JPH0378084B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for controlling tea pests.

In recent years, as a pest control method that does not cause environmental pollution, preparations that release insect pheromones slowly have been distributed outdoors, and by dispersing the pheromone into the atmosphere, insects are attracted to traps and then captured and killed, which is called mass trapping. So-called disturbance methods, which detect males and females and disrupt their mating behavior, are attracting attention. To control tea pests, for example, as described in Japanese Patent Publication No. 57-34973, a string-like preparation carrying pheromone is installed along the ridges of a tea plantation at the top of a tea tree, creating a pheromone atmosphere throughout the tea plantation. A disturbance method has been proposed that causes the formation of

However, conventionally known sustained-release pheromone preparations, including the preparation described in the above publication, are made by impregnating a suitable string-like carrier with pheromone, or by impregnating it with a polymer that is highly compatible with pheromone. By dissolving and containing the pheromone to form a uniform sheet and surrounding the sheet with a polymer film having low compatibility with the pheromone, sustained release of the pheromone is achieved. However, with the former formulation, there is a problem that the sustained release of the pheromone is insufficient and the pheromone is released over a short period of time, while with the latter formulation, although the sustained release of the pheromone is somewhat improved, However, there is a limit to the solubility of pheromone in polymers, and it is usually difficult to contain 30% by weight or more of pheromone. That is, if the polymer contains a large amount of dissolved pheromone exceeding 30% by weight, the polymer cannot form a sheet, so the pheromone content is usually suppressed to about 10% by weight. Therefore, with such a preparation, it is difficult to sustainably release the pheromone over a long period of time, and tea pests cannot be effectively controlled.

The present invention was made to solve the various problems described above, and by using a tape-shaped pheromone sustained release preparation having a novel structure,
To provide a method that is easy to apply, releases pheromone gradually at a substantially constant rate over a long period of time, and thus effectively controls tea pests.

In the method for controlling tea pests according to the present invention, a liquid pheromone having limited solubility in the polymer at room temperature is encapsulated as droplets in the micropores of a polymer membrane having a large number of independent micropores. The method is characterized in that a long tape-like preparation made of a membrane is installed along the ridges of a tea plantation, penetrating between the branches of the tea plants.

In the present invention, the pheromone includes the sex pheromone of tea pests that is liquid at room temperature and its sex pheromone-like compounds, and specifically includes Z-11-tetradecenyl acetate and the like.

The tape-shaped pheromone preparation used in the method of the present invention has a dense layer on the surface, and this dense layer is anisotropic in that it is integrally supported by a porous polymer layer having a large number of independent micropores. A long tape-like preparation consisting of a membrane having a structure, the micropores usually have a pore diameter in the range of 0.5 to 10μ, and
Demarcated by thin partition walls ranging from 0.1 to 5μ in thickness,
mutually independent. The pheromone is dispersed in the form of droplets within these micropores. Although the film thickness is not particularly limited, it is usually in the range of 10 to 500 microns, and the dense layer usually has a thickness of 1 to 100 microns. Therefore, since the membrane with the above structure has an extremely large porosity, it can contain up to about 70% by weight of pheromone, but in practical terms it can contain up to 50% by weight.
It is preferable to set it to about % by weight.

In the above formulation, the polymer needs to have limited solubility for the pheromone used, where solubility refers to the number of parts by weight of the pheromone that can be dissolved in 100 parts by weight of the polymer; , Limited solubility means that the pheromone is dissolved only in a range of 5 parts by weight or less per 100 parts by weight of the polymer, and in particular, a polymer in which the pheromone is dissolved in a range of 0.01 to 2 parts by weight is preferably used. It will be done.

Such polymers are appropriately selected depending on the pheromone used, and specific examples include polysulfone, polycarbonate, polystyrene,
Poly(meth)acrylic esters including polymethyl methacrylate, polyamides, polyvinylidene chloride, polyvinylidene fluoride, cellulose esters, regenerated cellulose, polyurethanes,
Examples include one or a mixture of two or more of polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polystyrene-polybutadiene block copolymer, and the like.

The above-mentioned pheromone preparation can dissolve both the pheromone and the polymer, and can dissolve a polymer and a pheromone that is liquid at room temperature and has limited solubility for the polymer at room temperature. The pheromone is dissolved in a readily volatile organic solvent, this solution is applied to the surface of a suitable support, the solvent is evaporated, and the pheromone is dispersed and contained in the form of minute droplets within the polymer film. obtained by.

The above-mentioned organic solvent must be able to dissolve both the pheromone and the polymer, be more volatile than the pheromone, and have a lower boiling point, and is selected as appropriate depending on the type of pheromone and polymer used. Specifically, for example, lower aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride, lower aliphatic alcohols such as methanol and ethanol, and their acetate esters, as well as acetonitrile, acetone, ethyl ether, One type or a mixture of two or more types can be mentioned, such as tetrahydrofuran. Preferably, lower aliphatic halogenated hydrocarbons such as methylene chloride are used.

