CN102792968B - Insecticide for controlling potato beetles - Google Patents

Abstract

The invention discloses an insecticide for controlling potato beetles. The composition and weight content of the insecticide are: 24-90% of cyfluthrin and 10-76% of chlorpyrifos. The invention also simultaneously discloses the cream type insecticide prepared by using the above insecticide for preventing and controlling potato beetles, and each L of the cream type insecticide contains 2-60 g of the insecticide for controlling potato beetles. The invention also discloses the emulsion-in-water insecticide prepared by using the insecticide for preventing and controlling potato beetles at the same time, and each L of the emulsion-in-water insecticide contains 2-60 g of the insecticide for controlling potato beetles. The insecticide of the present invention has the characteristics of ideal insecticidal effect, long duration, low cost and the like.

Description

Insecticides against potato beetles

technical field

The invention belongs to the technical field of compound pesticides, in particular to an insecticide for controlling potato beetles.

Background technique

Potato beetle (Leptinotarsa decemlineata Say) belongs to Coleoptera, Chrysocaridae, also known as potato leaf beetle or Colorado potato beetle. Potato beetles damage potatoes, tomatoes, eggplants and other solanaceous vegetables, often reducing the yield of these vegetables by about 30% to 50%, or 90% in serious cases, and also spread potato brown spot and ring rot.

Since the potato beetle was first discovered in Huocheng County, Ili Prefecture, Xinjiang in May 1993, the distribution of the potato beetle has expanded to an area of about 260 000 ^km2 in 8 prefectures and 35 counties and cities in the Junggar Basin north of the Tianshan Mountains by 2009. And the potato-growing areas of the regiments belonging to the above-mentioned regional corps. At present, it is distributed in most parts of northern Xinjiang in my country, and the area of the epidemic area has expanded hundreds of times. Moreover, in recent years, the potato beetle has shown a trend of accelerating the spread and aggravating the damage.

Potato beetles can easily become resistant to chemical agents. So far, the insect has produced varying degrees of resistance to organochlorine, organophosphate, carbamate and pyrethroid pesticides abroad. Over the years, the effectiveness of chemical control against potato beetles in northern Xinjiang has also been declining. In China, organophosphorus, carbamate, and pyrethroid insecticides are mostly used to control this insect, while abroad, because this insect has developed high resistance, insecticides with novel action mechanisms are often used in the control.

Cyfluthrin is a synthetic pyrethroid insecticide containing fluorine and low toxicity. It has high insecticidal activity and is a nerve agent. It has contact and stomach poisoning effects and has effective penetration into plant tissues. Its drug effect is rapid, the residual effect period is long, and it is safe for crops. It has a wide insecticidal spectrum and is effective against various pests such as Lepidoptera, Hemiptera, Coleoptera and Diptera. The main mechanism of potato beetle resistance to pyrethroid insecticides is the enhancement of oxidative metabolism.

Chlorpyrifos (chlorpyrifos) is a moderately toxic organophosphorus insecticide and acaricide with a wide insecticidal spectrum and has contact killing, stomach poisoning and fumigation effects. Good mixing compatibility, can be mixed with a variety of insecticides and the synergistic effect is obvious. Carboxylesterase overproduction is a mechanism of resistance to organophosphate insecticides in potato beetles.

At present, most of the pesticides used to control potato beetles are controlled by a single agent, and the reasonable mixture of pesticides is expected to produce synergistic effects and delay the emergence of drug resistance.

Contents of the invention

Aiming at the problems existing in the prior art, the problem to be solved by the present invention is to provide an insecticide for preventing and controlling potato beetles with ideal insecticidal effect, long-lasting effect and low cost.

In order to solve the above technical problems, the present invention provides an insecticide for controlling potato beetles. The composition and weight content of the insecticide are: 24-90% of cyfluthrin and 10-76% of chlorpyrifos.

The present invention also simultaneously provides an emulsifiable cream insecticide prepared by using the above insecticide for controlling potato beetles, and each L of the emulsifiable oil type insecticide contains 2-60 g of the insecticide for controlling potato beetles.

The invention also provides the water-emulsion insecticide made by using the insecticide for controlling the potato beetle, and each L of the water-emulsion insecticide contains 2-60 g of the insecticide for controlling the potato beetle.

