Heating transpiration composition, and method for exterminating harmful arthropods using same

Abstract

The present invention provides a heat transpiration composition characterized by having excellent ability in exterminating harmful arthropods and by comprising a natural pyrethrin and a pyrethroid compound, and characterized in that the weight ratio of an active ingredient of the natural pyrethrin and the pyrethroid compound is within a range of 20:1 to 200:1.

Description

Composition for thermal evaporation and method for exterminating harmful arthropods using the same

[0001] This patent application claims priority under the Paris Convention to and the benefit of Japanese Patent Application No. 2021-063990 (filed April 5, 2021), the entire contents of which are incorporated herein by reference. The present invention relates to a composition for thermal evaporation containing natural pyrethrins and pyrethroids, and a method for controlling arthropod pests using the same.

[0002] Various methods have been investigated for the purpose of exterminating harmful arthropods. For example, Patent Document 1 describes that a certain type of composition for thermal evaporation has an effect of exterminating mosquitoes.

[0003] Japanese Patent Application Publication No. 9-268104

[0004] However, the composition for heating and evaporation may not always have sufficient efficacy in exterminating harmful arthropods.

[0005] The present inventors have conducted research to provide a composition for thermal evaporation that is effective in exterminating harmful arthropods, and as a result, have found that a composition for thermal evaporation containing natural pyrethrins and pyrethroid compounds in a specific ratio exhibits excellent effectiveness in exterminating harmful arthropods, thereby completing the present invention.

[0006] The present invention includes, but is not limited to, the following aspects: 1. A composition for thermal evaporation containing natural pyrethrin and a pyrethroid compound, wherein the weight ratio of the active ingredient of the natural pyrethrin to the pyrethroid compound is in the range of 20:1 to 200:1. 2. The composition for thermal evaporation according to the above item 1, wherein the pyrethroid compound has a vapor pressure of 0.00001 Pa to 0.1 Pa at 25°C. 3. The composition for thermal evaporation according to the above item 1 or 2, wherein the pyrethroid compound is at least one pyrethroid compound selected from the group consisting of metofluthrin, dimefluthrin, transfluthrin, profluthrin, mepafluthrin, heptafluthrin, tetramethylfluthrin, and lenofluthrin. 4. Incense sticks comprising the composition according to any one of the above items 1 to 3. 5. A method for exterminating mosquitoes using the composition or incense stick according to any one of the above items 1 to 4. 6. 6. A mat preparation comprising the composition described in any one of the preceding items 1 to 3. 7. A method for exterminating mosquitoes using the composition or mat preparation described in any one of the preceding items 1 to 3 and 6. 8. A pest control preparation for thermal evaporation comprising the composition described in any one of the preceding items 1 to 3. 9. A method for exterminating mosquitoes using the composition or pest control preparation for thermal evaporation described in any one of the preceding items 1 to 3 and 8.

[0007] The composition for thermal evaporation of the present invention exhibits excellent efficacy.

[0008] The natural pyrethrins used in the present invention contain six active compounds: pyrethrin I, pyrethrin II, cinerin I, cinerin II, jasmoline I, and jasmoline II. Natural pyrethrins are typically available as pyrethrum dry powder or as an extract obtained by extracting only the flower buds of pyrethrum (scientific names: Tanacetum cinerariifolium or Chrysanthemum cinerariaefolium) from which the flower buds have been harvested, dried, and pulverized, using an appropriate solvent capable of dissolving the active ingredients, such as an organic solvent such as methanol. In addition to the six compounds, natural pyrethrins may also contain plant-derived impurities (such as fatty acids and flavonoids).In addition to the white daisy, other plants known to produce natural pyrethrins include Calendula officinalis, Chrysanthemum coccinum, Tagetes erecta, Tagetes minuta, Zinnia elegans, and Zinnia linnearis (Reference 1: Adnane, H. Alain, C. & Chantal, B. 2000. The Production of Pyrethrins by Plant Cell and Tissue Cultures of Chrysanthemum cinerariaefolium and Tagetes Species. Critical Reviews in Plant Sciences, 19(1):69-89; Reference 2: Kudakasseril, GJ and Staba, EJ 1988. Insecticidal phytochemicals. In: Cell Culture and Somatic Cell Genetics of Plants. pp. 537-552. Constabel, F. and Vasil, IK, Eds., Academic Press, New York, Reference 3: John E. Casida, Gary B. Quistad. 1995. PYRETHRUM FLOWERS, Production, Chemistry, Toxicology, and Uses. pp. 123-125, Oxford University Press.).