The total concentration of the pheromone and the polymer in the solution consisting of the pheromone, the polymer, and the above-mentioned organic solvent is usually suitably 10 to 50% by weight, preferably 15 to 40% by weight. In the above solution, the pheromone is blended in an amount exceeding the solubility of the polymer. By applying a solution containing such a pheromone and a polymer onto an appropriate long support substrate, such as a resin film, metal foil, metal foil laminated paper, etc., and evaporating the organic solvent,
A tape-shaped pheromone preparation for use in the method of the present invention can be obtained. The temperature when evaporating the organic solvent is usually 0 to 100°C, preferably 15 to 70°C.
℃ range and below the boiling point of the solvent. Usually, room temperature is sufficient. In this way, as the organic solvent evaporates, phase separation occurs between the pheromone and the polymer, as the pheromone has only a limited solubility in the polymer, resulting in tiny droplets of the pheromone. is uniformly dispersed in the polymer matrix, and therefore the polymer has a large number of independent micropores, in which the pheromone is encapsulated, and on the surface of the polymer, As the solvent evaporates, the polymer concentration increases, and a dense layer is finally formed that is integrated with the porous membrane.

According to the tape-like preparation described above, the pheromone has limited solubility in the polymer and a dense layer is formed on the surface, so the pheromone in the micropores is absorbed into the polymer. It is released at a substantially constant and controlled rate over an extended period of time, since diffusion is suppressed and the dense layer on the surface limits release to the ambient atmosphere.

In the method of the present invention, the tape-shaped pheromone preparation as described above is installed along the longitudinal direction of the ridges of the tea plantation, penetrating between the branches of the tea plants. Therefore, pheromone is released in the tea plantation at a substantially constant rate over a long period of time, creating a stable pheromone atmosphere, which effectively disrupts communication between female and male adults.
In this way, pest control can be carried out over a long period of time.

Examples of the present invention are listed below, but the present invention is not limited to the examples in any way.

Example: Dissolve 3 parts of Z-11-tetradecenyl acetate and 15 parts of polysulfone in 100 parts of methylene chloride, and spread this solution between three layers: 150μ thick paper, 30μ thick aluminum foil, and 50μ thick polyethylene film. It is applied at room temperature onto the paper surface of a supporting substrate consisting of a layer laminate, left at room temperature to evaporate the methylene chloride,
A film with a thickness of about 100 μm containing about 15% by weight of the above acetate was formed on a supporting substrate. Furthermore, Z-11-
The solubility of tetradecenyl acetate in polysulfone is 0.8 parts. A cross section of a formulation comprising a membrane integrated onto such a support substrate is schematically shown in FIG. That is, the polymer membrane 1 has a dense layer on the surface and a large number of independent micropores 2 inside, and this membrane is a supporting base material made of a three-layer laminate of paper 3, aluminum foil 4, and polyethylene film 5. 6. As a result of scanning electron micrograph observation of the cross section of the membrane after the entire amount of attractant was released, the diameter of the micropores in the membrane was 0.5 to 10 μm, the thickness of the micropore partition wall was 0.1 to 5 μm, and the thickness of the micropores was 0.1 to 5 μm. The thickness of the compact layer was approximately 50μ.

The above preparation was left in an open atmosphere at 25° C., and changes over time in the amount of liquid pheromone released from the preparation were investigated based on the amount of decrease in Z-11-tetradecenyl acetate remaining in the preparation. As the results are shown in Figure 2, the pheromone moves at a substantially constant rate of about 100
It was released stably over a period of days.

The above preparation was cut into tapes with a width of 1 cm to obtain a pheromone sustained release preparation, which was then installed in every other ridge in a tea field so as to thread between the tea branches in the longitudinal direction of the ridge. The formulation was applied to the tea plantation. The required tape for the entire tea plantation was approximately 300 m, and the amount of pheromone released was approximately 270 mg/day.

One adhesive trap using pheromone as lure bait for the Chimpanzea cicada was set up in the center of each 10 are area of the above pheromone preparation application area and non-application area, and the traps were lured and captured over a two-month period from April to May. When comparing the number of insects in the non-applied area, there were 227 insects in the applied area, but only 1 in the applied area, confirming that the method of the present invention has a significant communication disruption effect. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing a pheromone preparation used in the method of the present invention, and FIG. 2 is a graph showing changes over time in the amount of Z-11-tetradecenyl acetate released from the preparation according to the present invention. . 1... Polymer membrane, 2... Micropore, 6... Supporting base material.

Claims (1)

[Claims] 1. A long tape consisting of a film body in which a liquid pheromone having limited solubility for the polymer at room temperature is encapsulated as droplets in the micropores of a polymer film having a large number of independent micropores. 1. A method for controlling tea pests, which comprises installing a preparation along the ridges of a tea field, penetrating between the branches of tea plants.