A biological pesticide for controlling macadamia thrips

Abstract

The invention belongs to the technical field of pesticides, and specifically belongs to a biological pesticide for preventing and controlling macadamia thrips. A biological pesticide for preventing and controlling macadamia thrips, wherein the effective component is a binary compound of methyl salicylate and ivermectin, temycin or farnesol. When the methyl salicylate of the invention is compounded with ivermectin, temycin or farnesol in a certain mass ratio, a synergistic effect is shown in preventing and controlling macadamia thrips such as tea yellow thrips within a certain mass ratio range, and compared with a single effective component, the control effect on macadamia thrips can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and in particular to a biological pesticide for preventing and controlling macadamia nut thrips. Background Art

[0002] Thrips are one of the main pests of macadamia nuts. Thrips gather as adults or nymphs to damage the inflorescence, young fruits, tender shoots and leaves of macadamia nuts, causing low fruit set rate, fruit shedding or brown spots on the fruit skin, narrow and long tender leaves that become smaller and curled, and stunted or poor growth of tender shoots. The main thrips that damage macadamia nuts in my country include Selenothrips rubirocintus Giard, Gynaikothrips sp., Thrips coloratus Schmutz and Scirtithrips doraslis Hood. Among them, Scirtithrips doraslis Hood has the greatest tendency to attack the inflorescence of macadamia nuts, with hundreds of them often on one inflorescence; the second is tender shoots and leaves, with several to dozens of them on one leaf; the third is young fruits, with several to dozens of them on each young fruit.

[0003] Chemical pesticides are the main means of controlling agricultural pests and diseases. Thrips on macadamia nuts can be controlled by spraying pesticides. With the long-term use of existing pesticides, macadamia thrips have developed varying degrees of resistance to existing chemical pesticides. In order to achieve better control effects, fruit farmers usually increase the dosage and frequency of pesticide application, which increases the cost of control and also increases the amount of pesticide residues on macadamia nuts.

[0004] Methyl salicylate, CAS: 119-36-8, is the main component of wintergreen oil, also known as methyl salicylate, methyl 2-hydroxybenzoate. Application No. CN201310496646.9 discloses a plant-derived fumigant insecticide containing methyl salicylate and trans-cinnamaldehyde, and specifically discloses that the combination of methyl salicylate and trans-cinnamaldehyde has a synergistic effect on the prevention and control of mosquitoes, flies and other sanitary pests. In addition, Application No. CN201810650697.5 discloses a thrips-killing plant essential oil composition, preparation and application thereof, and specifically discloses that when wintergreen oil (the main component is methyl salicylate, with a content of more than 99%) and oregano oil are used in combination, thrips can be prevented and controlled, and have a significant synergistic effect, are not easy to develop drug resistance, and are a non-polluting plant-derived thrips control agent that is safe for humans and animals and does not pollute the environment.

[0005] Compounding different pesticide ingredients is a common method for developing new agents. In most cases, the compounding of pesticides is additive, and there are few compounds that truly have synergistic effects. The inventors found through a large number of indoor experiments that compounding methyl salicylate with ivermectin, avermectin or farnesol showed a synergistic effect on the control of macadamia nut thrips (such as tea yellow thrips).

[0006] At present, there are no reports on the combination of methyl salicylate with ivermectin, avermectin or farnesol.

[0007] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] The object of the present invention is to provide a biological pesticide for controlling macadamia thrips, so as to solve the problem that macadamia thrips have developed different degrees of resistance to existing chemical agents due to long-term use of existing agents. In order to achieve better control effects, fruit farmers usually increase the application dosage and frequency of pesticides, which increases the control cost and also increases the pesticide residue in macadamia nuts.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A biological pesticide for controlling macadamia nut thrips, wherein the active ingredient is a binary compound of methyl salicylate and ivermectin, avermectin or farnesol.

[0011] Preferably, the mass ratio of methyl salicylate to ivermectin is 1-10:5-1.

[0012] Preferably, the mass ratio of methyl salicylate to tianweimectin is 1-30:30-1.

[0013] Preferably, the mass ratio of methyl salicylate to farnesol is 1-9:7-1.

[0014] The present invention also provides use of the biological pesticide for controlling macadamia nut thrips in controlling red-banded reticulated thrips, fig thrips, colored thrips and tea-yellow thrips.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) When the methyl salicylate of the present invention is compounded with ivermectin, avermectin or farnesol in a certain mass ratio, it shows a synergistic effect on controlling macadamia nut thrips such as tea yellow thrips within a certain mass ratio range. Compared with a single active ingredient, the control effect on macadamia nut thrips can be improved, and the generation and development of pest resistance can be delayed.

[0017] (2) The methyl salicylate, ivermectin, tebuconazole and farnesol of the present invention are plant-derived biological pesticide ingredients, which are environmentally friendly and can reduce environmental pressure. DETAILED DESCRIPTION

[0018] The present invention may be better understood according to the following embodiments. The contents described in the embodiments are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0019] Example :Indoor biological activity test of methyl salicylate compound

[0020] 1. Test subjects: Scirtithrips doraslis Hood, collected from macadamia plantations, were reared for several generations in the laboratory on fresh and clean young macadamia leaves. Healthy first-instar nymphs of uniform size were selected as test subjects.