[0009] The plant species and varieties that serve as the source of the natural pyrethrins used in the present invention are not limited to those mentioned above. The cultivation method, cultivation conditions (weather, place of origin, soil type, etc.), harvest time, harvest part, harvesting method, washing method, extraction method, and purification method of the plant are not particularly limited. The natural pyrethrins used in the present invention also include, for example, natural pyrethrins obtained using a vector into which a gene encoding a pyrethrin biosynthetic enzyme has been inserted.

[0010] The weight ratios of the six types of compounds, pyrethrin I, pyrethrin II, cinerin I, cinerin II, jasmolin I, and jasmolin II, in natural pyrethrins are not particularly limited, and can be set at any weight ratio within the range of 0.001 to 99%, respectively. However, the natural pyrethrins are typically contained in weight ratios of 10 to 70% pyrethrin I, 10 to 70% pyrethrin II, 1 to 20% cinerin I, 1 to 20% cinerin II, 1 to 20% jasmolin I, and 1 to 20% jasmolin II.

[0011] Examples of natural pyrethrins include those containing pyrethrin I (total amount of pyrethrin I, cinerin I, and jasmolin I) and pyrethrin II (total amount of pyrethrin II, cinerin II, and jasmolin II) in an amount of 20 to 40% of pyrethrin I and 12 to 31% of pyrethrin II. The total amount of pyrethrin I and pyrethrin II in natural pyrethrins is usually 10 to 99%, preferably 15 to 90%, and more preferably 20 to 85%.

[0012] Natural pyrethrins are usually plant extracts, and therefore may contain, in addition to the six compounds mentioned above, plant-derived impurities as well as auxiliary ingredients such as solvents and stabilizers. Petroleum-based and vegetable oil-based solvents can be used, and synthetic and natural stabilizers can be used.

[0013] The active ingredients of natural pyrethrins in the present invention refer to pyrethrins I and II, and the weight ratio of the active ingredients of natural pyrethrins to pyrethroid compounds in the range of 20:1 to 200:1 is defined as the ratio of the total weight of pyrethrins I and II to the weight of pyrethroid compounds in the range of 20:1 to 200:1.

[0014] Examples of pyrethroid compounds used in the present invention include those described in the reference (The Pesticide Manual, Eighteenth Edition, J.A. Turner, British Crop Production Council, ISBN 978-1-9998966-1-4). From the viewpoint of volatility, pyrethroid compounds having a vapor pressure of 0.00001 Pa to 0.1 Pa at 25°C are preferred. More specifically, from the viewpoints of volatility and efficacy, examples include at least one compound selected from the group consisting of metofluthrin, dimefluthrin, transfluthrin, profluthrin, mepafluthrin, heptafluthrin, tetramethylfluthrin, and lenofluthrin. The vapor pressure is measured using the method described in Example 1 of JP-A 2006-284560.

[0015] The composition for thermal evaporation of the present invention can also be described as an insecticidal composition for thermal evaporation.

[0016] The following describes a formulation using the composition for thermal evaporation of the present invention. Examples of formulations using the composition for thermal evaporation include incense sticks, mosquito repellent mats, and pest control formulations for thermal evaporation. However, it is not intended that the formulations be limited to the configurations described in the embodiments described below.

[0017] <Incense>

[0018] The incense stick of the present invention typically comprises the above-mentioned composition for thermal evaporation, a carbonized base material, a combustion assisting agent, a bulking agent, a binder, and the like.

[0019] Specific examples of the carbonized substrate include plant-derived carbonized substrates such as charcoal, bamboo charcoal, plant-based activated carbon, coconut shell charcoal, and coffee grounds charcoal, as well as non-plant-derived carbonized substrates such as carbon black, graphite, acetylene black, coal-based activated carbon, and petroleum-based activated carbon, with plant-based carbonized substrates being particularly preferred. These are typically used alone or in combination of two or more.

