JP7145728B2 - How to control Spodoptera litura - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for controlling Spodoptera litura.

Spodoptera litura is known as an agricultural pest, and is known to be extremely broad-feeding and to damage a wide variety of crops such as vegetables, potatoes, beans, fruit trees, and flowering plants.

In the control of Spodoptera litura, not only control by spraying general chemicals, but also sex pheromone substances of Spodoptera litura (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,11 - A control method by mating disruption using tetradecadienyl acetate is known (Non-Patent Document 1).

Pheromone preparations used for mating disruption should be fixed in the air by avoiding contact with the soil surface as much as possible to prevent adsorption of pheromone substances to the soil and decomposition of pheromone substances by soil microorganisms. is common.
In addition, it is known that Spodoptera litura has a high capture rate when a pheromone trap is installed at a position of 1 to 2 m above the ground. It is considered efficient to do so. In fact, in Non-Patent Document 1, the pheromone preparation is fixed to the tip of a plastic rod of about 120 cm for fear of deterioration in the flow of pheromone substances due to the height of the pheromone preparation becoming lower than the height of the plant body in the field. However, it is treated so that the pheromone preparation is always higher than the height of the plant body.

Mikio Takai, Takuya Hirose, Hisashi Takei, Uebo Shikoku, 1997, No. 32, page 22, right column, lines 19-26

However, as in Non-Patent Document 1, considering the height of the plant body, etc., the work of installing the pheromone formulation at a high place using a support or the like requires an installation tool such as a support in addition to the pheromone formulation. It is inconvenient as the area increases, and is disadvantageous in terms of cost.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for controlling Spodoptera litura that does not require consideration of the height of the plant and the ecology of Spodoptera litura.

The inventors have made intensive studies to solve the above problems, and found that, contrary to the above findings, even if a pheromone preparation comprising a pheromone substance of Spodoptera litura is placed on the surface of the soil or the surface of the soil surface covering material, Spodoptera litura may not be used. The inventors have found that it can be effectively controlled, and have completed the present invention.
According to one aspect of the present invention, a pheromone preparation comprising at least a pheromone substance of Spodoptera litura and a container that permeably stores the pheromone substance is placed on the surface of soil or the surface of a soil surface covering material in a field, and the pheromone substance into the field, wherein the pheromone substance is (Z,E)-9,12-tetradecadienyl= in a weight ratio of 1:99 to 50:50 A mixture of acetate and (Z,E)-9,11-tetradecadienyl acetate, wherein the container is a group consisting of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, biodegradable polymer and disintegrating polymer. There is provided a method for controlling Spodoptera litura, which is made of a polymer selected from.

According to the present invention, since the pheromone preparation is placed on the surface of the soil or on the surface of the soil surface covering material, Spodoptera litura can be effectively and economically controlled without considering the height of the plant and the ecology of Spodoptera litura. It becomes possible to suppress the generation of the next generation of Spodoptera litura.

First, the step of placing a pheromone preparation comprising at least a Spodoptera litura pheromone substance and a container on the surface of soil or the surface of a soil surface covering material in a field will be described.
Pheromone substances of Spodoptera litura include (Z,E)-9,12-tetradecadienyl acetate, (Z,E)-9,11-tetradecadienyl acetate, (Z)-9-tetradecenyl acetate , (E)-11-tetradecenyl=acetate and other sex pheromone substances. The pheromone substances of Spodoptera litura are not limited to compounds actually extracted from insect pests, but include industrially synthesized identical compounds, but industrially synthesized compounds are preferred from the viewpoint of economy. In addition, the pheromone substance of Spodoptera litura may contain unavoidable impurities in manufacturing.

Moreover, the pheromone substances of Spodoptera litura may be used, for example, only one kind, or two or more kinds may be used in combination. For example, when (Z,E)-9,12-tetradecadienyl=acetate and (Z,E)-9,11-tetradecadienyl=acetate are used in combination, (Z,E)-9,12 The mixing ratio (weight ratio) of -tetradecadienyl acetate and (Z,E)-9,11-tetradecadienyl acetate is preferably 1:99 to 99 from the viewpoint of the reported natural composition. :1, more preferably 1:99 to 50:50, more preferably 5:95 to 25:75.

