to the five dilutions to make the final concentrations of 2×10 5 PIB / mL and 3×10 5 PIB / ml. The specific concentration configuration is shown in Table 1, where A is cotton bollworm nuclear polyhedrosis virus WV104 and B is Bacillus thuringiensis. Sterile water treatment was set as a blank control.

[0047] Table 1 Test dose settings

[0048]

[0049]

[0050]

[0051]

[0052] Using the leaf dipping method, the tobacco leaves were immersed in the liquid for 10 seconds, dried naturally, and placed in a culture dish. Cotton balls soaked in clean water were placed in the dish to keep the moisture, and finally the third-instar larvae of tobacco budworms were inoculated. Thirty worms were used for each treatment, with four replicates. The tobacco budworms were raised in an artificial climate chamber, and the number of live worms was counted after 120 hours and 168 hours.

[0053] 4. Data processing

[0054] Mortality rate (%) = number of dead insects / total number of insects treated × 100

[0055] Corrected mortality rate (%) = (treatment mortality rate - control mortality rate) / (1 - control mortality rate)

[0056] Regression analysis was performed on the logarithmic values ​​of drug concentrations and the corrected mortality rate, the LC50 of each treatment agent was calculated, the co-toxicity coefficient (CTC value) of the mixture was calculated, and the co-toxicity coefficient (CTC value) in the results was used to evaluate the synergistic effect of the agents.

[0057] Co-toxicity coefficient (CTC) = (LC of a single dose of a standard drug 50 / LC of standard reagent in mixture 50 )×100

[0058] When the co-toxicity coefficient is greater than 120, it indicates a synergistic effect.

[0059] 5. Statistical analysis

[0060] The co-toxicity coefficients under each drug treatment were statistically analyzed, and the results are shown in Table 2.

[0061] Table 2 Results of indoor bioactivity determination of tobacco budworm

[0062]

[0063] As shown in Table 2, the combined treatment of Bacillus thuringiensis (20, 30, 40 IU / μg) and H. armigera nuclear polyhedrosis virus against tobacco budworm LC 50 The values ​​were 929.64, 896.52 and 794.37 PIB / mL respectively, with the formula of 1×10 5 PIB / ml+60IU / μg has the highest activity.

[0064] Helicoverpa armigera nuclear polyhedrosis virus (1×10 4 , 2×10 4 PIB / ml) and Bacillus thuringiensis combined treatment against cotton bollworm LC50 were 2.63 and 1.55 IU / μg, respectively. 5 PIB / ml+20IU / μg has the highest activity.

[0065] When cotton bollworm nuclear polyhedrosis virus and Bacillus thuringiensis were combined, the co-toxicity coefficients against tobacco budworm were all greater than 120 in the five formulations, showing a synergistic effect.

[0066] Considering the indoor bioassay data and production cost, we chose 1×10 7 PIB / ml Helicoverpa armigera nuclear polyhedrosis virus, 2000IU / μg Bacillus thuringiensis for production.

[0067] Embodiment 3:

[0068] In this example, field experiments were conducted in Henan to study the inhibitory effects of cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis on tobacco budworm.

[0069] 1. Test reagents

[0070] The cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis composite suspension comprises, by mass percentage, 1% cotton bollworm nuclear polyhedrosis virus WV104 mother drug, 30% Bacillus thuringiensis original powder, 1.5% wetting agent, 2% dispersant, 10% synergist, 1.5% stabilizer, 0.1% food attractant, 0.5% thickener, and the balance is deionized water. Among them, the cotton bollworm nuclear polyhedrosis virus WV104 content is 1×10 7 PIB / ml; Bacillus thuringiensis content is 2000IU / microgram; the wetting agent is sodium salt of fatty alcohol ether sulfate, the dispersant is polyoxyethylene polyoxypropylene block copolymer, the enhancer is polyglycerol fatty acid ester, the stabilizer includes ascorbyl palmitate and thiodipropionic acid in a mass ratio of 1:2, the attractant is fruit acid, and the thickener is sodium alginate.

[0071] 1 billion PIB / ml cotton bollworm nuclear polyhedrosis virus wettable powder, 16000IU / microgram Bacillus thuringiensis wettable powder.