[0020] Examples of combustion-supporting agents include dried plant powders such as wood flour, tabu (bark powder of the tabu tree), lees powder (pyrethrum extract powder), citrus peel powder, tea powder, palm oil powder, coconut shell powder, and walnut shell powder, and carbon powders such as charcoal powder, activated carbon powder, and coal powder, and these can be used alone or in combination of two or more.

[0021] Examples of the extender include diatomaceous earth, talc, clay, kaolin, etc. These extenders are usually used alone or in combination of two or more.

[0022] Examples of binders include polymeric compounds such as tabu flour, starch (gelatinized starch, tapioca starch, corn starch, wheat starch, etc.), casein, siamese flour, methyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol, and these are usually used alone or in combination of two or more.

[0023] The amounts of the carbonized base material, combustion enhancer, bulking agent, binder, etc. can be freely adjusted depending on the desired quality, but the total amount of these ingredients should be 85% by weight or more, more preferably 90% by weight or more, based on the weight of the entire mosquito coil.

[0024] The incense of the present invention can be obtained, for example, by adding an appropriate amount of water to a mixture containing the thermal vaporization composition and the incense base material, kneading the mixture, molding the mixture using an extruder, a punching machine, etc., and then drying naturally or by heating. It is also possible to mold only the incense base material without directly mixing the thermal vaporization composition into the mixture containing the incense base material, and then coat or spray the liquid containing the thermal vaporization composition on the molded incense base material.

[0025] The shape of the incense coil of the present invention is not particularly limited, but the shape of the long-lasting mosquito coil can be selected appropriately depending on the purpose of use, such as rod, spiral, cone, or plate, with rod, spiral, or plate shapes being preferred. The size is also not particularly limited, but for example, if the incense coil is rod-shaped, it is preferably set to a total length of 100 mm or less, a thickness of 7 mm or less, and a weight of 5 g or less, and more preferably a total length of 20 to 90 mm, a thickness of 2 to 5 mm, and a weight of 0.2 to 3 g. If the incense coil is spiral-shaped, it is preferably set to a total length of 150 cm or less, a thickness of 7 mm or less, and a weight of 50 g or less, and more preferably a total length of 30 to 90 cm, a thickness of 2 to 5 mm, and a weight of 5 to 20 g. In the case of spiral-shaped incense coils, the size is typically about 12 cm in diameter and 3 to 5 mm thick, for a pair of coils.

[0026] In actual use, incense is usually given a scent appropriate for the incense, and recently, various volatile fragrance ingredients have been added to achieve aromatic and relaxing effects. Various fragrance ingredients can also be added to the incense of the present invention to achieve aromatic and relaxing effects. Examples of fragrance ingredients include galaxolide, musk ketone, hexyl cinnamic aldehyde, isoe super, methyl dihydrojasmonate, ethylene brassylate, geraniol, methyl atralate, hexyl salicylate, tricyclodecenyl acetate, orange crystal, ambroxan, tonalide (6-acetyl-1,1,2,4,4,7-hexamethyltetralin), γ-undecalactone, cashmeran, calone, heliotropin, dihydroindenyl-2,4-dioxane, α-methyl-2,4-dioxane, α-methyl-1,1,2,4,4,7-hexamethyltetralin ... Examples of fragrance ingredients include α-isomethyl ionone, indole, methyl cedryl ketone, methyl β-naphthyl ketone, rosephenone, coumarin, vanillin, styrax resinoid, benzyl benzoate, undecanal, benzyl salicylate, ionone, α-ionone, β-ionone, lily aldehyde, 3,5-dinitro-2,6-dimethyl-4-t-butylacetophenone, acetyl cedrene, 2-cyclohexylidene-2-phenylacetaldehyde, isolongifolanon, and cis-3-hexenol. These fragrance ingredients can be used alone or in combination. The content of the fragrance ingredient is preferably 0.001 to 5 wt %, more preferably 0.01 to 1 wt %, based on the total weight of the incense stick. If the content of the fragrance ingredient is less than 0.001 wt %, the fragrance may not be sufficiently fragrant. If the content of the fragrance component exceeds 5% by weight, the odor or irritation may be too strong.