[0021] 2. Test reagents

[0022] 98% methyl salicylate, 94% ivermectin, 98% temycin (the mass ratio of temycin A to temycin B is 8:2), 99% farnesol (CAS: 4602-84-0);

[0023] The test drug was first dissolved in dimethyl sulfoxide to prepare a single-dose stock solution, and then diluted with a 0.1% Tween-80 aqueous solution to set up multiple groups of ratios. Each single dose and each group of mixed ratios were set to 5 gradient mass concentrations according to the equal ratio method for use.

[0024] 3. Test method: (Refer to "NY / T 1154.6-2006 Pesticide Indoor Bioassay Test Guidelines Insecticides Part 6: Insecticide Activity Test Insect Immersion Method");

[0025] The test insects were immersed in the liquid for 10 seconds, and the excess liquid was absorbed with filter paper and then transferred to normal conditions for feeding. Each treatment was repeated 4 times, with 20 insects immersed in each repetition, and the treatment containing only dimethyl sulfoxide and 0.1% Tween-80 was set as a blank control. The death of the test insects was observed 24 hours after the treatment, and the total number of insects and the number of dead insects in each treatment were recorded respectively, and the corrected mortality rate of each treatment was calculated based on this.

[0026]

[0027] In the above formula: P--mortality rate, unit is %; K--number of dead insects; N--total number of insects treated.

[0028]

[0029] In the above formula: P1--corrected mortality rate, unit is %; P t --Treatment mortality rate, in %; P0--blank control mortality rate, in %.

[0030] 4. Data analysis: DPS software was used to perform regression analysis on the logarithmic values ​​of the concentration of each treatment agent and the corrected mortality probability value of each treatment, and the LC of each treatment agent was calculated. 50 , and the co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method.

[0031]

[0032] In the above formula: ATI--the toxicity index of the mixture; S--the LC of the standard agent 50 , the unit is mg / L; M--LC of the mixture 50 , unit is mg / L.

[0033] TTI=TI A ×P A +TI B ×P B

[0034] In the above formula: TTI-theoretical toxicity index of the mixture; TI A --Toxicity index of A agent; P A --The percentage of agent A in the mixture, in percentage (%); TI B --Toxicity index of agent B; P B --The percentage of agent B in the mixture, in percentage (%).

[0035]

[0036] In the above formula: CTC--co-toxicity coefficient; ATI--actual toxicity index of the mixture; TTI--theoretical toxicity index of the mixture.

[0037] 5. Efficacy evaluation

[0038] The synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC), CTC≤80 was antagonistic, 80<CTC<120 was additive, and CTC≥120 was synergistic. The results are shown in Table 1-3.

[0039] Table 1 The results of toxicity test of methyl salicylate and ivermectin against Thrips lutea

[0040] Drug name and ratio <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC Methyl salicylate 8.9487 100.0000 -- -- Ivermectin 4.2574 210.1917 -- -- Methyl salicylate 1: Ivermectin 5 2.5093 356.6214 191.8264 185.9084 Methyl salicylate 1: Ivermectin 3 3.2626 274.2812 182.6437 150.1728 Methyl salicylate 1: Ivermectin 1 4.0977 218.3835 155.0958 140.8055 Methyl salicylate 3: Ivermectin 1 5.3231 168.1107 127.5479 131.8020 Methyl salicylate 5: Ivermectin 1 2.6501 337.6741 118.3653 285.2813 Methyl salicylate 10: Ivermectin 1 1.4834 603.2560 110.0174 548.3277

[0041] As can be seen from Table 1, within the mass ratio of 1-10:5-1, the co-toxicity coefficient of methyl salicylate and ivermectin against Thrips oleraceus was greater than 120, showing a synergistic effect.

[0042] Table 2 The results of toxicity test of methyl salicylate and tianweimectin against tea yellow thrips

[0043]

[0044]

[0045] As can be seen from Table 2, within the mass ratio of 1-30:30-1, the co-toxicity coefficient of methyl salicylate and tianweimectin to tea yellow thrips was greater than 120, showing a synergistic effect.

[0046] Table 3 The results of toxicity test of methyl salicylate and farnesol against Thrips oleifera

[0047] Drug name and ratio <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC Methyl salicylate 8.9487 100.0000 -- -- Farnesol 134.2961 6.6634 -- -- Methyl salicylate 1: Farnesol 7 37.0048 24.1825 18.3305 131.9253 Methyl salicylate 1: Farnesol 3 24.0763 37.1681 29.9976 123.9037 Methyl salicylate 1: Farnesol 1 13.8973 64.3916 53.3317 120.7380 Methyl salicylate 3: Farnesol 1 9.3394 95.8166 76.6659 124.9796 Methyl salicylate 7: Farnesol 1 7.9198 112.9915 88.3329 127.9155 Methyl salicylate 9: Farnesol 1 5.0425 177.4655 90.6663 195.7348

[0048] As can be seen from Table 3, within the mass ratio of 1-9:7-1, the co-toxicity coefficient of methyl salicylate and farnesol to Thrips oleraceus was greater than 120, showing a synergistic effect.

[0049] In summary, when the methyl salicylate of the present invention is compounded with ivermectin, avermectin or farnesol in a certain mass ratio, it shows a synergistic effect on controlling macadamia thrips such as tea yellow thrips within a certain mass ratio range. Compared with a single active ingredient, the control effect on macadamia thrips can be improved, and the generation and development of pest resistance can be delayed.

[0050] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A biological pesticide for controlling macadamia thrips, characterized in that: The effective component is prepared by binary compounding of methyl salicylate and farnesol, and the mass ratio of the methyl salicylate to farnesol is 1-9:7-1.

Images