[0072] 2. Test environment

[0073] The experiment was conducted at the tobacco planting base in Linying County, Luohe City, Henan Province. The crop in the experimental field was tobacco. The tillage management, soil conditions and growth conditions of the experimental field were relatively consistent. The terrain was relatively flat, and tobacco budworms occurred all year round, which met the test requirements.

[0074] 3. Test methods

[0075] The plots are arranged in random blocks, with a plot area of ​​4m*5m=20m 2 There were 6 treatments in the experimental area (Table 3), each treatment was repeated 4 times, with a total of 24 plots. Isolation areas were set between the plots, and protection rows were set around the experimental field.

[0076] Table 3 Experimental design of test drugs

[0077]

[0078] 3.1 Period and method of use

[0079] Apply the pesticide during the peak hatching period of tobacco budworm eggs, spray evenly from low concentration to high concentration one by one at a uniform speed, without repeated spraying or missing any spots.

[0080] 3.2 Usage capacity and preparation of medicine

[0081] Water consumption is 750L / hm 2 , each cell (20m 2 ) Theoretical water consumption is 1.5L, actual water consumption is 1.65L.

[0082] 4. Data processing

[0083] Pest reduction rate (%) = (number of insects before application - number of insects after application) / number of insects before application × 100

[0084] Control effect (%) = (insecticidal population reduction rate in the treated area - insecticidal population reduction rate in the blank control area) / (100 - insecticidal population reduction rate in the blank control area) × 100

[0085] The experimental results are shown in Table 4, where lowercase and uppercase letters indicate significant differences at the 0.05 and 0.01 levels, respectively.

[0086] Table 4 Field test results of tobacco budworm

[0087]

[0088]

[0089]

[0090] Five days after the second application, the results of the investigation on the control effect of tobacco budworm (Table 4) showed that the composite suspension of the tested substance 100, 200, 400mL / 667m 2 The control efficacy of the treatments against tobacco budworms was 65.20%, 68.72% and 71.20% respectively, compared with the control of 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200g / 667m2 and 16000IU / mg Bacillus thuringiensis wettable powder 200g / 667m 2 The control effects of the treatments were 67.15% and 70.82% respectively. The statistical analysis results showed that the composite suspension of the tested substance 100mL / 667m 2 and 400mL / 667m 2 There were significant differences among the treatments; the composite suspension of the tested substance was 400mL / 667m 2 Treatment and control 1 billion PIB / g Helicoverpa armigera nuclear polyhedrosis virus wettable powder 200g / 667m 2 There was a significant difference in the treatment; the test compound suspension 100mL / 667m 2 Treatment and control 16000IU / mg Bacillus thuringiensis WP 200g / 667m 2 There were significant differences in the treatments.

[0091] 20 days after the second application, the results of the investigation on the control effect of tobacco budworm (Table 4) showed that the composite suspension of the tested substance 100, 200, 400mL / 667m 2 The control efficacy of the treatments against tobacco budworms was 74.50%, 76.44% and 82.90% respectively, and the control was 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200g / 667m 2and 16000IU / mg Bacillus thuringiensis wettable powder 200g / 667m 2 The control effects of the treatments were 75.97% and 75.51% respectively. The statistical analysis results showed that the composite suspension of the tested substance 100 and 200 mL / 667m 2 And the test substance composite suspension 400mL / 667m 2 There were significant differences among the treatments; the test compound suspension 400m / 667m 2 Treatment and control 1 billion PIB / g Helicoverpa armigera nuclear polyhedrosis virus wettable powder 200g / 667m 2 , 16000IU / mg Bacillus thuringiensis wettable powder 200g / 667m 2 There were significant differences in the treatments.

[0092] The test results show that the composite suspension has a significant control effect on tobacco budworms. The control effect is obvious 5 days after application, and the control effect 20 days after application shows that the insect virus has good persistence and is safe for tobacco. Spray it during the peak hatching period of tobacco budworm eggs, apply the pesticide twice in total, and use 750L / hm 2 . Recommended dosage: 100-400mL / 667m 2 .

[0093] Embodiment 4:

[0094] In this example, field experiments were conducted in Shandong to study the inhibitory effects of cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis on tobacco budworm.