[0027] The incense of the present invention may contain other ingredients such as antifungal agents, preservatives, stabilizers, efficacy enhancers, deodorizers, etc. Examples of antifungal agents or preservatives include dehydroacetates, sorbates, p-hydroxybenzoates, etc. Examples of stabilizers include 2,6-di-tert-butyl-4-methylphenol (BHT), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, etc. The addition of such stabilizers not only improves the stability of the composition for thermal evaporation over time during storage, but also significantly enhances its stability during smoking, and can also contribute to improving the sustained efficacy of the composition for thermal evaporation after evaporation. The stabilizer is preferably added in an amount of 0.01 to 0.5 times the amount of the composition for thermal evaporation. Examples of potency enhancers include piperonyl butoxide and N-(2-ethylhexyl)-bicyclo[2,2,1]hept-5-ene-2,3-dicarboximide. The incense of the present invention can also contain coloring agents such as malachite green and food additives (e.g., Food Blue No. 1, Food Yellow No. 4, and Food Red No. 106).

[0028] <Mat Preparation> The mat preparation of the present invention can be produced, for example, by impregnating a fibrous carrier or a porous carrier with a solution obtained by mixing the heat-transferable composition with a solvent, a pigment, an antioxidant, a synergist, a stabilizer, a fragrance, etc. The mat preparation can be used, for example, as an electric mosquito repellent mat.

[0029] Examples of fibrous carriers include natural fibers such as pulp, cellulose, and cotton; synthetic fibers such as polyester and acrylic; and inorganic fibers such as glass fiber and asbestos. Examples of porous carriers include porous inorganic materials such as diatomaceous earth; porous magnetic materials such as unglazed clay; and porous resins such as urethane foam and polypropylene foam.

[0030] Electric mosquito repellent mats typically measure approximately 2.2 cm × 3.5 cm × 0.28 cm, but are not limited to this shape, and the amounts and ratios of the heat-transmittable composition and other ingredients to be blended can be adjusted appropriately to suit changes in the shape, size, thickness, etc. In the present invention, the content of the heat-transmittable composition per 2.2 cm × 3.5 cm × 0.28 cm mat varies depending on the type and content of the heat-transmittable composition, the duration of use of the electric mosquito repellent mat, etc., but is usually about 1 to 2000 mg, preferably about 1 to 100 mg.

[0031] <Pest Control Formulation for Thermal Transpirability> The pest control formulation for thermal transpirability of the present invention is a formulation that can be used in a thermal transpirability type insecticide device, for example, as shown in FIG. 1. A solution 1 containing a thermal transpirability composition is filled into a liquid solution bottle 4. An absorbent wick 3 is partially immersed in the solution 1, allowing the absorbent wick to absorb the solution containing the thermal transpirability composition, and the upper part of the absorbent wick can be heated by a heating element 2. By indirectly heating the upper part of the absorbent wick to a temperature of about 60°C to about 135°C by the heating element 2, the thermal transpirability composition absorbed into the absorbent wick is evaporated into the atmosphere, thereby controlling pests. The pest control formulation for thermal transpirability of the present invention is not limited to the device shown in FIG. 1, and can be applied to any conventionally known thermal transpirability type insecticide device and exhibit excellent effects. Heat-transportation type insecticide devices to which the heat-transportation pest control formulation of the present invention can be applied are described, for example, in JP-B No. 52-12106, JP-A No. 58-45670, and JP-A No. 2012-176947.

