JP7644482B2 - Pest control methods - Google Patents

Description

The present invention relates to a method for controlling pests in a space using a pest control agent having transpiration properties.

For example, a pest control method is known in which a pest control agent having a vapor pressure of 2×10 ⁻⁴ to 1×10 ⁻² mmHg at 30° C. is used to control pests in a space, by releasing about 0.01 to 40 mg of a pest control agent per 8 tatami mat space, so that the pest control agent adheres to the inner surfaces of floors and walls, and the pest control agent adhered to the inner surfaces of floors and walls re-evaporates, thereby controlling pests in the space.

On the other hand, for example, Patent Document 2 discloses a method of preventing the intrusion of pests by applying a pest control agent selected from a pyrethroid compound that is difficult to evaporate.

JP 2009-35569 A JP 2016-155774 A

When using a pest control agent that evaporates at room temperature, as in Patent Document 1, there is the advantage that it can be evaporated throughout the entire space to exert its effect, but there is also the disadvantage that the agent may continue to be dispersed and wasted even when there are no pests in the space, and as a result, the duration of its effectiveness is relatively short. Therefore, the method in Patent Document 1 is used when pests are found in a space, or when it is thought that there is a high possibility that pests are present in the space.

On the other hand, when a pest control agent with low volatility is used as in Patent Document 2, although there is an advantage in that its effectiveness lasts for a relatively long time, there is a disadvantage in that since the pest control agent does not volatilize into the space, it cannot be effective throughout the entire space, and is only effective in the area where it is applied.

However, some types of pests may enter spaces to hibernate during the winter (when temperatures are low). In this regard, it may be possible to prevent pests from entering spaces using an intrusion prevention method such as that described in Patent Document 2, but in reality, it is often impossible to completely prevent pests from entering.

Even if pests are allowed to invade a space, if the intrusion is noticed immediately, there is a possibility that they can be eradicated by treating the space with a method such as that described in Patent Document 1. However, if the intrusion is noticed too late, the pests will enter gaps to hibernate, making them difficult to find, and there is a high possibility that the intrusion will go unnoticed. In this case, there is no opportunity to treat the space with a method such as that described in Patent Document 1 in the first place.

When the warm season arrives, pests wake up from hibernation and start to become active all at once, but you may not notice this right away, and various pest damages may occur within your space without you realizing it.

The present invention was made in consideration of these points, and its purpose is to provide a method for effectively controlling pests in spaces into which the pests may enter to overwinter.

In order to achieve the above object, a first aspect of the present disclosure can be premised on a pest control method for controlling pests in a space. A holding means for holding a transpiration-type pest control agent is prepared in a space where the room temperature rises from below the hibernation onset temperature at which the pests to be controlled start hibernation to above the activity onset temperature at which the hibernating pests start to become active, when the room temperature is below the hibernation onset temperature. Thereafter, the amount of the pest control agent transpire from the holding means into the space is increased as the room temperature rises, and pests that have started to become active when the room temperature reaches or exceeds the activity onset temperature are controlled.

That is, when the room temperature of the space is low and is below the hibernation start temperature, the pests are, for example, deep inside gaps and are less active, so even if a pest control agent is sprayed into the space, the effect is low. In this regard, according to the present disclosure, when the room temperature of the space rises and the pests start to become active and crawl out of gaps, the amount of transpired pest control agent from the holding means increases, and the concentration of the pest control agent in the air in the space increases. In other words, the timing at which the hibernating pests start to become active can be synchronized with the timing at which the amount of transpired pest control agent is increased. This makes it possible to effectively control the pests when they start to become active in the space. In addition, when the room temperature of the space is low, the amount of transpired pest control agent from the holding means is smaller than when the room temperature is high, so that it is possible to reduce the unnecessary transpired pest control agent in a state where the control effect is low.

In the second aspect of the present disclosure, the pest control agent having a vapor pressure of 1×10 ⁻⁵ to 1×10 ⁻³ mmHg at 30° C. can be held in the holding means.

With this configuration, a pest control agent with a vapor pressure in the above range barely transpires below the hibernation onset temperature, but transpires appropriately when the temperature reaches or near the activity onset temperature, further enhancing the above-mentioned control effect.

