Compound insecticide of emamectin benzoate and lufenuron

Abstract

The invention relates to the technical field of pesticide compounding, in particular to a compound pesticide of emamectin benzoate and lufenuron, which comprises the active ingredients of emamectin benzoate and lufenuron. The synergistic effect is evaluated through the co-toxicity coefficient (CTC), when the CTC is larger than or equal to 120, it is judged that the synergistic effect is remarkable, the mass ratio of the preferable effective components is 2: 1, 1: 1, 1: 2, 1: 3 or 1: 4, the optimal effect is shown according to the ratio of 1: 2, the co-toxicity coefficient reaches 160.56, liquid medicine with the concentration gradient of 2.4 mg / L, 1.2 mg / L, 0.6 mg / L, 0.3 mg / L and 0.15 mg / L is adopted in a test, and spraying is conducted through a Potter spray tower at the liquid spraying amount of 1 mL and the pressure of 1.47 * 10 < 5 > Pa. The LC50 value of the compound insecticide for citrus phyllocoptruta oleivora is 0.23-0.45 mg / L, and the LC90 value is 2.42-3.40 mg / L, which indicates that the efficient control effect can be realized at a lower concentration, the pesticide dosage is reduced, and the environmental pollution risk is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticide compounding, in particular to a kind of emamectin benzoate and lufenuron compound insecticide. BACKGROUND

[0002] At present, chemical control is still the main means to control citrus rust mite, and the commonly used single agent includes emamectin benzoate (referred to as "emamectin benzoate") and lufenuron. Emamectin benzoate is a highly effective semi-synthetic antibiotic insecticide, which interferes with nerve conduction by acting on GABA receptors of pests, has strong and high toxicity to mites, but the effective period is short (usually 7-10 days), and long-term single use can easily lead to rapid increase of pest resistance; Lufenuron is a benzoyl urea insecticide, which blocks the molting process by inhibiting chitin synthesis of pests, has outstanding effect on juvenile mites and eggs, and has long effective period (15-20 days), but has poor quick-acting property and limited effect on adult mites.

[0003] In the prior art, there are significant defects in single-agent control of citrus rust mite:

[0004] Resistance problem: Long-term dependence on single agent leads to increasing resistance of rust mite year by year, for example, the field control concentration of emamectin benzoate has increased from 0.5 mg / L in the early stage to more than 2 mg / L, which increases the control cost and reduces the effect.

[0005] Insufficient complementary effect: The "quick-acting property" of emamectin benzoate and the "long-acting property" of lufenuron cannot be considered together, and it is difficult to achieve the synergistic effect of "rapid pest control + long-term protection";

[0006] Lack of scientific compounding scheme: Although some studies have tried to compound the two, there is a lack of systematic ratio screening and quantitative evaluation:

[0007] The best compounding ratio (such as 2:1, 1:1, 1:2, etc.) is not clear, resulting in unstable compounding effect;

[0008] Lack of synergistic verification based on co-toxicity coefficient (CTC), which cannot scientifically determine whether there is synergistic effect (CTC≥120 for synergism);

[0009] The toxicity parameters (such as LC 50 , LC 90 ) and applicable concentration range (such as 0.15-2.4 mg / L) after compounding are not clear, which makes it difficult to guide precise pesticide application in the field.

[0010] In addition, the existing compounding technology has deficiencies in standardization of test methods, such as non-standardized spraying conditions (such as spraying facilities, spraying restrictions), non-standardized environmental parameter adjustment, and non-standardized death determination criteria (body color turning brown and shriveling), which leads to poor repeatability of test results and cannot provide reliable basis for actual application. SUMMARY

[0011] (I) Technical problems solved

[0012] In view of the deficiencies in the prior art, the present application provides a compounded insecticide of emamectin benzoate and lufenuron.