[0032] In the pest control formulation for thermal evaporation of the present invention, the composition for thermal evaporation is prepared in the form of a solution (Solution 1) containing the composition for thermal evaporation. An oily or aqueous solvent is used as the solvent for preparing the pest control formulation for thermal evaporation. When an oily solvent is used, an oily solvent with a boiling point of 350°C or less is typically used. While various organic solvents, typically hydrocarbon solvents, can be used as the oily solvent, aliphatic hydrocarbons (paraffinic hydrocarbons and unsaturated aliphatic hydrocarbons) with a boiling point range of 150 to 350°C are particularly preferred. Examples of such solvents include deodorized kerosene, n-paraffin, isoparaffin (e.g., IP Solvent (manufactured by Idemitsu Kosan Co., Ltd.)), and Sowing Glue (manufactured by ENEOS). Examples of organic solvents other than the hydrocarbons mentioned above include glycerin, propylene glycol, methanol, acetone, xylene, chlorthene, isopropanol, and chloroform. When an aqueous solvent is used, glycol ethers and water are typically used. Examples of such glycol ethers include ethylene glycol ethers, propylene glycol ethers, and dialkyl glycol ethers, with ethylene glycol ethers being preferred. Among ethylene glycol ethers, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monopropyl ether are preferred. One or a mixture of two or more glycol ethers can be used. The weight ratio of glycol ether to water is typically in the range of 1:0.4 to 1:8.5, preferably 1:1 to 1:8.5, and more preferably 1:1.4 to 1:3.6. The concentration of the composition for thermal evaporation in the pest control formulation for thermal evaporation is typically about 6 to 80% by weight, preferably about 10 to 75% by weight, and more preferably about 15 to 50% by weight. The pest control formulation for thermal evaporation of the present invention may also contain other ingredients such as thickeners, surfactants, stabilizers, preservatives, and synergists.

[0033] Furthermore, the heating element (heating element 2) used in the heat evaporation type insecticide device is usually a heating element that generates heat when electricity is passed through it, but is not limited to this, and any known heating element can be used, such as an air oxidation heating element, a heating element that uses a platinum catalyst, etc.

[0034] The liquid-absorbent wick 3 is generally made of a porous material. Examples of such porous materials include inorganic powders such as clay, talc, kaolin, diatomaceous earth, gypsum, perlite, bentonite, acid clay, glass fiber, and asbestos, which are bound and molded with a sizing agent such as carboxymethyl cellulose, starch, gum arabic, gelatin, and polyvinyl alcohol. The liquid-absorbent wick may also contain dyes, preservatives, antioxidants, and the like, as appropriate. These additives can be incorporated, for example, by mixing the inorganic powder with the sizing agent during binding.

[0035]

[0036] Target pests for control by the heat-transferable composition of the present invention and formulations using the heat-transferable composition include various harmful insects, arthropods such as mites, and particularly harmful flying pests, such as Culex pipiens pallens, Culex tritaeniorhynchus, Culex quinquefasciatus, and Culex molestus, Aedes mosquitoes such as Aedes aegypti and Aedes albopictus, Anopheles mosquitoes such as Anopheles sinensis, midges, house flies such as Musca domestica, Musca domestica, and Musca canina, blow flies, flesh flies, Drosophila, moth flies, phorid flies, horseflies, black flies, stable flies, and midges. Among these, mosquitoes such as Culex pipiens, Aedes mosquitoes, and Anopheles mosquitoes are particularly suitable as target pests for control.

[0037] The present invention will be explained in more detail below by giving production examples and test examples, but the present invention is not limited to these examples.

[0038] Production Example 1 (Kneaded Incense Stick 1) 1 part by weight of natural pyrethrin, 0.05 part by weight of dimefluthrin, and 39 parts by weight of Tabu powder, 30 parts by weight of dregs powder, and 30 parts by weight of wood flour as combustion supporters were mixed, to which 0.3 parts by weight of green pigment was added, and the mixture was stirred and mixed uniformly. 120 parts by weight of water was then added and thoroughly kneaded. The kneaded mixture was formed into a sheet, punched into spiral shapes, and dried until the moisture content was about 7 to 10% by weight, to produce the incense stick preparation of the present invention.

[0039] Production Example 2 (Kneaded Incense Stick 2) 1 part by weight of natural pyrethrin, 0.05 part by weight of dimefluthrin, 50 parts by weight of charcoal as a carbonized substrate, 0.8 parts by weight of a mixed fragrance containing galaxolide, musk ketone, etc. as a fragrance component, 17 parts by weight of lees flour and 10.7 parts by weight of wood flour as combustion supporters, 3 parts by weight of diatomaceous earth as a bulking agent, and 14 parts by weight of pregelatinized starch and 3 parts by weight of carboxymethyl cellulose as binders were mixed, and 90 parts by weight of water was added and thoroughly kneaded. The kneaded mixture was extruded into a rod shape and then dried until the moisture content was about 7 to 10% by weight, producing the incense stick preparation of the present invention.