In a third aspect of the present disclosure, the pest control agent is at least one of transfluthrin and metofluthrin.

In other words, by holding at least one of transfluthrin and metofluthrin in the holding means, the amount of transpired at temperatures below the hibernation onset temperature is extremely small, preventing unnecessary consumption of the drug, while at the same time, when the temperature reaches or is close to the activity onset temperature, a sufficient amount is transpired, providing high control efficacy.

In a fourth aspect of the present disclosure, the hibernation onset temperature can be 15°C and the activity onset temperature can be 20°C.

In a fifth aspect of the present disclosure, the space may be a non-residential space where no humans reside.

That is, spaces inhabited by people are often kept at a certain temperature or higher even during the winter by heating devices and the like, so pests rarely hibernate in those spaces. However, in spaces where people do not live, such as warehouses, the room temperature drops below the hibernation onset temperature during the winter, causing pests to hibernate, and then when spring arrives the room temperature rises and the pests begin to become active, which can cause pest damage to luggage in the warehouse and the like. The method disclosed herein is particularly suitable because it can be used in such spaces where people do not live, and this makes it possible to effectively control pests that have woken up from hibernation and begun to become active.

In a sixth aspect of the present disclosure, when the temperature is below the hibernation onset temperature, the pest control agent is attached to the floor or the inner surface of the wall of the space, making the floor or wall the retention means, and the amount of the pest control agent evaporating from the inner surface of the floor or wall is increased by increasing the room temperature.

With this configuration, the inner surfaces of the floors and walls that divide the space can be used as the holding means, so there is no need to provide a dedicated holding means to carry out this pest control method, and this pest control method can be carried out easily. Also, because the inner surfaces of the floors and walls have a large surface area, the pest control agent can be efficiently evaporated from a large surface area.

In a seventh aspect of the present disclosure, the pest control agent is stored in an aerosol container, and the pest control agent is sprayed from the aerosol container toward the floor or the inner surface of the wall of the space, thereby adhering to the floor or the inner surface of the wall.

This configuration allows the pest control agent to be easily applied over a wide area of the inner surface of the floor or wall.

In an eighth aspect of the present disclosure, when the room temperature within the space and the temperature outside the space are below the hibernation initiation temperature at which the pests to be controlled begin hibernation, an impregnated body impregnated with the pest control agent is placed so that it is exposed to outside air taken in through an outside air intake hole provided in a wall that divides the space. Thereafter, the amount of the pest control agent transpire from the impregnated body into the space is increased by taking in outside air through the outside air intake hole and increasing the temperature outside the space, and the room temperature reaches or exceeds the activity initiation temperature of the hibernating pests, thereby controlling the pests that have begun to become active.

That is, the temperature of the outside air taken in through the outside air intake hole may fluctuate, for example, with the change of seasons, and may rise from below the hibernation start temperature to above the activity start temperature. As the temperature of the outside air taken in through the outside air intake hole increases, the amount of pest control agent that evaporates from the impregnated body increases compared to when the temperature is low. Also, when the temperature of the outside air rises above the activity start temperature, the room temperature in the space also rises above the activity start temperature, increasing the activity of the pests. In other words, the timing at which hibernating pests start to become active can be coordinated with the timing at which the amount of evaporation of the pest control agent is increased, so that when hibernating pests in the space start to become active, the pests can be effectively controlled.

As explained above, the amount of pest control agent that evaporates into the space can be increased as the room temperature rises, making it possible to effectively control pests in spaces where they may enter to overwinter.

1 is a perspective view of a warehouse in which pests are controlled by a pest control method according to a first embodiment of the present invention. FIG. 1 is a graph showing the relationship between the amount of evaporation of a pest control agent and room temperature. 1 is a graph showing the mortality rate of pests when metofluthrin is used. 1 is a graph showing the mortality rate of pests when transfluthrin is used. FIG. 5 is a cross-sectional view of a warehouse in which pests are controlled by a pest control method according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view of a warehouse in which pests are controlled by a pest control method according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view of a house in which pests are controlled by a pest control method according to a fourth embodiment of the present invention. FIG. 11 is a perspective view of a loading platform of a truck that controls pests using a pest control method according to a fifth embodiment of the present invention.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its applications, or its uses.