Additives such as a diluent, a polymerization inhibitor, an antioxidant and an ultraviolet absorber may be added to the pheromone substance of Spodoptera litura. Each additive may be used in combination of two or more. Moreover, each additive can use a commercial thing.
Diluents include dodecyl acetate, tetradecyl acetate, hexadecyl acetate, 1-dodecanol, 1-tetradecanol, 1-hexadecanol and the like.
Polymerization inhibitors include 2,2′-methylenebis(4-methyl-6-t-butylphenol) and the like.
Antioxidants include 2,6-di-tert-butyl-4-methylphenol, butylhydroxytoluene, butylhydroxyanisole, hydroquinone, vitamin E and the like.
UV absorbers include 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-octoxybenzophenone, 2-(3,5 -di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2,5′-di-t-butylhydroquinone and the like.
The amount of each additive to be added varies depending on the usage environment and the like, but is preferably 0.1 to 6.0 parts by weight with respect to 100 parts by weight of the pheromone substance of Spodoptera litura.

The container provided with the pheromone preparation is not particularly limited as long as it can contain the pheromone substance of Spodoptera litura in a releasable manner, but is preferably made of a polymer. In order to release the stored pheromone substance to the field, the container may be at least partly made of a polymer permeable to the pheromone substance, and preferably entirely made of a polymer permeable to the pheromone substance.
The polymer is not particularly limited as long as it can permeate the pheromone substance of Spodoptera litura, and includes polyolefin plastics, biodegradable polymers, and degradable polymers. A biodegradable polymer is preferable from the viewpoint of omitting the trouble of installing and recovering it. Two or more types of polymers may be used in combination. In addition, a commercially available polymer may be used, or a synthesized polymer may be used.

Polyolefin plastics include polyethylene, polypropylene, ethylene-vinyl acetate copolymers, and the like.
The content of vinyl acetate units, which are vinyl acetate-derived repeating units, in the ethylene-vinyl acetate copolymer is preferably 0.5 to 10% by weight, more preferably 0.5 to 6%, from the viewpoint of release performance and processability. % by weight, more preferably 0.5 to 3% by weight. The weight average molecular weight (Mw) of the ethylene-vinyl acetate copolymer is not particularly limited, but is preferably 50,000 to 500,000 from the viewpoint of release performance and workability. The weight average molecular weight (Mw) of the ethylene-vinyl acetate copolymer can be measured by polystyrene-equivalent gel permeation chromatography (GPC).

Biodegradable polymers are enzymatically degradable polymers that are completely degraded by microorganisms in soil. The biodegradable polymer includes at least one dicarboxylic acid selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, fumaric acid, maleic acid and terephthalic acid, ethylene glycol and propane. Condensation polymer with at least one polyol selected from diol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, decanediol, lactic acid, hydroxyvaleric acid, hydroxycaproic acid and hydroxycapric acid and at least one kind of condensation polymer selected from the above, or an aliphatic polyester thermoplastic polymer such as polycaprolactone obtained by ring-opening polymerization of ε-caprolactone.

Specific examples of biodegradable polymers include polyethylene adipate, polyethylene succinate, polybutylene adipate, polybutylene succinate, polybutylene terephthalate, polylactic acid, poly-3-hydroxybutyrate, poly-3-hydroxyhexanoate, and the like. and one or more of these, preferably copolymers composed of two of these, such as polybutylene adipate succinate, polybutylene adipate terephthalate, polyethylene terephthalate succinate, poly-3-hydroxybutyrate- 3-hydroxyhexanoate and the like.

Further, a copolymer or a blend polymer containing an aliphatic polyester-based thermoplastic polymer as a main component is, in the case of a copolymer, all monomer units forming the aliphatic polyester-based thermoplastic polymer to form the copolymer. It is preferably contained in the monomer units in an amount of 50% by weight or more, and in the case of a blend polymer, the fatty acid polyester type thermoplastic polymer is contained in an amount of 50% by weight or more among the two or more polymers to be mixed.