[0040] Production Example 3 (Mat Preparation 1) 10.5 parts by weight of natural pyrethrins, 0.5 parts by weight of transfluthrin, 39.5 parts by weight of acetyltributyl citrate, 39.5 parts by weight of isononyl adipate, 5 parts by weight of blue pigment, and 5 parts by weight of fragrance were mixed together to obtain a solution (120 mg). The solution was uniformly impregnated into an electric mat substrate (a fibrous carrier made of pulp and cotton linters) measuring 2.1 cm x 3.4 cm and 0.22 cm thick to prepare an electric mosquito repellent mat preparation of the present invention.

[0041] Production Example 4 (Mat Preparation 2) 8 mg of 1,4-dibutylaminoanthraquinone and 40 mg of 1,8-bis(phenylthio)dodecahydroanthraquinone were dissolved in 5 g of a solution consisting of 20.0 wt % natural pyrethrins, 1.0 wt % metofluthrin, 10 wt % dibutylhydroxytoluene, 25 wt % diisononyl adipate, 30 wt % tributyl acetate citrate and 14.0 wt % isoparaffin solvent (manufactured by Showa Shell Sekiyu K.K., trade name: Merveille 40), and 120 mg of the solution was uniformly impregnated into an electric mat substrate (a fibrous carrier made of pulp and cotton linters) measuring 2.2 cm x 3.5 cm and 0.28 cm thick to prepare an electric mosquito repellent mat preparation of the present invention.

[0042] Production Example 5 (Mat Preparation 3) 8 mg of 1,4-dibutylaminoanthraquinone and 40 mg of 1,8-bis(phenylthio)dodecahydroanthraquinone were dissolved in 5 g of a solution consisting of 50.0 wt % natural pyrethrins, 0.25 wt % metofluthrin, 15 wt % dibutylhydroxytoluene, 4.75 wt % diisononyl adipate, 20 wt % tributyl acetate citrate and 10 wt % isoparaffin solvent (manufactured by Showa Shell Sekiyu K.K., trade name: Merveille 40), and 500 mg of the solution was uniformly impregnated into an electric mat substrate (a fibrous carrier made of pulp and cotton linters) measuring 2.2 cm x 3.5 cm and 0.28 cm thick to prepare an electric mosquito repellent mat preparation of the present invention.

[0043] Production Example 6 (Mat Preparation 4) 8 mg of 1,4-dibutylaminoanthraquinone and 40 mg of 1,8-bis(phenylthio)dodecahydroanthraquinone were dissolved in 5 g of a solution consisting of 50.0 wt % natural pyrethrins, 0.25 wt % metofluthrin, 15 wt % dibutylhydroxytoluene, 4.75 wt % diisononyl adipate, 20 wt % tributyl acetate citrate and 10 wt % isoparaffin solvent (manufactured by Showa Shell Sekiyu KK, trade name: Merveille 40), and 2000 mg of the solution was uniformly impregnated into an electric mat base material (a fibrous carrier made of pulp and cotton linters) measuring 2.2 cm x 3.5 cm and 0.28 cm thick to prepare an electric mosquito repellent mat preparation of the present invention.

[0044] Production Example 7 (Pest control formulation 1 for thermal evaporation) 2.0 parts by weight of natural pyrethrin, 0.1 parts by weight of metofluthrin, and 9.965 parts by weight of IP Solvent 2028 (Idemitsu Kosan Co., Ltd., 50% distillation temperature approximately 233°C) were mixed with Soinglub N-15 (ENEOS Corporation, 50% distillation temperature approximately 265°C) to make 100 parts by weight, and the resulting solution was filled into a 45 mL plastic container, and a porous liquid-absorbing wick whose top could be heated with a heater was inserted via the inner stopper, thereby producing a pest control formulation for thermal evaporation of the present invention.

[0045] Production Example 8 (Pest control formulation 2 for thermal evaporation) 10.5 parts by weight of natural pyrethrin and 0.5 parts by weight of metofluthrin are mixed and dissolved in 89 parts by weight of deodorized kerosene, and the resulting solution is filled into a 45 mL polyvinyl chloride container. A porous liquid-absorbing wick (made by solidifying inorganic powder with a binder and sintering it) whose top can be heated with a heater is inserted via the inner stopper, thereby producing a pest control formulation for thermal evaporation of the present invention.