[0013] (II) Technical solutions

[0014] To achieve the above-mentioned object, the present application provides the following technical solutions: a compounded insecticide of emamectin benzoate and lufenuron, which comprises a compounded insecticide, the active ingredients of the compounded insecticide comprising emamectin benzoate and lufenuron, the compounded insecticide being used for preventing and treating citrus rust mites, and the compounded insecticide being evaluated for synergistic effect by using a co-toxicity coefficient (CTC), and being determined to have synergistic effect when CTC≥120.

[0015] Preferably, the mass ratio of the effective ingredients of emamectin benzoate and lufenuron is 2:1, 1:1, 1:2, 1:3 or 1:4.

[0016] Further preferably, the mass ratio of the effective ingredients is 1:2, and the co-toxicity coefficient of the compounded insecticide for citrus rust mites is 160.56.

[0017] Still preferably, the emamectin benzoate is a technical material with a purity≥95%, the lufenuron is a technical material with a purity≥97%, and a mother liquor is prepared by dissolving in acetone.

[0018] Preferably, the concentration gradient of the compounded insecticide in the test is 2.4, 1.2, 0.6, 0.3, 0.15 mg / L, and the test is performed by using a Potter spray tower to spray 1 mL of spray liquid at a pressure of 1.47×10 5 Pa.

[0019] Further preferably, the toxicity of the compounded insecticide is evaluated by using mortality and corrected mortality, and the calculation formula is as follows:

[0020] Mortality P1=(number of dead insects K / total number of insects N)×100%;

[0021] Corrected mortality P2=(treatment mortality P t -control mortality P0) / (1-P0)×100%.

[0022] Still preferably, the regression equation of the toxicity of the compounded insecticide is Y=a+bx, wherein the independent variable x is the logarithmic value of the concentration of the pesticide, the dependent variable y is the probability value of the corrected mortality, and the correlation coefficient r≥0.99.

[0023] Preferably, the co-toxicity coefficient (CTC) is calculated by the following formula:

[0024] Single dose toxicity index TI(A) = (standard LC 50 / agent ALC 50 ) x 100%;

[0025] Single dose toxicity index TI(B) = (standard LC 50 / agent BLC 50 ) x 100%;

[0026] Mixed agent theoretical toxicity index TTI = TI(A) x A proportion + TI(B) x B proportion;

[0027] Mixed agent actual toxicity index ATI = (standard LC 50 / mixed LC 50 ) x 100%;

[0028] CTC = (ATI / TTI) x 100%.

[0029] Further preferably, the LC 50 value of the complex insecticide for citrus rust mites is 0.23-0.45 mg / L, and the LC 90 value is 2.42-3.40 mg / L.

[0030] Again preferably, the test conditions of the complex insecticide are temperature (25±1)℃, light / darkness = 16h / 8h, the death rate investigation time of the test insects is 48h after application, and the judgment standard is that the body color becomes brown and shriveled, which is determined as death.

[0031] (III) Beneficial effects

[0032] Compared with the prior art, the present application provides a complex insecticide of emamectin benzoate and lufenuron, which has the following beneficial effects:

[0033] The technical solution is particularly suitable for preventing and treating citrus rust mites, and the synergistic effect is evaluated by the co-toxicity coefficient (CTC). When CTC≥120, it indicates that there is a significant synergistic effect. Preferably, the mass ratio of the effective components is 2:1, 1:1, 1:2, 1:3 or 1:4, of which the ratio of 1:2 shows the best effect, and the co-toxicity coefficient reaches 160.56.

[0034] The main beneficial effects are as follows:

[0035] Significant synergistic effect: under the preferred ratio, the complex insecticide shows obvious synergistic effect on citrus rust mites. Through the evaluation of the co-toxicity coefficient, it is determined that the best ratio is 1:2, and the CTC value is as high as 160.56, far exceeding the synergistic standard (CTC≥120), which proves its excellent control effect.

[0036] High efficiency and low concentration use: The test results show that the LC50 value of the complex insecticide on citrus red mite is 0.23-0.45 mg / L, and the LC90 value is 2.42-3.40 mg / L, indicating that high efficiency can be achieved at a lower concentration, reducing the amount of pesticide and reducing the risk of environmental pollution.