A degradable polymer is an oxidatively decomposable polymer that is slowly degraded by soil microorganisms, ultraviolet rays, or the like. Examples of disintegrating polymers include polyethylene, polypropylene, nylon, polystyrene, polyvinyl chloride, polyvinyl acetate, or copolymers containing these constituents, to which biodegradable components, decomposition accelerators, or both have been added. is mentioned.
Examples of biodegradable ingredients include starch extracted from potato, rice, tapioca, corn, rye, barley, wheat, and the like.
Examples of the decomposition accelerator include transition metal compounds such as dithiocarbamate, rare earth compounds such as cerium oxide, and aromatic ketones such as benzophenone.

The container provided with the pheromone preparation is not particularly limited as long as it can stably hold the pheromone substance of Spodoptera litura and release the pheromone substance of Spodoptera litura into the atmosphere. .
From the viewpoint of uniformity of release of the pheromone substance of Spodoptera litura, a pheromone preparation comprising a tube-shaped container is preferable, and the inner diameter thereof is preferably 0.5 to 2.5 mm, more preferably 1.0 to 2.0 mm. The surface area is preferably 20 to 500,000 mm ² , more preferably 20 to 2000 mm ² , still more preferably 20 to 600 mm ² , and the film thickness is preferably 0.2 to 1.0 mm, more preferably 0.2 to 0.8 mm. Although the length of the tube-shaped container is not particularly limited, it is preferably 0.5 to 10,000 cm, more preferably 0.5 to 50 cm. Therefore, considering its portability, it is more preferably 0.5 to 5.0 cm, and particularly preferably 1.5 to 2.5 cm.

The amount of the pheromone substance of Spodoptera litura to be carried in the pheromone preparation is preferably 0.5 to 50,000 mg, more preferably 2 to 50,000 mg per pheromone preparation, from the viewpoint of the dose per unit area and the number of pheromone preparations installed. 250 mg, more preferably 4-40 mg.

In addition, the pheromone preparation is preferably sustained-release from the viewpoint of ensuring the release period of the pheromone substance throughout the outbreak period of Spodoptera litura.
From the viewpoint of the uniformity of the concentration of the pheromone substance in the field, the pheromone preparations are preferably placed evenly in the field. The installation density of the pheromone preparation is preferably 3 to 50,000/ha, more preferably 500 to 30, on the surface of the soil or the surface of the soil surface covering material, from the viewpoint of the dose per unit area and the release amount of the pheromone preparation. ,000/ha, more preferably 2,000 to 20,000/ha, particularly preferably 2,000 to 7,000/ha.

The release period of the pheromone formulation can be adjusted by appropriately determining the shape of the container of the pheromone formulation, the amount of pheromone substance supported, and the release amount and release rate of the pheromone substance, which will be described later. Since the duration of release in actual fields can fluctuate due to the influence of the weather environment, pheromone traps are used to check whether pheromone preparations are functioning, and if necessary, new pheromone preparations are added to the field. may be installed.
In addition, when the pheromone preparation was placed on the soil surface or the surface of the soil surface covering material, the pheromone residual rate exceeded 50% even after about two months, so it was compared with the case where the pheromone preparation was placed in the air. can be used without problems.

In the present specification, "installing the pheromone formulation on the surface of the soil or the surface of the soil surface covering material in a field" means placing the pheromone formulation in direct contact with the soil surface or through a soil surface covering material covering the soil surface. It is installed so that it is in direct contact with the soil surface. Examples of ground covering materials include mulch sheets, reflective sheets, anti-grass sheets, anti-grass mats, rice straw, thatch, rice husks, wood chips, weeds, mountain grasses, and wild grasses.
The area ratio of the soil surface to the soil surface covering material surface in the field is not particularly limited, and is preferably 100:0 to 0:100, more preferably 90:10 to 50:50.
Further, when the container provided with the pheromone preparation is tube-shaped, it may be placed upright on the surface of the soil or the surface of the soil surface covering material, or may be placed on its side.

