JPH0558602B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is directed to the control and extermination of agricultural, forestry and livestock pests, sanitary pests, etc. (hereinafter simply referred to as "pests") (hereinafter both may be collectively referred to as "control").
Regarding. (Prior art) It is no exaggeration to say that after World War II, humanity secured food through the development and development of synthetic pesticides, escaped many infectious diseases, and built the prosperity we have today. In particular, the development of insecticides, fungicides, herbicides, acaricides, nematicides, and the like has been remarkable, and many of them are now in practical use. On the other hand, insect parasitic nematodes are used for pest control even when applied alone.
In Japan, it has been rapidly developed in the past few years and has been successful in exterminating difficult-to-control pests. but,
There are still many problems to be developed, and stable effects cannot be expected when applied alone. (Problems to be Solved by the Invention) However, it is a well-known fact that the heavy use of agricultural chemicals and sanitary insecticides destroys ecosystems and causes environmental pollution. Synthetic insecticides will continue to be needed, but their development currently requires huge amounts of money. Moreover, even when it reaches the stage of general use,
In some cases, pests develop resistance after a few years, forcing the application rate to be increased or making it impossible to use it at all. This in itself not only worsens the environment, but also causes great losses to related companies. On the other hand, insect parasitic nematodes are extremely resistant to insecticides commonly used against agricultural pests.
Mixed application with synthetic pesticides has previously been theoretically possible, but no examples have actually been investigated and no technology has been established. (Means for Solving the Problems) As a result of many years of research, the present inventor has succeeded in solving the above-mentioned conventional problems through the synergistic effect produced by various synthetic pesticides and useful nematodes, and has developed the present invention. It is completed. That is, an object of the present invention is to achieve a high pest control rate using a small amount of synthetic pesticide without imparting resistance to pests. Another purpose is to easily and easily carry out comprehensive control of pests and harmful nematodes. The ultimate purpose of the present invention is to increase the yield of agricultural and forestry crops, livestock products, etc., to prevent epidemics of livestock and livestock, and to conserve the environment. The above method is characterized in that a synthetic concentration having a concentration range capable of activating the movement of useful nematodes is applied to a pest habitat in combination with useful nematodes in the above concentration range. This is achieved through pest control methods. The pests to which the method of the present invention can be effectively applied include agricultural pests, soil pests/nematodes, sanitary pests, livestock pests,
It is at least one species selected from the group consisting of forestry pests. When the synthetic agricultural chemical is at least one selected from the group consisting of insecticides, fungicides, herbicides, and acaricides, the combined application is preferably carried out in combination with useful nematodes. Also, when synthetic pesticides are soil fumigants,
The above-mentioned combined application is preferably carried out by alternating application with useful nematodes after soil fumigation and degassing. The useful nematode suitably applied to the method of the present invention is at least one species selected from the group consisting of insect-parasitic nematodes and fungivorous nematodes excluding plant-parasitic nematodes. Hereinafter, the structure of the method of the present invention will be explained in more detail. Examples of useful nematodes suitable for use in the method of the present invention include the following insect-parasitic nematodes and fungivorous nematodes. Insect-parasitic nematodes: Steinernematidae Heterorhabditidae Bacterivorous nematodes: Bacterivorous nematodes of the order Aphelenchida, excluding plant parasitics. Aphelenchus avenii (Aphelenchus)
avenae). Aphelenchoides spp. For insect-parasitic nematodes, use 3rd stage larvae in the infective state, and for fungivorous nematodes, use 4th stage larvae or young adults.