The present invention is realized in the following way: according to the respective characteristics of cyfluthrin and chlorpyrifos, rational compounding is carried out, and a combination ratio with obvious synergistic effects is screened out through a series of indoor bioassays and field tests.

The insecticide for preventing and controlling potato beetle of the present invention can be made into cream type insecticide according to existing conventional techniques, that is, adding organic solvent and emulsifier in the former drug (insecticide for preventing and controlling potato beetle), above-mentioned organic solvent and emulsifying The solvents are conventional varieties used when preparing pesticides. For example, the organic solvent can be xylene, and the emulsifier can be Nongru No. 600.

The insecticide for preventing and controlling potato beetle of the present invention can also be made into a water-emulsion type insecticide according to the existing conventional technology, that is, adding organic solvent, cosolvent, wetting agent, dispersing agent to the original drug (the insecticide for controlling potato beetle) agent, emulsifier and water, etc.; the above-mentioned organic solvents, co-solvents, wetting agents, diffusing agents, and emulsifiers are all conventional varieties used in the preparation of pesticides. For example, the organic solvent can be ethylene oxide-propylene oxide embedded Segment copolymer, cosolvent can choose glycol ether, wetting agent can choose pull-off powder, dispersant can choose alkylbenzene sulfonate, emulsifier can choose gum arabic.

In the present invention, unless otherwise stated, all percentages are percentages by weight.

When the insecticide for preventing and controlling potato beetles of the present invention is actually used in the field, the emulsifiable oil type insecticide or water emulsion type insecticide is diluted with water to an effective concentration (that is, the insecticide for controlling potato beetles) is 0.092 to 0.040 grams /L, the method of use is foliar spray; until the surface of the plant is completely wet and water droplets flow down. Therefore, the active ingredient used per mu is about 0.5 to 2 grams (this data is the amount of insecticide used to control potato beetles, that is, the effective amount in emulsifiable oil type insecticide or water emulsion type insecticide).

The insecticide for preventing and controlling potato beetles of the present invention has the best synergistic effect, the co-toxicity coefficient on potato beetle larvae reaches 297.2-423.3, the insecticidal effect is ideal, the quick-acting and long-lasting effects are good, the cost is low, and the cost is greatly reduced. production and use costs of pesticides.

In summary, according to the actual occurrence and control of potato beetles in my country, and considering the best synergistic effect and production cost of cyfluthrin and chlorpyrifos, the insecticide developed by the present invention has ideal insecticidal effect and long-lasting effect. Long and low cost.

Detailed ways

Specific implementation methods are given below through recipes, and the present invention is further described in detail in conjunction with test examples.

Formula 1: Cyfluthrin 56.68% + Chlorpyrifos 43.32%;

Formula 2: Cyfluthrin 66.24% + Chlorpyrifos 33.76%;

Formula 3: Cyfluthrin 75.33% + Chlorpyrifos 24.67%.

Test example 1:

The above three compound formulations (formula 1~formula 3), 5.7% cyfluthrin water emulsion (prior art) and 40% chlorpyrifos emulsifiable concentrate (prior art) used the 2nd instar potato beetle as the object, and carried out bioassays indoors. Using the leaf dipping method proposed by the International Resistance Action Committee (IRAC), on the basis of the preliminary test, the test agent was made into a certain concentration of the mother solution, and then diluted with water to 5 concentrations, and the water was set as the control group. Cut fresh potato leaves into 5cm-long leaf strips, soak them in each liquid to be tested for 10 seconds, take them out and dry them, put them in a petri dish previously lined with filter paper, and connect several potato leaf strips to each dish, and pick up 10 second-instar larvae. head. Each concentration was repeated 4 times. After covering the dish cover, raise them at a temperature of about 25°C, place them in an observation room for cultivation, and change the soaked leaves and filter paper from time to time, check the death of the test insects after 48 hours, calculate the death rate, and analyze it according to the probability value Calculate the toxicity regression formula, correlation coefficient (R) and lethal concentration (LC50) by using the method. The criteria for the death of larvae are: lightly touch the body of the test worm with the tip of a brush, and those who have no obvious spontaneous response are judged as dead. The details are shown in Table 1 and Table 2.