[0046] Production Example 9 (Pest control formulation 3 for thermal evaporation) 10.5 parts by weight of natural pyrethrin and 0.5 parts by weight of metofluthrin were mixed and dissolved in 50 parts of diethylene glycol monobutyl ether, 1.8 parts of dibutylhydroxytoluene, and 46.7 parts of water, and the resulting solution was filled into a 45 mL plastic container. A porous liquid-absorbing wick whose top could be heated with a heater was inserted via the inner stopper, thereby producing a pest control formulation for thermal evaporation of the present invention.

[0047] The effects of the present invention will be demonstrated below by test examples.

[0048] Preparation of Test Formulation (Incense Sticks) 75 parts by weight of wood flour, 5 parts by weight of Tabu flour, 5 parts by weight of lees flour, 10 parts by weight of Siamese flour, and 5 parts by weight of tapioca starch were mixed, and an appropriate amount of water was added and thoroughly kneaded. The kneaded mixture was molded into a sheet, punched into a spiral shape, and then dried until the moisture content was approximately 7 to 10% by weight to prepare blank incense sticks. A test compound solution diluted to a predetermined concentration in acetone was uniformly added dropwise to the obtained blank incense sticks, and the mixture was air-dried to prepare a test formulation.

[0049] Test Example 1: Twenty adult female Culex pipiens pallens were placed in a 4.5 cm diameter, 12 cm tall glass tube, and the top and bottom openings of the tube were secured with 16-mesh nylon netting using rubber bands. A 22 cm diameter, 83 cm tall metal tube was placed upright, and two glass tubes containing the mosquitoes were placed upright and secured to the top opening. The formulation prepared as described above was ignited and placed in the bottom opening of the metal tube. The number of mosquitoes knocked down was recorded after 6 minutes. The experiment was repeated three times to determine the knockdown rate (hereinafter referred to as the KD rate). The expected KD rate for a mixture of natural pyrethrins and each pyrethroid compound was calculated using Colby's formula and is shown in Table 1 below. The concentration of natural pyrethrins represents the concentration of the active ingredient in the natural pyrethrin. Theoretical expected value (%) based on Colby's formula = A + (100 - A) x B / 100 In the above formula, A and B represent the following numbers: A: KD rate (%) when only A is treated B: KD rate (%) when only B is treated

[0050]

[0051] Test Example 2: Twenty adult female Culex pipiens pallens were placed in a 4.5 cm diameter, 12 cm tall glass tube, and the top and bottom openings of the tube were secured with 16-mesh nylon netting using rubber bands. A 22 cm diameter, 83 cm tall metal tube was placed upright, and two glass tubes containing the mosquitoes were placed upright and secured to the top openings. The formulation prepared as described above was ignited and placed in the bottom opening of the metal tube. The number of knocked-down (KD) mosquitoes was recorded after 7 minutes. The experiment was repeated three times to determine the KD rate. The expected KD rates based on the KD rates for natural pyrethrins and each pyrethroid compound used alone were calculated using Colby's formula and are listed in Table 2 below.

[0052]

[0053] Test Example 3: Twenty adult female Culex pipiens pallens were placed in a 4.5 cm diameter, 12 cm tall glass tube, and the top and bottom openings of the tube were secured with 16-mesh nylon netting using rubber bands to enclose the tube. A 22 cm diameter, 83 cm tall metal tube was placed upright, and two glass tubes containing the mosquitoes were placed upright and secured to the top openings. The formulation prepared as described above was ignited and placed in the bottom opening of the metal tube. The number of knocked-down (KD) mosquitoes was recorded after 10 minutes. The experiment was repeated three times to determine the KD rate. The expected KD rates based on the KD rates obtained when natural pyrethrins and each pyrethroid compound were used alone were calculated using Colby's formula and are listed as expected values ​​in Table 3 below.

[0054]

[0055] As shown in Test Examples 1 to 3, the incense sticks of the present invention, which contain natural pyrethrins and each pyrethroid compound in a predetermined mixing ratio, have been shown to exhibit effects greater than those expected from the effects of natural pyrethrins or each pyrethroid compound alone.