These nematodes were mass-produced in artificial media. The agricultural chemicals may be insecticides, fungicides, herbicides, acaricides, etc., and are not particularly limited, as long as they have a certain concentration range that can activate the movement of nematodes. It may be selected depending on the purpose of use. Cannot be mixed with fumigants. To create a synergistic effect, for example, an insect parasitic nematode and an insecticide may be mixed. For comprehensive control of soil pests and harmful nematodes, for example, the insect parasitic nematode Steinernema fuerteii
feltiae) DD-136 series and Vydate
(Product name of plant nematode control agent manufactured by DuPont in the United States,
In the case of a combination with Oxamyl 1% granules (component name), the usual application concentration of Vidate is 35 kg/10a and 250,000 to 500,000 to 500,000 nematodes/m ² are applied together. For above-ground pests, for example, approximately 5,000 nematodes/ml are mixed into a 2,000x solution of organophosphorus insecticide DDVP50% emulsion, and a fatty acid-paraffin mixture Avion-C (Tokyo, Avion Chemical Research Institute) is used as a spreading agent. Use 1000 times the amount of If the synthetic pesticide is a fumigation agent, apply harmful insect pests to the fumigated soil. In other words, the desired effect can be obtained by alternately performing fumigation and application of useful nematodes. (Effects) (a) Simultaneous application of mixtures: The reason why the mortality rate of pests increases when nematodes and synthetic pesticides are mixed is because the insects lose their resistance to the drug due to the invasion of nematodes, or because the drugs provide protection against nematodes. It is better to think that this is not due to a decrease in power, but simply because the nematodes are stimulated by the pesticide, become excited, move more actively, and invade the insect body more often. Figure 1a of the attached drawings is an enlarged photomicrograph of infected larvae of the nematode Steinernema fuerteiai (DD-136 series) thrown into water, and Figure 1b is an enlarged view of the nematodes in a 30 ppm solution of oxamyl. Soak 48
It is also an enlarged view after a period of time. As is clear from the comparison between the two figures, the nematodes are in a straight line and stop moving in water, but when exposed to oxamyl
In a 30ppm solution, it is still actively moving after 48 hours. In the case of oxamyl, it is most active at 30 to 70 ppm, and if the concentration is higher than this, the nematodes become stationary and the insecticidal effect decreases. In more detail, such synthetic pesticides enhance the nictaing behavior (a state in which the nematodes stand up and sway on their tails or stand still and erect) of the infected larvae of useful nematodes treated under the conditions described below. [See Figures 1a and 1b] is assayed by observation under a microscope. That is, in a Petri dish with a diameter of 6 cm, put 4 ml of a suspension of the pesticide to be tested (below the concentration actually used) and useful nematodes, such as Steinernema infective larvae (approximately 20,000 individuals), and add bark compost on top. (diameter 1
(passed through a mm sieve and dried at 170℃ for 2 hours)
Layer 2g. After leaving it in a dark place at 25℃ for 1 day,
Count the nictating nematodes under a 60x binocular stereomicroscope. The number of nematodes to be nictated in the control area (water and nematodes) is 100, and the number of nematodes to be nictated should be 100 or more. however,
Counting must continue for at least 4 days. This also applies when mixing with other pesticides, but if the concentration of the pesticide is high, the nematodes become quiescent and the effectiveness of the mixed application is reduced. Therefore, in the case of mixed application, it is important to set the concentration of the pesticide to an appropriate value that will activate the movement of useful pests. On the other hand, if a large number of nematodes are inoculated, the effect will be greater, so it cannot be said to be a synergistic effect. In practical terms, it is important that the effects appear when they are mixed, while the effect is not apparent when each is applied alone. This is because in actual application,
This is because both are extremely diluted, especially in soil. (b) Application of nematodes to fumigated soil: The more the soil is disinfected, the easier it is for invasive pests to enter and the greater the damage. Populations of surviving harmful nematodes (or those that have invaded) recover rapidly. Soil becomes physically and biologically exhausted, loses its productivity, and loses its purifying function, which is considered to be the most important. Beneficial nematodes applied to soil also survive longer in soils with reduced biological buffering capacity and effectively intercept invasive disease nematodes. Furthermore, if a large amount of useful nematodes are introduced before the harmful nematodes recover, the recovery of the harmful nematodes will be suppressed. This mechanism is not yet well understood, but the phenomenon has already been demonstrated. In specialty producing areas, soil fumigation is carried out after each crop, and in melon and watermelon producing areas, soil fumigation three times a year is not uncommon. The alternating application of the present invention can be expected to reduce the number of applications to once a year, which in itself will reduce the amount of pesticides, which will greatly benefit both farmers and consumers, and will lead to healthy agriculture. Become. (Example) The present invention will be described below with reference to Examples. Example 1 (Laboratory test of mixed application) (Method) A Petri dish with a diameter of 9 cm was lined with filter paper, and oxamyl [2-dimethyl-amino-1-(methylthio)glyogyzal-0-methyl-carbomoyl-monoxime] 10, 62.5, 100, 250,
Add 50, 100, 200 infected larvae of Steinernema fuerteii DD-136 to 1 ml of 1000 ppm aqueous solution.
Includes 400, 800, and 1000 animals (so the combination is 6×
6 = 36 ways) 6th instar larva of Kaburaya moth (fasted at the 6th instar, fed at the start of the light period, 0 at the end of the instar)
25℃ without food).
The investigation was conducted for 8 days. Nematodes were applied first and oxamyl was applied two days later. They also conducted an experiment in which they first treated insects with oxamyl and then treated 1,000 nematodes two days later. (Results) The LD ₅₀ of Steinernema fuerteiai for Kabraya moth final instar larvae is 4 at 25℃.
There were 80 animals in one day. (Y=1.54396+1.98026X,
Y is the probit value of mortality rate, X is the logarithm of the number of nematodes).
Even when treated with oxamyl alone at 1000 ppm for 4 days, the mortality rate of cabrayaga moths was 0. On the other hand, Steinernema Fuerteiai contains 1000ppm of oxamyl.