[0095] 1. Test reagents

[0096] The cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis composite suspension comprises, by mass percentage, 1% cotton bollworm nuclear polyhedrosis virus WV104 mother drug, 30% Bacillus thuringiensis original powder, 1.5% wetting agent, 2% dispersant, 10% synergist, 1.5% stabilizer, 0.1% food attractant, 0.5% thickener, and the balance is deionized water. Among them, the cotton bollworm nuclear polyhedrosis virus WV104 content is 1×10 7 PIB / ml; Bacillus thuringiensis content is 2000IU / microgram; the wetting agent is sodium salt of fatty alcohol ether sulfate, the dispersant is polyoxyethylene polyoxypropylene block copolymer, the enhancer is polyglycerol fatty acid ester, the stabilizer includes ascorbyl palmitate and thiodipropionic acid in a mass ratio of 1:2, the attractant is fruit acid, and the thickener is sodium alginate.

[0097] 1 billion PIB / ml cotton bollworm nuclear polyhedrosis virus wettable powder, 16000IU / microgram Bacillus thuringiensis wettable powder.

[0098] 2. Test environment

[0099] Xiyuliang Village, Taihe Town, Zibo City, Shandong Province. Soil type: medium loam, organic matter 1.18%, good fertilizer and water conditions, consistent management measures.

[0100] 3. Test methods

[0101] The plots are arranged in random blocks, with a plot area of ​​30m 2 There were 6 treatments in the experimental area (Table 5), each treatment was repeated 4 times, with a total of 24 plots. Isolation areas were set between the plots, and protection rows were set around the experimental field.

[0102] Table 5 Experimental design of test drugs

[0103]

[0104] Spray the whole plant evenly. When applying the pesticide, apply the pesticide one by one in the order of blank control, low dose of test pesticide to high dose, and control pesticide. Wash the sprayer carefully before changing the pesticide. The pesticide solution is prepared by the secondary dilution method to ensure uniform preparation of the pesticide solution.

[0105] 4. Data processing

[0106] Pest reduction rate (%) = (number of insects before application - number of insects after application) / number of insects before application × 100

[0107] Control effect (%) = (insecticidal population reduction rate in the treated area - insecticidal population reduction rate in the blank control area) / (100 - insecticidal population reduction rate in the blank control area) × 100

[0108] 5. Results and Analysis

[0109] The control effect 3 days after the first application is shown in Table 6. In the table, completely different lowercase letters indicate significant differences between treatments (p<0.05), and completely different uppercase letters indicate extremely significant differences between treatments (p<0.01). As shown in Table 6, the average control effects of the three doses of the test agent composite suspension 100 ml / mu, 200 ml / mu, and 400 ml / mu were 51.92%, 58.54%, and 62.88%, respectively, and there was no significant difference between adjacent doses. The average control effect of the test agent composite suspension 100 ml / mu was similar to that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu and the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, and the difference was not significant. The average control effect of the experimental agent composite suspension at a dosage of 200 ml / mu was higher than that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder at a dosage of 200 g / mu, with a significant difference; the control effect was similar to that of the control agent 16000IU / mg Bacillus thuringiensis wettable powder at a dosage of 200 g / mu, with no significant difference. The average control effect of the experimental agent composite suspension at a dosage of 400 ml / mu was higher than that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder at a dosage of 200 g / mu, with an extremely significant difference; the control effect was similar to that of the control agent 16000IU / mg Bacillus thuringiensis wettable powder at a dosage of 200 g / mu, with no significant difference.

[0110] Table 6 Control effect of composite suspension 3 days after the first application

[0111]

[0112]

[0113] The control effect 10 days after the first application is shown in Table 7. The average control effects of the three doses of the test agent composite suspension 100 ml / mu, 200 ml / mu, and 400 ml / mu were 77.32%, 83.58%, and 88.50%, respectively, and there was no significant difference between adjacent doses. The average control effect of the test agent composite suspension 100 ml / mu was lower than that of the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, with a significant difference; and the control effect was similar to that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu, with no significant difference. The control efficacy of the experimental agent composite suspension at a dosage of 200 ml / mu was similar to that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu and the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, with no significant difference. The average control efficacy of the experimental agent composite suspension at a dosage of 400 ml / mu was higher than that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu, with a significant difference; the control efficacy was similar to that of the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, with no significant difference.

[0114] Table 7 Control effect of composite suspension 10 days after the first application

[0115]

[0116]

[0117] The control effect 10 days after the second application is shown in Table 8. The average control effect of the three doses of the test agent composite suspension concentrate 100 ml / mu, 200 ml / mu, and 400 ml / mu were 81.78%, 89.79%, and 94.46%, respectively. The average control effect of the test agent composite suspension concentrate 400 ml / mu was higher than that of the 100 ml / mu dose, and the difference was significant; the difference between the other agent doses was not significant.