(Embodiment 1)
FIG. 1 shows a warehouse 1 in which pests are controlled by a pest control method according to embodiment 1 of the present invention. In embodiment 1, a case in which pests in a space R of the warehouse 1 are controlled by the pest control method will be described. The warehouse 1 is composed of, for example, a floor 2, a side wall 3, and a roof 4. The floor 2 may be made of, for example, concrete, wood, or steel plate, and the material does not matter. The side wall 3 is disposed so as to surround the floor 2 and extends upward. The material of the side wall 3 also does not matter. The roof 4 is installed on the upper part of the side wall 3. The roof 4 may be a ceiling. The floor 2, the side wall 3, and the roof 4 define a space R. The space R according to embodiment 1 is a non-residential space where no one lives, and no heating appliances are installed.

The size, volume, shape, etc. of the warehouse 1 can be set as desired. The warehouse 1 may be fixed to the ground, or may be movable and installed, for example, on a railway vehicle, automobile, aircraft, ship, etc. A movable warehouse 1 may be called, for example, a loading platform, a cargo room, a loading room, etc. In any case, it has a space R.

The room temperature (air temperature in space R) in warehouse 1 fluctuates, for example, due to changes in the outside air temperature and the intensity of solar radiation. The outside air temperature and solar radiation may change depending on the season. For example, the room temperature in space R may be below 15°C during winter and above 20°C from spring to autumn. If warehouse 1 is fixed, the room temperature in space R may rise from below 15°C to above 20°C due to seasonal changes. Note that the room temperature in space R of warehouse 1 may fluctuate during the day due to daily fluctuations in the outside air temperature, but it is unlikely that hibernating pests will start to become active due to such short-term temperature fluctuations alone. Therefore, in the present invention, it may be appropriate to consider the "room temperature" as the average room temperature over a certain period of time. For example, the average room temperature over a day in space R of warehouse 1 may be taken as the "room temperature".

In addition, the outside temperature and solar radiation can vary depending on the region, and the further away from the equator, that is, the closer to the North Pole and South Pole, the lower the outside temperature and the weaker the solar radiation. Therefore, even if the season does not change, if warehouse 1 is mobile, the room temperature in space R can rise from below 15°C to above 20°C by moving from a high latitude region to a low latitude region.

Item 5 is stored in space R of warehouse 1. Item 5 is a tangible object other than real estate, and is not limited to, but may be, for example, daily necessities, medicines, electrical appliances, books, food, beverages, etc. These are usually stored in warehouse 1 in a packaged state in cardboard boxes or the like. However, if item 5 is, for example, furniture, building materials, automobiles, motorcycles, bicycles, etc., it may be stored in warehouse 1 as is (exposed) without any special packaging. Note that item 5 does not have to be stored in space R.

Warehouse 1 has openings such as entrances and exits for people to enter and exit, and ventilation holes (not shown), through which pests outside warehouse 1 can invade space R. Also, when item 5 is brought into the warehouse, pests attached to item 5 can be brought into space R. This can occur, for example, when item 5 is furniture or the like and pests get into gaps or internal cavities in the furniture while it is temporarily stored outside in an unpackaged (exposed) state.

The pest control method is a method for controlling pests that have been brought into or invaded the space R as described above. Control means preventing damage caused by pests and exterminating pests to prevent damage in advance, including killing the pests. Here, damage caused by pests includes damage to the item 5, such as the item 5 being soiled or bitten by the pest. It also includes damage to people, such as a person who enters the space R being bitten by the pest or a person who sees the pests active in the space R feeling uncomfortable. It also includes pests that start to be active in the space R advancing outside the warehouse 1 and causing infectious diseases or agricultural damage to the surrounding area. Therefore, damage caused by pests does not necessarily occur only within the space R. Note that if it is necessary to prevent only pest damage within the space R, it is not necessary to kill the pests, and they may be exterminated by, for example, driving them out of the space R. However, pests are less active during hibernation, so they do not actually cause damage during that period. In this regard, the present invention controls pests when they wake up from hibernation and start to become active, which makes it possible to effectively prevent damage caused by pests.