[0037] Accurate toxicity evaluation method: The Potter spray tower is used for spraying test, which ensures the consistency of experimental conditions and the reliability of results. The mortality and corrected mortality calculation formula, and the toxicity regression equation Y=a+bx are used to accurately evaluate the toxicity of the pesticide, and the correlation coefficient r is greater than or equal to 0.99, which ensures the high accuracy of the data.

[0038] High-quality raw materials guarantee: Aminomethylcyclohexane and mite mite are selected with purity of ≥95% and ≥97% respectively, which ensures the stability and efficiency of the pesticide. The method of dissolving the mother liquor in acetone further improves the uniformity and stability of the pesticide.

[0039] Wide applicability and flexibility: The complex insecticide is not only suitable for the prevention and control of citrus red mite, but also has wide applicability. Different effective component ratios can be selected according to different needs, and the use concentration can be flexibly adjusted to adapt to various application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The flowchart of the inventive complex insecticide is shown. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0042] Please refer to Figure 1 The complex insecticide of aminomethylcyclohexane and mite mite according to the present application comprises a complex insecticide, the active ingredients of the complex insecticide comprise aminomethylcyclohexane and mite mite, the complex insecticide is used for preventing and controlling citrus red mite, and the complex insecticide adopts a co-toxicity coefficient (CTC) to evaluate the synergistic effect, and is determined to have a synergistic effect when the CTC is greater than or equal to 120.

[0043] The technical scheme realizes efficient prevention and control of citrus red mite through the core mechanism of "different action mechanisms synergistic effect + scientific quantitative evaluation".

[0044] The active ingredient emamectin benzoate (a neurotoxic agent that interferes with the nerve conduction of pests) and lufenuron (a chitin synthesis inhibitor that inhibits the molting of pests) have complementary action mechanisms, and after compounding, the toxicity to citrus red mites is enhanced through synergistic action.

[0045] The synergistic effect is evaluated by using the coefficient of joint toxicity (CTC) as an index (CTC≥120 is determined to be synergistic), combined with mortality, corrected mortality, LC 50 / LC 90 quantitative parameters, and the toxicity and synergistic effect of the compound pesticide are scientifically verified to ensure that the control efficiency on citrus red mites is better than that of a single agent.

[0046] Active ingredient ratio and synergistic mechanism

[0047] Ratio selection (2:1, 1:1, 1:2, 1:3, 1:4):

[0048] Emamectin benzoate has strong rapid efficacy (quickly kills adult pests), but the effective period is short; lufenuron has a long effective period (inhibits larval development), but the rapid efficacy is weak. Different ratios can achieve "rapid efficacy + long-term efficacy" through adjusting the proportion of the two:

[0049] Low proportion of lufenuron (such as 2:1) focuses on rapid pest control, and high proportion of lufenuron (such as 1:4) focuses on long-term protection;

[0050] When the ratio of 1:2 is preferred, the coefficient of joint toxicity reaches 160.56 (the highest), and at this time, the synergistic effect of the two is the strongest - emamectin benzoate rapidly reduces the pest population base, and lufenuron inhibits the reproduction of subsequent populations, and the toxicity is superimposed, which is significantly better than that of a single agent (emamectin benzoate LC 50 = 0.22 mg / L, and lufenuron LC 50 = 0.94 mg / L).