Table 1 The results of biological activity determination of each treatment on potato beetle

instruction manual:

The above treatment concentration (g/L) refers to the content of active ingredients. in particular:

In 5.7% cyfluthrin aqueous emulsion, it refers to the content of cyfluthrin;

In 40% chlorpyrifos EC, it refers to the content of chlorpyrifos;

In formula 1 to formula 3, it refers to the sum of the contents of cyfluthrin and chlorpyrifos.

The following are similar.

Table 2 Contact toxicity and synergistic effect of different ratios of cyfluthrin and chlorpyrifos on second instar larvae of potato beetle

Toxicity index (TI) of cyfluthrin = LC ₅₀ of chlorpyrifos / LC ₅₀ of cyfluthrin * 100,

Toxicity index (TI) of chlorpyrifos = LC ₅₀ of cyfluthrin / LC ₅₀ of chlorpyrifos * 100,

Actual toxicity index (ATI) of M = LC ₅₀ of cyfluthrin / LC ₅₀ of M * 100,

Theoretical Toxicity Index (TTI) of M = TI*P Chlorpyrifos for Chlorpyrifos + TI*P Cyfluthrin for Cyfluthrin,

M's co-toxicity coefficient (CTI) = M's ATI/M's TTI*100;

In the formula: M is the mixture of different proportions of cyfluthrin; P chlorpyrifos represents the proportion of chlorpyrifos in the mixture; P cyfluthrin represents the proportion of cyfluthrin in the mixture.

The measurement results showed that the co-toxicity coefficients of three different ratios of cyfluthrin and chlorpyrifos to the second instar larvae of potato beetle were all greater than 100, which had obvious synergistic effect, and the co-toxicity coefficient was the highest when the ratio of cyfluthrin and chlorpyrifos was 56.68:43.32. 423.3, both 66.24: 33.76, followed by 357.0.

Test example 2:

In the potato test field, the size of the test plants was selected to be the same. In order to ensure that each potato plant had second-instar larvae, the larvae of other instars of the potato beetle on the potato plants were removed. Four replicates were set up for each treatment, and there was a blank control group and a single-dose control group, and the method was foliar spraying; until the plant surface was completely wet and water droplets flowed down (that is, the spray volume after dilution was the same). After spraying, the number of dead and live insects were recorded two days later. The details are shown in Table 3.

Table 3 Field control effect of blank control group, single dose and different ratios of cyfluthrin and chlorpyrifos on second instar larvae of potato beetle

The results of field experiments showed that when cyfluthrin and chlorpyrifos were mixed in different proportions compared with the two single agents, even at a lower concentration than the single agent, the control effect on the second instar larvae of the potato beetle was still higher than that of either agent. single dose used. It can be seen that the compound of cyfluthrin and chlorpyrifos has a good control effect on potato beetle.

Comparative experiment 1,

The present invention also sets the following 6 kinds of formulas,

Formula 4: Cyfluthrin 92.17% + Chlorpyrifos 7.83%;

Formula 5: Cyfluthrin 83.96% + Chlorpyrifos 16.04%;

Formula 6: Cyfluthrin 46.59% + Chlorpyrifos 53.41%;

Formula 7: Cyfluthrin 35.93% + Chlorpyrifos 64.07%;

Formula 8: Cyfluthrin 24.65% + Chlorpyrifos 75.35%;

Formula 9: Cyfluthrin 12.69% + Chlorpyrifos 87.31%;

The above-mentioned 6 kinds of formulas are detected according to the mode of the above-mentioned test example 2, and the results are shown in the following table 4:

Table 4

Finally, it should also be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (3)

1. the purposes of insecticide in the control potato beetle, it is characterized in that the component and weight content of this insecticide are following any one: Cyfluthrin 66.24% and chlorpyrifos 33.76%; Cyfluthrin 56.68% and chlorpyrifos 43.32%. 2. the purposes of insecticide according to claim 1 in the control potato beetle is characterized in that: described insecticide is mixed with cream type insecticide when using, and in described every liter of cream type insecticide contains 2-60g of insecticide. 3. the purposes of insecticide according to claim 1 in the control potato beetle is characterized in that: when described insecticide is used, be mixed with water emulsion type insecticide, in every liter of water emulsion type insecticide Contains 2-60g of insecticide.