Pests to be controlled by the pest control method are hibernating pests, such as Culex pipiens, flies, moths such as Lymantria dispar and Pyralidae, and stink bugs such as Brown stink bugs, German winged green bugs, and Round stink bugs. Most of these pests begin hibernation when the temperature falls below 15°C, so 15°C is the hibernation start temperature. The hibernation start temperature may be changed depending on the pest to be controlled, and can be set, for example, in the range of 12°C to 15°C. Most hibernating pests begin to become active at temperatures above 20°C, so 20°C is the activity start temperature. The activity start temperature may be changed depending on the pest to be controlled, and can be set, for example, in the range of 20°C to 25°C. In other words, the room temperature in space R of warehouse 1 can rise from below the hibernation onset temperature of pests to above the activity onset temperature at which hibernating pests start to become active due to seasonal changes or long-distance migration. Conversely, it can also fall from above the activity onset temperature to below the hibernation onset temperature.

In the pest control method, a pest control agent having transpiration properties is used. Here, "having transpiration properties" means that the pest control agent is solid or liquid at normal temperature and pressure and has a vapor pressure that allows it to transpire gradually. A pest control agent having a vapor pressure of 1×10 ^-5 to 1×10 ^-3 mmHg at 30° C. is suitable for this control method. As the pest control agent, a known insecticide can be used, and a fragrance having a repellent effect can also be used. Specific examples of the pest control agent include pyrethroid compounds such as transfluthrin, metofluthrin, empentrin, and profluthrin, and among these, transfluthrin or metofluthrin is preferred. Only one of the pest control agents may be used, or two or more of them may be used in combination or in combination.

The pest control method includes a preparation process and a chemical vaporization process as multiple steps. In the preparation process, a holding means for holding the pest control agent is prepared in the space R of the warehouse 1 when the room temperature in the space R is equal to or lower than the hibernation starting temperature. Examples of the holding means include the inner surface of the floor 2 or the side wall 3. Examples of methods for holding the pest control agent in the holding means include, but are not limited to, a method of attaching a chemical solution containing the pest control agent to the inner surface of the floor 2 or the side wall 3 by spraying using an aerosol container or a pump sprayer, applying using a brush or roller, or scattering using a shower container.

As an example, the case where an aerosol container 6 is used will be described. The aerosol container 6 contains a pesticide, a solvent for dissolving the pesticide, and a propellant for spraying the pesticide and the solvent. Examples of propellants include liquefied petroleum gas (LPG) and dimethyl ether (DME), and any one of these may be used alone or in combination. The propellant may contain nitrogen gas or carbon dioxide gas. In addition, the aerosol container 6 may contain a spreading agent, a volatilization regulator, a synergist, and the like, as necessary, which allows the efficacy and duration of the pesticide to be adjusted. The aerosol container 6 containing the pesticide may also be called an aerosol product.

The aerosol container 6 is provided with, for example, a spray nozzle and a spray button (not shown). The user holds the aerosol container 6 in his/her hand and presses the spray button to spray the pest control agent from the spray nozzle. In the preparation process, when the temperature is equal to or lower than the hibernation start temperature, the pest control agent can be sprayed from the aerosol container 6 toward the inner surface of the floor 2 or the side wall 3 of the space R, thereby attaching the pest control agent to the inner surface of the floor 2 or the side wall 3. In this case, the inner surface of the floor 2 or the side wall 3 to which the pest control agent is attached becomes the holding means. The pest control agent may be attached to both the inner surfaces of the floor 2 and the side wall 3, or may be attached only to the floor 2, or may be attached only to the inner surface of the side wall 3. The pest control agent may be attached to the entire surface of the floor 2 or only to a part of it. Similarly, the pest control agent may be attached to the entire surface of the inner surface of the side wall 3, or may be attached only to a part of it. The pest control agent may also be attached to the ceiling of the roof 4. In this case, the ceiling serves as the retaining means.

The holding means prepared in the preparation process may also be a member that is not fixed to the space R, such as a cloth material or a plate material. In this case, the cloth material or plate material holding the pest control agent can be placed anywhere in the space R. In this case, the work of attaching the pest control agent to the holding means (cloth material, plate material, etc.) does not necessarily have to be performed inside the space R, and the pest control agent may be attached to the holding means outside the space R, and then the holding means may be brought into the warehouse R. In this way, the holding means holding the pest control agent can be prepared by bringing the holding means from outside into the warehouse R.