[0051] Principle of calculating the coefficient of joint toxicity (CTC):

[0052] The synergistic effect of the compound pesticide is quantified by the formula:

[0053] The toxicity index TI(A) of a single agent = (standard agent LC 50 / agent A LC 50 ) × 100%;

[0054] The toxicity index TI(B) of a single agent = (standard agent LC 50 / agent B LC 50 ) × 100%;

[0055] The theoretical toxicity index TTI of the mixture = TI(A) × A proportion + TI(B) × B proportion;

[0056] The actual toxicity index ATI of the mixture = (standard agent LC 50 / mixture LC 50 ) x 100%;

[0057] Single-agent toxicity index TI (A / B): based on emamectin benzoate as standard, reflecting the toxicity of single agent (the higher the TI value, the stronger the toxicity);

[0058] Mixture theoretical toxicity index TTI: the theoretical synergistic value calculated based on the proportion of single agent;

[0059] Mixture actual toxicity index ATI: the synergistic value corresponding to the actual toxicity of mixture;

[0060] CTC = (ATI / TTI) x 100%: when CTC ≥ 120, it indicates that the toxicity after compounding exceeds the theoretical value, and there is significant synergism.

[0061] Purity of technical material and preparation of mother liquor

[0062] Purity of technical material (emamectin benzoate ≥ 95%, lufenuron ≥ 97%): high-purity technical material can reduce impurity interference and ensure stable effective ingredient content, providing a reliable basis for subsequent concentration gradient preparation and toxicity determination;

[0063] Preparation of mother liquor by acetone dissolution: acetone has good solubility for both kinds of technical materials and is easy to evaporate (no residual interference after spraying), and 1000 mg / L mother liquor is prepared by accurate weighing (emamectin benzoate 0.1053 g, lufenuron 0.1031 g) and constant volume (100 mL) to ensure the accuracy of subsequent dilution concentration.

[0064] Concentration gradient and spraying conditions

[0065] Concentration gradient (2.4, 1.2, 0.6, 0.3, 0.15 mg / L): by setting 5 concentrations through half-dilution method, covering the toxicity range from high to low, the relationship between concentration and mortality can be completely fitted, providing data support for calculating LC 50 / LC 90 ;

[0066] Potter spray tower spraying parameters: 1 mL of spray liquid ensures consistent dosage of pesticide, 1.47 x 10 5 Pa stable pressure ensures uniform droplet size (avoids errors caused by uneven spraying), and standardizes the dosage of pesticide contacted by test insects.

[0067] Toxicity evaluation index

[0068] Mortality and corrected mortality:

[0069] Mortality P1 directly reflects the killing proportion of pesticide on test insects;

[0070] When the control mortality is 5%-20%, the natural death interference is eliminated by correcting the mortality P2 to ensure the authenticity of the results (such as when the control mortality is 10% and the treatment mortality is 80%, the corrected mortality=(80%-10%) / (1-10%)≈77.78%).

[0071] Virulence regression equation (Y=a+bx):

[0072] Take the logarithmic value of the concentration of the pesticide (x) as the independent variable and the corrected mortality probability value (y) as the dependent variable, fit a linear equation (correlation coefficient r≥0.99), and reflect the quantitative relationship between concentration and virulence to calculate LC 50 / LC 90 Provide a mathematical model.

[0073] LC 50 And LC 90 :

[0074] LC 50 (0.23-0.45mg / L): the concentration that kills 50% of the test insects, the lower the value, the stronger the virulence of the pesticide;

[0075] LC 90 (2.42-3.40mg / L): the concentration that kills 90% of the test insects, reflecting the complete control ability of the pesticide on pests, providing a reference for the recommended concentration in the field (such as when control is required to achieve LC 90 The above ensures the control effect).

[0076] Test condition control

[0077] Environmental conditions (temperature 25±1℃, light / darkness=16h / 8h): simulate the suitable environment for citrus growth to avoid temperature / light fluctuation affecting the activity of test insects or the stability of pesticides;

[0078] Investigation time (48h after application): taking into account the action speed of the two pesticides (emamectin benzoate fast-acting + lufenuron slow-acting), 48h can fully reflect the comprehensive virulence of the compound pesticide;

[0079] Death judgment standard (body color brown and shriveled): citrus rust mites are light yellow, and turn brown and shriveled after death due to dehydration, this standard is intuitive and repeatable, reducing judgment errors.