Next, the step of releasing the pheromone substance of Spodoptera litura from the pheromone preparation to the field will be described.
The amount of pheromone substances released from Spodoptera litura cannot be generalized depending on the field environment, weather conditions, etc., but is not particularly limited, and from the viewpoint of the dosage per unit area and the number of pheromone preparations installed, it is preferably 0.1 to 0.1. 10 g/ha/day, more preferably 0.15 to 1.00 g/ha/day. In particular, it has been found that Spodoptera litura can be controlled by installing it on the surface of the soil or the surface of the soil surface covering material, even with a smaller release amount, preferably 0.15 to 0.40 g/ha/day.
The release rate of one pheromone preparation under an environment of 25° C. and a wind speed of 0.3 m/sec is preferably 0.030 to 200 mg/day/tube, more preferably 0.030 to 200 mg/day, from the viewpoint of the number of installed pheromone preparations. 1.000 mg/day/book, more preferably 0.030 to 0.090 mg/day/book, still more preferably 0.045 to 0.070 mg/day/book.
The release rate of the pheromone substance from the pheromone preparation of Spodoptera litura, for example, is the addition of a diluent to the pheromone substance, the material of the container, the shape (in the case of a tube-shaped container, the inner diameter, surface area, film thickness, length, etc.), etc. can be adjusted by

Crops cultivated in the field include eggplants, tomatoes, green peppers, peppers, and other solanaceous plants, okra, mallow such as morokheiya, cucurbitaceae, such as cucumbers, pumpkins, and zucchini, and cruciferous plants, such as cabbage. , soybeans, adzuki beans, etc., allium subfamily such as green onions, taro family such as taro, asparagus etc., strawberries, flowering plants and the like.

As described above, there is provided a method for controlling Spodoptera litura by placing a pheromone preparation containing a pheromone substance of Spodoptera litura on the surface of soil or the surface of a soil surface covering material in a field.

EXAMPLES Examples and comparative examples of the present invention will be described in detail below, but the present invention is not limited to these.
<Preparation of Pheromone Preparation A>
For 20.9 mg of a 9:91 (weight ratio) mixture of (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,11-tetradecadienyl acetate, 2- (2′-Hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole (HBMCBT), 2,6-di-tert-butyl-4-methylphenol (BHT), 95: Polybutylene adipate succinate (Bionol #3001, Showa Denko Co., Ltd.), which is a biodegradable polymer with an inner diameter of 1.56 mm, a film thickness of 0.35 mm, and a length of 2.0 cm, was mixed at a ratio of 2:3 (weight ratio). A pheromone preparation A was produced by sealing 22.0 mg of the product in a tube-shaped container manufactured by ).

<Preparation of Pheromone Preparation B>
Also, with respect to 170.0 mg of a 9:91 (weight ratio) mixture of (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,11-tetradecadienyl acetate, 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole (HBMCBT), 2,6-di-tert-butyl-4-methylphenol (BHT), Pheromone formulation B was produced by mixing at 95:2:3 (weight ratio) and enclosing 179 mg in a polyethylene tubular container having an inner diameter of 1.17 mm, a film thickness of 0.65 mm and a length of 20.0 cm. Pheromone preparation B was designed so that the amount released under an environment of 25°C and a wind speed of 0.3 m/sec was equivalent to 11,000 bottles/ha of pheromone preparation A and 1,000 bottles/ha of pheromone preparation B. .

<Release test of pheromone preparation A>
Thirty pheromone preparations A were evenly placed on the surface of the soil or on the surface of the soil covered with a mulch sheet (surface of the mulch sheet), and the remaining amount of the pheromone substance was confirmed for each elapsed day. Table 1 shows the residual rate of pheromone substances. In Table 1, "Z9E11-14: Ac" is (Z, E) -9,11-tetradecadienyl acetate, and "Z9E12-14: Ac" is (Z, E) -9,12-tetradecadienyl acetate. represents enyl acetate.
After 28 days and 63 days, 10 pheromone preparations placed on the soil surface or on the surface of the soil covered with a mulch sheet were collected, and the contents of the pheromone preparations were removed using acetone. It was calculated by averaging the values measured by the internal standard method/gas chromatogram analysis.