[0118] Table 8 Control effect of composite suspension 10 days after the second application

[0119]

[0120] The control effect 20 days after the second application is shown in Table 9. The average control effects of the three doses of the test agent composite suspension 100 ml / mu, 200 ml / mu, and 400 ml / mu were 74.48%, 84.82%, and 89.17%, respectively. Among them, the average control effects of the two doses of 200 ml / mu and 400 ml / mu were higher than that of the 100 ml / mu dose, and the differences were significant and extremely significant, respectively. The average control effect of the test agent composite suspension 100 ml / mu was lower than that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu and the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, and the differences were extremely significant and significant, respectively. The average control effect of the experimental agent composite suspension at a dosage of 200 ml / mu was similar to that of the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu and the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, with no significant difference. The average control effect of the experimental agent composite suspension at a dosage of 400 ml / mu was higher than that of the control agent 16000 IU / mg Bacillus thuringiensis wettable powder 200 g / mu, with a significant difference, and was similar to the control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder 200 g / mu, with no significant difference.

[0121] Table 9 Control effect of composite suspension 20 days after the second application

[0122]

[0123]

[0124] The results of the investigation on the control effect 3 days and 10 days after the first application and 10 days and 20 days after the second application showed that the composite suspension agent had a good control effect on tobacco budworms. 20 days after the second application, the average control effects of the three doses of 100 ml / mu, 200 ml / mu and 400 ml / mu were 74.48%, 84.82% and 89.17% respectively, with rapid effect and long lasting effect.

[0125] Based on the results of one year of experiments, the preliminary recommended dosage of the experimental compound suspension for controlling tobacco budworms is 200-400 ml / mu. Spray the whole plant evenly during the peak hatching period of tobacco budworm eggs. Apply the pesticide twice in a row with an interval of 10 days.

[0126] Embodiment 5:

[0127] In this example, field experiments were conducted in Sichuan to study the inhibitory effects of cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis on tobacco budworm.

[0128] 1. Test reagents

[0129] The cotton bollworm nuclear polyhedrosis virus WV104 and Bacillus thuringiensis composite suspension comprises, by mass percentage, 1% cotton bollworm nuclear polyhedrosis virus WV104 mother drug, 30% Bacillus thuringiensis original powder, 1.5% wetting agent, 2% dispersant, 10% synergist, 1.5% stabilizer, 0.1% food attractant, 0.5% thickener, and the balance is deionized water. Among them, the cotton bollworm nuclear polyhedrosis virus WV104 content is 1×10 7 PIB / ml; Bacillus thuringiensis content is 2000IU / microgram; the wetting agent is sodium salt of fatty alcohol ether sulfate, the dispersant is polyoxyethylene polyoxypropylene block copolymer, the enhancer is polyglycerol fatty acid ester, the stabilizer includes ascorbyl palmitate and thiodipropionic acid in a mass ratio of 1:2, the attractant is fruit acid, and the thickener is sodium alginate.

[0130] 1 billion PIB / ml cotton bollworm nuclear polyhedrosis virus wettable powder, 16000IU / microgram Bacillus thuringiensis wettable powder.

[0131] 2. Test environment

[0132] Caomiao Village, Qingzhu Subdistrict Office, Qingshen County, Meishan City, Sichuan Province. Soil type is brown-gray semi-sandy soil, with 1.7% organic matter, pH 5.8, and medium fertility level.

[0133] 3. Test methods

[0134] The plots are arranged in random blocks, with a plot area of ​​15m 2 There were 6 treatments in the experimental area (Table 3), each treatment was repeated 4 times, with a total of 24 plots. Isolation areas were set between the plots, and protection rows were set around the experimental field.

[0135] Table 10 Test design of test agents

[0136]

[0137] Crop: Tobacco, Variety: Green Pole. When applying the pesticide for the first time, when tobacco is in the mature stage and tobacco budworm eggs are in the peak hatching period, the solution is prepared by the secondary dilution method and sprayed evenly with a sprayer.