[0080] Detailed work flow

[0081] Stage 1: Preparation of pesticides

[0082] Preparation of mother liquor:

[0083] Take 95% emamectin benzoate 0.1053 g, 97% chlorbenzuron 0.1031 g, respectively, dissolve with acetone and constant volume to 100 mL, get 1000 mg / L emamectin benzoate and 1000 mg / L chlorbenzuron mother liquor;

[0084] According to the mass ratio of active ingredients 2:1, 1:1, 1:2, 1:3, 1:4, take the corresponding volume of two kinds of mother liquor respectively, dilute with acetone to prepare a compound mother liquor.

[0085] Concentration gradient dilution:

[0086] Dilute the compound mother liquor with acetone to 2.4, 1.2, 0.6, 0.3, 0.15 mg / L, 5 concentrations, and set 4 repeats for each concentration;

[0087] Take pure acetone as a blank control.

[0088] Stage 2: Test insect preparation

[0089] Collect fruits damaged by red spider mites from citrus orchards, peel and take the fruit peel with insects;

[0090] Select healthy test insects under a stereomicroscope: retain light yellow, uniform size adult mites, and remove dead insects and residues;

[0091] Place 1 piece of fruit peel with 20 test insects in each culture dish (ensure consistent number of test insects), and place wet sponge and filter paper at the bottom of the culture dish (to maintain humidity).

[0092] Stage 3: Pesticide spraying

[0093] Adjust the Potter spray tower: stabilize the spray pressure at 1.47×10 5 Pa, wash the spray head with acetone twice and distilled water twice (to avoid residual interference);

[0094] Place the culture dish containing test insects at the bottom of the spray tower, and spray 1 mL of compound pesticide (or control acetone) of corresponding concentration per dish;

[0095] After the liquid settles for 1 min, transfer the culture dish to a constant temperature incubator (temperature 25±1℃, light / dark=16h / 8h).

[0096] Stage 4: Culture and investigation

[0097] After 48h of culture, take out the culture dish and observe the test insect state under a stereomicroscope;

[0098] Record the number of dead insects: judge death according to the standard of "body color turning brown and shriveling", and count the number of dead insects and total number of insects in each repeat.

[0099] Stage 5: Data calculation and analysis

[0100] Basic data calculation:

[0101] Calculate the mortality of each concentration according to the formula P1=(number of dead insects K / total number of insects N) x 100%;

[0102] If the control mortality is between 5%-20%, calculate the corrected mortality P2=(treatment mortality P t / (1-P0) x 100%.

[0103] Toxicity regression analysis:

[0104] Take the logarithm value of the concentration of the pesticide (mg / L) as x and the probability value of the corrected mortality as y, use DPS software to fit the toxicity regression equation Y=a+bx, and obtain the correlation coefficient r;

[0105] Calculate LC 50 (95% confidence limit) and LC 90 (95% confidence limit)

[0106] For example, the toxicity regression equation: the regression equation of 1:2 ratio is Y=5.7412+1.3220x (r=0.99), indicating that the concentration and mortality are significantly correlated.

[0107] Co-toxicity coefficient calculation:

[0108] Calculate the single-agent toxicity index TI(A), TI(B), the theoretical toxicity index TTI and the actual toxicity index ATI of the mixed agent according to the formula;

[0109] Calculate the co-toxicity coefficient CTC=(ATI / TTI) x 100% to determine the synergistic effect (CTC≥120 is synergistic).

[0110] Take emamectin benzoate as the standard pesticide, the TTI of 1:2 ratio is (0.22 / 0.22 x 100) x 1 / 3 + (0.22 / 0.94 x 100) x 2 / 3 ≈ 58.76; the ATI is (0.22 / 0.28) x 100 ≈ 78.57; the CTC is 78.57 / 58.76 x 100 ≈ 160.56, which is determined as synergistic effect.

[0111] Stage 6: result verification

[0112] When the CTC of the 5 ratios is all ≥120, and the CTC of 1:2 ratio is the highest (160.56), it is confirmed that the complex insecticide has significant synergistic effect on citrus rust mites, and can be used as the preferred scheme.