[0056] Test Example 4: Twenty adult female Culex pipiens pallens were placed in a 4.5 cm diameter, 12 cm tall glass tube, and the top and bottom openings of the tube were sealed with 16-mesh nylon netting secured with rubber bands. A 22 cm diameter, 83 cm tall metal tube was placed upright, and two glass tubes containing the Culex pipiens pallens were placed upright and secured to the upper openings. A mat formulation of the present invention was prepared according to Formulation Examples 3 or 4. The mat formulation was placed in a commercially available insecticidal mat heater, placed at the lower opening of the metal tube, and heated. After 10 minutes, the number of Culex pipiens knocked down (KD) was recorded and the KD rate was calculated. It was confirmed that the mat formulation of the present invention, which contains natural pyrethrins and various pyrethroid compounds in a specified mixture ratio, exhibits greater efficacy than would be expected from the effects of natural pyrethrins or various pyrethroid compounds alone. Examples of heat evaporation compositions used in matte formulations that have been confirmed to be highly effective in this test example include the heat evaporation compositions shown in Table 4 below.

[0057]

[0058] Test Example 4 confirms that the mat preparation of the present invention, which contains natural pyrethrins and each pyrethroid compound in a predetermined mixing ratio, exhibits an effect greater than that expected from the effect exhibited by natural pyrethrins or each pyrethroid compound alone.

[0059] Test Example 5: Twenty adult female Culex pipiens pallens were placed in a 4.5 cm diameter, 12 cm high glass tube, and the top and bottom openings of the tube were sealed with 16-mesh nylon netting secured with rubber bands. A 22 cm diameter, 83 cm high metal tube was placed upright, and two glass tubes containing the Culex pipiens mosquitoes were placed upright and secured to the upper openings. A thermal vaporization insecticide formulation of the present invention was prepared according to Formulation Examples 7, 8, or 9. The thermal vaporization insecticide formulation was placed in the thermal vaporization insecticide device shown in Figure 1, placed at the lower opening of the metal tube, and heated. After 10 minutes, the number of Culex pipiens knocked down (hereinafter referred to as KD) was recorded to determine the KD rate. It has been confirmed that the pest control formulation for thermal evaporation of the present invention, which contains natural pyrethrins and each pyrethroid compound in a predetermined mixing ratio, exhibits an effect greater than that expected from the effect exerted by either natural pyrethrins or each pyrethroid compound alone. Examples of the thermal evaporation compositions used in the pest control formulation for thermal evaporation that have been confirmed to be highly effective in this test example include the thermal evaporation compositions shown in Table 5 below.

[0060]

[0061] Test Example 5 confirms that the pest control formulation for thermal evaporation of the present invention, which contains natural pyrethrins and each pyrethroid compound in a predetermined mixing ratio, exhibits a higher effect than would be expected from the effect of natural pyrethrins or each pyrethroid compound alone.

[0062] By using the composition for heating and evaporation of the present invention, harmful arthropods can be controlled.

Claims

1. A composition for thermal evaporation comprising natural pyrethrin and a pyrethroid compound, the weight ratio of the active ingredient of the natural pyrethrin to the pyrethroid compound being in the range of 20:1 to 200:

1.

2. 2. The composition for heating and evaporation according to claim 1, wherein the pyrethroid compound has a vapor pressure of 0.00001 Pa to 0.1 Pa at 25°C.

3. 2. The composition for heating and evaporation according to claim 1, wherein the pyrethroid compound is at least one pyrethroid compound selected from the group consisting of metofluthrin, dimefluthrin, transfluthrin, profluthrin, mepafluthrin, heptafluthrin, tetramethylfluthrin, and lenofluthrin.

4. An incense stick comprising the composition of claim 1.

5. A method for controlling mosquitoes, which uses the composition or incense stick according to any one of claims 1 to 4.

6. A mattifying agent comprising the composition according to claim 1.

7. A method for controlling mosquitoes, comprising using the composition or mat preparation according to any one of claims 1 to 3 and claim 6.

8. A pest control formulation for thermal evaporation comprising the composition according to claim 1.

9. A method for controlling mosquitoes, which uses the composition or the pest control formulation for thermal evaporation according to any one of claims 1 to 3 and claim 8.