The preparation process may be carried out before the item 5 is brought into the warehouse 1, after the item 5 is brought into the warehouse 1, or in parallel with the bringing in of the item 5. However, when the pest control agent is attached to the holding means by spraying, applying, scattering, etc. in the warehouse 1, if there is an item 5 nearby, the pest control agent may adhere to the item 5 and cause stains or dirt. From the viewpoint of avoiding this, it is preferable to carry out the preparation process before the item 5 is brought into the warehouse 1.

From the viewpoint of efficiently evaporating the pest control agent into the space R in the chemical evaporation process described later, it is preferable that the holding means for attaching the pest control agent in the preparation process is exposed to the space R in the chemical evaporation process. For example, if an item 5 is placed on the floor 2 after the pest control agent is attached to the floor 2, the part of the floor 2 that the item 5 touches is not exposed to the space R, so the pest control agent attached to that part cannot evaporate efficiently. Therefore, when the preparation process is performed before the item 5 is brought into the warehouse 1, it is preferable not to attach the pest control agent to the part of the floor 2 or the side wall 3 that the item 5 touches, and it is preferable to attach the pest control agent only to the part that does not come into contact. It is preferable that there is a gap of several centimeters between the item 5 and the floor 2 or the side wall 3 that holds the pest control agent, and there is no problem with the evaporation of the pest control agent.

After the preparation process, the chemical transpiration process is carried out. That is, when the pest control agent is held in the holding means in the preparation process, the room temperature in space R is low, below the hibernation onset temperature, so the pest control agent held in the holding means hardly transpires. Thereafter, the room temperature in space R gradually rises due to seasonal changes and the movement of warehouse 1. The rise in room temperature in space R raises the temperature of the pest control agent held in the holding means, thereby increasing the amount of pest control agent transpire from the holding means into space R.

The effects of the pest control methods described above are as follows:

That is, when the room temperature in space R is below the hibernation onset temperature, pests hibernate, for example, by burrowing into gaps between items 5 or into grooves and cracks in the sidewall 3. It is difficult to find pests in this state, so it is not realistic to exterminate them one by one. Furthermore, even if space R is treated with a pest control agent that evaporates at this room temperature, the pests are unable to be effectively controlled because they are deep in the gaps and their activity has decreased, and the evaporated pest control agent will be wasted.

In this regard, according to this embodiment, when the room temperature of the space R is low, the amount of pest control agent that evaporates from the holding means is less than when the room temperature is high. Therefore, when the control effect is low (when the pests are hibernating), the amount of pest control agent that evaporates into the space R is small, and waste of the pest control agent is suppressed.

When the room temperature in space R rises above the activity start temperature, the hibernating pests start to become active and crawl out from the depths of gaps, etc. Furthermore, when the room temperature in space R rises, the amount of pest control agent evaporating from the holding means increases, and the concentration of the pest control agent in the air in space R increases. In other words, the timing at which the hibernating pests start to become active can be synchronized with the timing at which the amount of evaporation of the pest control agent is increased. This makes it possible to increase the concentration of the pest control agent in the air of space R when the pests hibernating in space R crawl out into space R, thereby effectively controlling the pests.

Next, the relationship between the amount of evaporation of the pesticide and the temperature will be explained based on the graph shown in Figure 2. This graph shows how the amount of evaporation of the pesticides Metofluthrin and Transfluthrin changes with temperature. The horizontal axis of the graph is room temperature (℃), which is almost the same as the temperature of Metofluthrin and Transfluthrin. The vertical axis of the graph is the evaporation amount ratio, which shows the ratio when the room temperature is 25℃ is set to 1. If the evaporation amount ratio is "2", for example, it means that twice the amount of evaporation at the room temperature of 25℃ is evaporated. The amount of evaporation was measured at room temperatures of 35℃, 30℃, 27℃, 25℃, and 22℃. The measurement method was to impregnate a nonwoven fabric with a predetermined amount of pesticide and blow air with a fan, suck the air that passed through the nonwoven fabric downstream of the nonwoven fabric, capture the pesticide contained in the air with silica gel, and measure the amount of the captured pesticide.