[0113] The specific experimental data is shown in Table 1 and Table 2

[0114] Table 1 Toxicity of emamectin benzoate, lufenuron and different ratios to citrus red mite

[0115]

[0116]

[0117] Table 2 Toxicity of emamectin benzoate and lufenuron different ratios to citrus red mite determination of raw data table

[0118]

[0119]

[0120] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary and that certain changes and modifications can be made thereto without departing from the principles and spirit of the application. The scope of the present application is therefore defined by the appended claims and their equivalents.

Claims

1. A combined insecticide of emamectin benzoate and lufenuron, characterized in that, The application relates to a complex insecticide for preventing and treating citrus red mites, which comprises active ingredients of emamectin benzoate and lufenuron, and synergistic effect is evaluated by using a co-toxicity coefficient (CTC), and the synergistic effect is determined when the CTC is greater than or equal to 120.

2. A mixture of emamectin benzoate and lufenuron according to claim 1, characterized in that, The mass ratio of the active ingredients of the emamectin benzoate and the lufenuron is 2:1, 1:1, 1:2, 1:3 or 1:

4.

3. The combined insecticide of emamectin benzoate and lufenuron according to claim 1, characterized in that, When the mass ratio of the active ingredients is 1:2, the co-toxicity coefficient of the emamectin benzoate and the lufenuron to the citrus red mites is 160.

56.

4. The combined insecticide of emamectin benzoate and lufenuron according to claim 1, characterized in that, The emamectin benzoate is a pure drug with a purity greater than or equal to 95%, the lufenuron is a pure drug with a purity greater than or equal to 97%, and a mother liquor is prepared by dissolving the lufenuron in acetone.

5. The combined insecticide of Emamectin benzoate and lufenuron as claimed in claim 1, wherein, The concentration gradient of the complex insecticide in the test was 2.4, 1.2, 0.6, 0.3, 0.15 mg / L, and the Potter spray tower was used to spray 1 mL of liquid with a 1.47 x 10 5 Pa pressure.

6. The combined insecticide of Emamectin Benzoate and Lufenuron as claimed in claim 1, wherein, The toxicity of the complex insecticide is evaluated by using mortality and corrected mortality, and the calculation formula is as follows: Mortality P1=(number of dead insects K / total number of insects N) * 100%; Corrected mortality P2 = (treated mortality P t - control mortality P0) / (1 - P0) x 100%.

7. The combined insecticide of Emamectin benzoate and lufenuron as claimed in claim 1, wherein, The regression equation of the toxicity of the complex insecticide is Y=a+bx, wherein the independent variable x is the logarithmic value of the concentration of the pesticide, the dependent variable y is the probability value of the corrected mortality, and the correlation coefficient r is greater than or equal to 0.

99.

8. The combined insecticide of Emamectin benzoate and lufenuron as claimed in claim 1, wherein, The co-toxicity coefficient (CTC) is calculated by the following formula: Single dose virulence index TI(A) = (standard agent LC 50 / agent ALC 50 ) x 100%; Single dose toxicity index TI (B) = (standard agent LC 50 / agent B LC 50 ) x 100%; Theoretical toxicity index TTI of the mixture=TI(A) * A proportion+TI(B) * B proportion; Actual Toxicity Index of mixture, ATI = (LC 50 of standard / LC 50 of mixture) x 100%; CTC=(ATI / TTI) * 100%.

9. The combined insecticide of Emamectin benzoate and lufenuron as claimed in claim 1, wherein, The complex insecticide has LC 50 values of 0.23-0.45 mg / L, LC 90 values of 2.42-3.40 mg / L.

10. The combined insecticide of Emamectin Benzoate and Lufenuron as claimed in claim 1, wherein, The test conditions of the complex insecticide are that the temperature is (25+ / -1) DEG C, the light / darkness is 16h / 8h, the mortality investigation time of the test insects is 48h after the pesticide is applied, and the judgment standard is that the body color is brown and dry, and the insects are determined to be dead.

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