As shown in Table 1, even when the pheromone preparation was placed on the soil surface or on the soil surface covered with a mulch sheet, the pheromone substance could be released over a period of about two months. It was confirmed that there were no problems in use.

<Mating disruption test of Spodoptera litura>
Examples 1 and 2 and Comparative Example 1
A field in which pheromone preparation A was placed on the surface of the soil and on the surface of the mulch sheet (Example 1), a field in which pheromone preparation A was placed on the surface of the soil and on the surface of the mulch sheet (Example 2), and a field in which pheromone preparation B was attached to a support. A mating disruption test of Spodoptera litura was conducted in a field (Comparative Example 1) set at a position about 1 m from the soil surface. In Examples 1 and 2 and Comparative Example 1, the area ratio of the surface of the soil on which the pheromone preparation was placed and the surface of the mulch sheet was 75:25. In addition, all the pheromone preparations were placed evenly on their sides.
In both cases, the field area was about 1.5a, and the test period was overnight (around 18:30 to around 6:00). Eggplants, tomatoes, green peppers, green peppers, okra, morokheiya, cucumbers, pumpkins, zucchini, cabbages, soybeans, adzuki beans, green onions, and asparagus were grown in the fields. The ridges of eggplant, tomato, green pepper, pepper, okra, and cucumber were covered with a mulch sheet, and part of the pheromone preparation was also placed on the surface of the mulch sheet.
The effect of the mating disruption test was evaluated by measuring the mating rate. The mating rate was measured by counting the presence or absence of mating of 16 virgin females of Spodoptera litura, whose wings were tied to posts at a position of about 70 cm from the soil surface with a thin thread of about 30 cm in the center of the field. did.
Table 2 shows the release rate of pheromone production A and B under an environment of 25° C. and wind speed of 0.3 m/sec, the number of plants installed in the field test, the amount of pheromone substance released, and the mating rate.

Since Example 1 showed the same mating rate as Comparative Example 1, the mating disruption effect of Spodoptera litura was confirmed even when the pheromone preparation was placed on the surface of the soil and the surface of the mulch sheet.
In addition, since Example 2 showed the same mating rate as Comparative Example 1, sufficient mating disruption can be achieved even when the pheromone preparation is placed on the surface of the soil and the surface of the mulch sheet and the amount released is reduced. was confirmed.
As a means of confirming the mating disruption effect, a method of placing pheromone traps in the field and confirming the amount of attraction (confirmation of attraction inhibition effect), and placing reared virgin females in the field at night and collecting them the next morning to check the presence or absence of mating. A connecting female method to confirm (confirmation of mating inhibition effect) can be mentioned. In particular, the tethered female method is an effective means of directly evaluating the effects on mating behavior in the natural world because the females themselves are used.

Claims (4)

At least the step of placing a pheromone formulation comprising at least a pheromone substance of Spodoptera litura and a container that permeably stores the pheromone substance on a soil surface or a surface of a soil surface covering material in a field to release the pheromone substance into the field. A method for controlling Spodoptera litura,
the pheromone substance is (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,11-tetradecadienyl acetate in a weight ratio of 1:99 to 50:50; is a mixture of
A method for controlling Spodoptera litura, wherein the container is made of a polymer selected from the group consisting of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, biodegradable polymer and disintegrating polymer. The method for controlling Spodoptera litura according to claim 1, wherein the release amount of the pheromone substance of Spodoptera litura is 0.15 to 0.40 g/ha/day. The method for controlling Spodoptera litura according to claim 1 or claim 2, wherein the container is a tubular container having a length of 0.5 to 5.0 cm. 4. The container is made of a biodegradable polymer selected from the group consisting of polybutylene adipate succinate, polybutylene adipate terephthalate, polyethylene terephthalate succinate and poly-3-hydroxybutyrate-3-hydroxyhexanoate. The method for controlling Spodoptera litura according to any one of 1 to 3.