As can be seen from Figure 2, the transpiration rate of both Metofluthrin and Transfluthrin increases as the room temperature increases, and conversely, decreases as the room temperature decreases. The temperature at which the transpiration rate of Metofluthrin becomes zero is 18.8°C, calculated by linear approximation, which is below the activity onset temperature mentioned above. The temperature at which the transpiration rate of Transfluthrin becomes zero is 13.6°C, calculated by linear approximation, which is below the hibernation onset temperature mentioned above, but below the hibernation onset temperature, almost no transfluthrin transpires.

As described above, metofluthrin and transfluthrin have appropriate transpiration properties at temperatures above the temperature at which pests are active, and barely transpire below temperatures at which pests are inactive, particularly below the temperature at which hibernation begins, making them suitable as pest control agents for use in the pest control method described above. Note that since the lower the temperature, the lower the transpiration property, and the higher the temperature, this is a general property of substances that have transpiration properties, any pest control agent that has a vapor pressure similar to that of metofluthrin or transfluthrin can be used in the pest control method of the present invention.

(Pest control test)
Next, a test for determining the amount of pesticide required to actually control pests will be described. Male and female brown marmorated stink bugs were prepared as test insects (pests to be controlled). Stink bugs are known to be highly resistant to pesticides (especially pyrethroid-based agents), so if a control effect is exerted against stink bugs, a sufficiently high control effect can be expected against other pests such as mosquitoes, flies, and moths.

The test room is a windless, temperature-controlled room of about 8 tatami mats (33 m ³ ). The test insects were placed in a plastic cup and covered with a 16-mesh nylon net. The plastic cups containing the test insects were placed on the four corners of the floor of the test room. A fan-type transpiration device for transpiration of the pest control agent (Metofluthrin) was installed in the center of the floor of the test room. The room temperature during the test was 25°C, and the test room was sealed without ventilation during the test. During the test, the test insects were fed soybeans and water as food, and the condition of the test insects was observed until one week had passed from the start of the test. The amount of transpiration of Metofluthrin was 2.5 mg per hour (Test Example 1) and 5.0 mg per hour (Test Example 2).

As shown in Figure 3, after 4 days from the start of the test, the mortality rate exceeded 50% in both Test Examples 1 and 2, demonstrating that the control effect of Metofluthrin is sufficiently high. In particular, it can be seen that after 7 days with an evaporation rate of 5.0 mg/hr (Test Example 2), the mortality rate can be increased to 100%.

Based on the above, the minimum amount of Metofluthrin required to eliminate stink bugs 100% is:
5.0mg/hr × 168hr (7 days) / 33m ³ = 25mg/m ³
It is estimated that. Therefore, if the volume of the space R in which the pest control method is used is known, the minimum amount of Metofluthrin required to eliminate 100% of stink bugs can be calculated. Then, by holding that amount or more of Metofluthrin in a holding means and placing it in the space R, when the room temperature of the space R reaches or exceeds the activity start temperature and the hibernating stink bugs start to become active, the stink bugs can be eliminated. Note that when the aim is not to eliminate 100% of stink bugs, for example when it is sufficient to simply drive the stink bugs out of the space R, the amount of Metofluthrin can be reduced from the above amount.

If another pest control agent is used instead of metofluthrin, or if multiple pest control agents are used in combination, the minimum amount of drug required to control stink bugs within space R can be calculated by conducting similar tests.

Next, we will explain the test that was conducted to confirm the stink bug control effect using an aerosol container 6 containing transfluthrin as a pest control agent and using the floor of the test room as a holding means.

The test room and test insects were the same as those in the case of using the above-mentioned evaporation device. In addition, since transfluthrin has a vapor pressure about twice that of metofluthrin, it is expected that stink bugs can be exterminated 100% if there is about twice the amount of transfluthrin (50 mg/m ³ ) of metofluthrin, taking into consideration that it evaporates and is consumed early. Therefore, the required amount of transfluthrin (50 mg/m ³ × 33 ^{m 3} = 1.65 g) expected from the volume of the test room (33 m ³ ) was placed in an aerosol container 6. The entire content of this aerosol container 6 was sprayed onto the floor surface of the test room to attach it. Then, the test insects placed in a plastic cup covered with a 16-mesh nylon net were placed in the test room. The room temperature during the test was 25° C., and the ventilation conditions were set to be no ventilation and six ventilations per hour.