[0138] 4. Data processing

[0139] Pest reduction rate (%) = (number of insects before application - number of insects after application) / number of insects before application × 100

[0140] Control effect (%) = (insecticidal population reduction rate in the treated area - insecticidal population reduction rate in the blank control area) / (100 - insecticidal population reduction rate in the blank control area) × 100

[0141] 5. Results and Analysis

[0142] Table 11 Control effect of composite suspension

[0143]

[0144]

[0145] The data in Table 11 are the average values ​​of 4 replicates, and the variance analysis was processed by DPS (v7.05 version). Letters indicate significant differences (uppercase 0.01 level, lowercase 0.05 level, DMRT method)

[0146] The composite suspension was used at 100, 200, and 400 ml per mu to control tobacco budworms. The efficacy was 48.4%, 52.5%, and 53.4% ​​three days after the first application, 75.3%, 79.2%, and 81.5% ten days after the second application, and 65.3%, 75.4%, and 78.7% twenty days after the second application. The control agent 16000 IU / mg Bacillus thuringiensis wettable powder was used at 200 g per mu. The efficacy was 43%, 72.2%, and 64.8% three days after the first application, 10 days after the second application, and 20 days after the second application. The control agent 1 billion PIB / g cotton bollworm nuclear polyhedrosis virus wettable powder was used at 200 g per mu. The efficacy was 46.2%, 73.5%, and 71.3% three days after the first application, 10 days after the second application, and 20 days after the second application. The statistical data of the protective efficacy 10 days after the second application of the drug were used for variance analysis. There was no significant difference in the protective efficacy of each dose of the test agent. Compared with the control agent, the protective efficacy of each dose of the test agent was equivalent to that of the two groups of control agents.

[0147] The test results show that the control effect of the composite suspension agent on tobacco budworms increases with the increase of dosage. The dosage of 100 ml per mu is slightly lower, and the control effect of 200 or 400 ml per mu is 52.5-53.4% ​​three days after the first application, and the rapid effect is relatively slow. The control effect is 79.2-81.5% 10 days after the second application, and the insect quantity is controlled below 4.5 heads / 20 plants, which is lower than the insect quantity of 18.0 heads / 20 plants in the clear water control, which reduces the occurrence of tobacco budworms and has a good control effect; 20 days after the second application, the control effect remains above 75.4%, showing good persistence.

[0148] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A cotton bollworm nuclear polyhedrosis virus WV104, characterized in that: The cotton bollworm nuclear polyhedrosis virus WV104 was deposited in the China Center for Type Culture Collection in June 2024, with the deposit number CCTCC NO: V202461.

2. Use of the cotton bollworm nuclear polyhedrosis virus WV104 as claimed in claim 1 in the preparation of tobacco budworm insecticide.

3. A composite suspension, characterized in that: The invention comprises, by mass percentage, 0.2% to 3% of cotton bollworm nuclear polyhedrosis virus WV104 parent drug, 3.6% to 22.5% of Bacillus thuringiensis raw powder, and the balance is deionized water.

4. The composite suspension according to claim 3, characterized in that: The content of cotton bollworm nuclear polyhedrosis virus WV104 in the cotton bollworm nuclear polyhedrosis virus WV104 masterbatch is 1×10 10 -2×10 11 PIB / mL.

5. The composite suspension according to claim 3, characterized in that: The Bacillus thuringiensis raw powder has a Bacillus thuringiensis content of 50,000-70,000 IU / μg.

6. The composite suspension according to claim 3, characterized in that: It also includes 0.5%-3% wetting agent, 2%-3% dispersant, 3%-10% synergist, 0.2%-2% stabilizer, 0.02%-0.5% food attractant, and 0.5%-1.5% thickener.

7. The composite suspension according to claim 6, characterized in that: The wetting agent includes at least one of butanol polyoxyethylene propylene ether, sodium salt of fatty alcohol ether sulfate, and disodium salt of AEO succinate.

8. The composite suspension according to claim 6, wherein: The dispersant includes at least one of modified polyacrylic acid copolymer, octylphenol polyoxyethylene ether sulfate, maleic acid / olefin copolymer sodium salt, and polyoxyethylene polyoxypropylene block copolymer.

9. The composite suspension according to claim 6, characterized in that: The synergist includes at least one of polyglycerol fatty acid ester, rapeseed oil ethanol phthalamide polyoxyethylene ether, monoalkyl ether citrate disodium salt, and octadecyl phosphate.

10. Use of the composite suspension concentrate as claimed in any one of claims 3 to 9 in controlling tobacco budworms.

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