JP7123380B2 - Acaricidal composition - Google Patents

Description

NPMD NITE P-1104

The present invention relates to an acaricidal composition, acaricidal method and an acaricidal method.

Conventionally, various studies and proposals have been made on compositions and methods for exterminating and controlling insect pests that adversely affect plant growth. Patent Document 1 proposes a fungus belonging to the genus Trichoderma having acaricidal activity. Patent Document 2 proposes an acaricidal composition containing platinum particles and metal particles other than platinum particles, and a mite-proof member and a mite-proof method using the composition.

WO2014/083690 WO2017/082201 WO2013/038575

In addition to the above-mentioned patent documents, there is a need for techniques related to acaricidal use of microorganisms other than the genus Trichoderma.

Here, Patent Document 3 proposes a method for suppressing the growth of plant pathogenic bacteria using bacteria belonging to the genus Collimonas. It has not been.

Accordingly, an object of the present invention is to provide a new use of bacteria belonging to the genus Corymonas.

The invention of claim 1 is an acaricidal composition containing a bacterium belonging to the genus Collimonas and having accession number NITE P-1104 .

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide new uses for bacteria belonging to the genus Colymonas.

Shows the results of acaricidal test on bean leaves using a culture solution of bacteria of the genus Colimonas, (a) results after the start of the test, (b) results after 24 hours, and (c) results after 48 hours. , (d) the result after 72 hours, and (e) the result after 96 hours. FIG. 2 relates to FIG. 1 and represents the average survival rate of ticks; FIG. 2, related to FIG. 1, represents the ratio of the number of eggs laid to the number of live mites. FIG. 2, related to FIG. 1, represents the ratio of the total number of eggs laid to the total population of ticks; (a) shows the results of acaricidal test on strawberry leaves using a culture solution of bacteria belonging to the genus Corymonas. (b) Mean survival rate of ticks and its standard deviation. With reference to FIG. 5, there are micrographs of strawberry leaves, in which (a) to (c) show the state of Leaf1, and (d) to (f) show the state of Leaf2.

An example of an embodiment of the present invention will be described below with reference to the accompanying drawings.

[Acaricidal composition]
The acaricidal composition of the present embodiment is a composition containing bacteria belonging to the genus Collimonas. The composition can be in various forms such as powder and liquid. Examples of the form of the powder include a form in which the bacteria belonging to the genus Corymonas are supported on a fine mineral powder, and the powder is formulated into known powders and wettable powders. In addition, examples of the liquid form include a form in which the culture solution of bacteria belonging to the genus Colymonas is formulated into a known liquid preparation.

Bacteria belonging to the genus Corymonas used in this embodiment were registered with the Patent Microorganism Depositary Center of the National Institute of Technology and Evaluation (2-5 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) dated June 9, 2011. 8), deposited under the accession number NITE P-1104 (hereinafter referred to as "D-25 strain"). Tables 1 to 3 show the mycological properties of the D-25 strain.

[Acaricidal and acaricidal test]
Acaricidal and acaricidal tests with the D-25 strain are shown in Examples 1 and 2.

(Preparation of Corymonas bacterium)
The D-25 strain was cultured with shaking in 1/10 TSB for 5 days. After culturing, the number of viable cells in the culture medium was measured by 3-point spotting.

(preparing ticks)
Spider mites (Tetranychus urticae) (purchased from Sumika Techno Service Co., Ltd.) were used in the test. A plastic container lined with paper towels was lined with several leaves of bean (Phaseolus vulgaris), and the spider mites were transferred to the bean leaves. Several leaves of green bean were placed on it, covered with a non-woven fabric, and the spider mites were reared while maintaining a predetermined humidity.

An insect breeding dish lined with wet paper towels was used as the container used for the test. The test was conducted in the following two types of treatment plots.

・Processing area 1. pretreatment area
The bean leaves used for the test were immersed in the D-25 strain culture solution for 5 seconds, after which the bean leaves were transferred to an insect bleeding dish and the solution was dried. After drying, spider mites were transferred to the bean leaves at a rate of 10 or more/leaf. The number of surviving spider mites and the number of eggs laid were determined every 24 hours after transfer of the mites.

・Processing area 2. dipped
Green bean leaves used for testing were infested with spider mites at a rate of 10 or more/leaf. After transferring the spider mites, the bean leaves were immersed in the D-25 strain culture solution for 5 seconds, after which the bean leaves were transferred to an insect bleeding dish and the solution was allowed to dry. After drying, the number of surviving spider mites and the number of eggs laid were measured every 24 hours.

Bean leaves were also immersed in distilled water and then transferred to an insect bleeding dish to transfer spider mites. This was used as a control. In order to prevent spider mites from escaping from the green bean leaves, the green bean leaves were surrounded by absorbent cotton containing moisture.

Three sets were prepared for each of the above treated sections and controls, and the test was conducted. The results are shown in FIGS. 1 to 4. FIG.

(Regarding distilled water treatment area)
As shown in FIGS. 1 to 4, the survival rate of spider mites was 80% or more even after 96 hours in the distilled water treated area prepared as a control. The number of eggs laid was 258 in total after 96 hours, and when divided by the total number of eggs, the number of eggs laid was 6 per individual.

(Regarding the pretreatment area)
As shown in FIGS. 1 to 4, the survival rate of spider mites was greatly reduced between 48 and 72 hours in the pretreatment plots. After that, it leveled off, and the survival rate was 30% after 96 hours. The number of eggs laid was 175 in total after 96 hours, which was 4.5 eggs/individual when divided by the total number of eggs.
The survival rate of spider mites was lower than that of the distilled water treatment, but no significant difference was observed in the number of eggs laid.

(Regarding the immersion area)
As shown in FIGS. 1 to 4, in the immersion plot, the survival rate of spider mites was far below 50% between 48 and 72 hours, and decreased to about 12% after 96 hours. The number of eggs laid was 48 after 96 hours, and when divided by the total number of eggs, the number of eggs laid was 1.1/individual.

The D-25 strain culture described in Example 1 was diluted 100 times. Two strawberry leaves owned by a strawberry farmer were randomly selected and cut into 2 cm squares to prepare Leaf-1 and Leaf-2. A diluted culture solution of the D-25 strain was sprayed on each leaf (sprayed on July 14, 2017) to observe the survival of spider mites. The results are shown in FIGS. 5 and 6. FIG.

As shown in FIGS. 5 and 6, it was confirmed that 80-90% of spider mites died within 48 hours after spraying. In addition, there were no adult spider mites, and only juveniles were confirmed. Furthermore, many of the eggs were shriveled, and only a few healthy eggs were confirmed.

From the experimental results of Examples 1 and 2, it was confirmed that the bacteria of the genus Corymonas have not only the ability to control conventionally known plant pathogenic fungi, but also acaricidal and acaricidal abilities.

Therefore, acaricidal effect can be obtained by applying a composition comprising a colimonas bacterium to mites and/or their habitats. In addition, by using a composition containing bacteria of the genus Corymonas, it is possible to impart an anti-mite function to plants. In particular, when the strain of the bacterium belonging to the genus Corymonas is the D-25 strain, the above effects are remarkably exhibited.

Claims (3)

Acaricidal composition comprising a bacterium belonging to the genus Collimonas and having accession number NITE P-1104 . 3. A method of acaricidal treatment comprising the step of applying the acaricidal composition of claim 1 to mites and/or their habitats. A mite control method for imparting a mite control function to a plant using the acaricidal composition according to claim 1.

Images