(24-hour treatment) causes the body to become stagnant, but when returned to water, it is 100% resuscitated. FIG. 2 is a graph showing the mortality rate over time of the Agrotis segetum when various concentrations of oxamyl and DD-136 (1000 animals) were mixedly applied to the Agrotis segetum. In the same figure, when the concentration of oxamyl is high, the nematodes become stationary, and the effect of the mixture does not appear. Even if the concentration of the drug is lowered, if a large number of nematodes are inoculated, the effect will only be on the nematodes, so it is necessary to confirm the effect by reducing the number of nematodes to the extent that the nematodes alone will not be effective. Figure 3 shows each concentration of oxamyl and DD-136 (200
It is a graph showing the mortality rate of Kaburaya moth larvae over time in the case of simultaneous application of the head). In this case, the nematode
For 200 cows, a mixture of 62.5 ppm of oxamyl became more effective than each application alone. Next, Figure 4 shows the case where the number of nematodes (DD-136) was further reduced to 50 at the same time. An insect killing rate of over 75% was obtained when mixed with With only 50 nematodes, only about a 30% killing rate can be achieved. Of course, oxamyl alone has an insecticidal rate of 0% at this concentration. Figure 5 shows that Kabraya moth larvae were pretreated with oxamyl at various concentrations, and two days later, 1000 DD-136 larvae were
It is a graph showing the mortality rate over time when the head is inoculated. In an experiment in which oxamyl was treated and 1,000 nematodes were treated two days later, the insecticidal rate was lower than when the mixture was applied at the same time. On the other hand, an experiment in which nematodes were applied first and oxamyl was applied two days later was no different from application of nematodes alone. Example 2 (Mixed application pot test) (Method) Sterilized soil in a 1:20,000 Wagner pot
10 liters of Vidate Granules (Oxamil 1
%), the effective concentration is 50, 100, 200, 350,
Add 0.25, 0.5, 1.0, 1.75, 2.5g to take 500g,
After mixing the soil, 20,000 Steinernema fuerteiai were applied per pot (250,000/m ² ).
Fifty Kaburaya moth larvae were placed, the soil moisture was maintained at 30%, the temperature was kept at 23-28°C, and mortality was investigated 6 days after feeding with artificial feed. The experiments were conducted twice for each instar of Kaburaya moth larvae using 5-day, 11-day-old, and 14-day-old after hatching. (Results) Table 1 shows the results.

[Table] In the Bidate 2.5g (50Kg/10a) plot, the Kaburaya moth larvae did not die at all. In the nematode-only plot, the killing rate was high at 78.5% when the Kabraya moth was a young larva, but the mortality rate was less than 30% when it was 11 and 14 days old. Bidate 1.75g (35Kg/10a) for mixed application
The insect killing rate was the highest at 2.5g (50Kg/10a), but it was even lower at 2.5g (50Kg/10a). In this way, in the pot test, a synergistic effect was observed in the mixture of nematodes and pesticides. It is noted that 2.5g (3.5Kg/10a) of Vidate is a common soil application rate for this agent and is within the practical application range. Example 3 (Field test of mixed application) Soil application of nematodes and bidate (Method) 8 plots of 2m x 3m were set up, divided into 4 plots each, and on February 28th, Telone [manufactured by Sumitomo Chemical Co., Ltd.] was applied. , nematocidal product name, 1,3-dichloropropene 92%] 20/
Treated with 10a. In general, soil-applied insect parasitic nematodes have a high survival rate in fumigated or steam-sterilized soil, and invasive pests also cause great damage in such soils, so plots with and without Teron treatment were established. On May 4th, two plots of Vidate granules (30 kg/10 a) were treated with teron and untreated. Diameter 5.5cm x May 8th
40 PVC pipes with a length of 30cm in one plot,
Insert the tube to a depth of 20cm and place one green bean seedling in the tube.
Planted Steinernema Fuerteii (All
One day after spraying 10,000 larvae/tube on the soil surface, one mature larva of Kabra Yaga was added to the tube, and 4 days later, the percentage of dead plants of green beans was investigated. (Results) Table 2 shows the results.

[Table] Ma fuerteii insect parasitic nematode 45 95 55 90
none

Claims (1)

[Scope of Claims] 1. A synthetic concentrate having a concentration range capable of activating the movement of useful nematodes is applied to a pest habitat in combination with useful nematodes in the above concentration range. Pest control methods. 2. The pests are agricultural pests, soil pests, nematodes,
Claim 1 is at least one species selected from the group consisting of sanitary pests, livestock pests, and forestry pests.
Pest control methods described in section. 3. The pest control method according to claim 1, wherein the synthetic pesticide is at least one selected from the group consisting of insecticides, fungicides, herbicides, and acaricides, and the combined application is mixed application. . 4. The pest control method according to claim 1, wherein the synthetic agricultural chemical is a soil fumigation agent, and the combined application is alternating application of the fumigation and useful nematodes. 5. Claims 1, 2, and 3, wherein the useful nematode is at least one species selected from the group consisting of insect-parasitic nematodes and fungivorous nematodes excluding plant-parasitic nematodes.
or the pest control method described in Section 4.