The mortality rates of the test insects were calculated on the day the test started, and four and six days after the start of the test, and the results are shown in the graph in Figure 4. In other words, without ventilation, the mortality rate was 100% on the day the test started, and with ventilation six times per hour, the mortality rate was 90% on the day the test started. In this way, it can be seen that by retaining the calculated required amount of pest control agent (transfluthrin in this case) in the retention means (the floor in this case), a sufficient control effect against stink bugs active in the space can be obtained. Note that, since the effect decreases when ventilation is performed, it is preferable to increase the amount of pest control agent retained in the retention means beyond the amount mentioned above depending on the ventilation conditions.

As mentioned above, stink bugs are pests that are resistant to pesticides, so if a pesticide is effective against stink bugs, it will be sufficiently effective against mosquitoes, flies, moths, etc. For example, research by the present inventors has shown that a pesticide that is about 1/170 the strength of the pesticide required for stink bugs is effective against house mosquitoes, about 1/19 the strength of the pesticide required for stink bugs is effective against flies, and about 1/4.5 the strength of the pesticide required for stink bugs and gypsy moths is effective against stink bugs. Therefore, if stink bugs are not the target and only relatively weak pests such as mosquitoes, flies, or moths are the target, the amount of pesticide can be reduced accordingly.

(Embodiment 2)
5 is a cross-sectional view of a warehouse 1 in which pests are controlled by a pest control method according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the pest control agent is diffused into the space R by utilizing the outside air taken in from the outside. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanations are omitted, and the different parts are explained in detail.

An outside air intake duct 11 is provided on the side wall 3 of the warehouse 1. The outside air intake duct 10 is installed so as to penetrate the side wall 3 in the thickness direction. An outside air intake hole 10a is formed in the outside air intake duct 10 to take in air outside the warehouse 1 (outside air) into the warehouse 1. The upstream end opening of the outside air intake hole 10a opens to face the outside of the warehouse 1, while the downstream end opening of the outside air intake hole 10a opens to face the inside of the warehouse 1. A fan 11 and a motor 12 that drives the fan 11 are arranged in the outside air intake duct 10. A power circuit (not shown) is connected to the motor 12, so that the motor 12 can be started and stopped at the desired timing and can rotate the motor 12 at the desired rotation speed. Although not shown, the warehouse 1 is also provided with an exhaust port, which is opened appropriately when introducing outside air so that the introduction of outside air is not hindered. The pest control agent can be impregnated into the impregnated body 13 in anticipation of the amount of pest control agent that will be discharged from the exhaust port.

An impregnated body 13 impregnated with the pest control agent used in embodiment 1 is disposed downstream in the outside air intake hole 10a. The impregnated body 13 can be made of a breathable material such as nonwoven fabric, foam material, mesh material, etc., and may be flat or pleated. By disposing the impregnated body 13 downstream in the outside air intake hole 10a, the impregnated body 13 can be installed so that it is exposed to the outside air taken in from the outside air intake hole 10a. Either the fan 11 or the impregnated body 13 may be disposed upstream in the air flow direction, and the impregnated body 13 may be disposed upstream of the fan 11 in the air flow direction.

The impregnated body 13 can be replaced with a new one. For example, the impregnated body 13 is incorporated into a chemical cartridge, and when the amount of impregnated pest control agent becomes low, the old chemical cartridge is replaced with a new chemical cartridge. The amount of impregnated pest control agent can be estimated based on the operating time of the fan 11.

In the preparation process of embodiment 2, when the room temperature inside space R and the air temperature outside space R are below the hibernation onset temperature, the impregnated body 13 impregnated with the pest control agent is placed so that it is exposed to outside air taken in through the outside air intake hole 10a. Because the room temperature inside space R is below the hibernation onset temperature, the pests in space R are in a hibernation state. Also, because the air temperature outside space R is below the hibernation onset temperature, the room temperature inside space R remains below the hibernation onset temperature even if outside air is introduced through the outside air intake hole 10a. Also, because the outside air below the hibernation onset temperature hits the impregnated body 13, very little of the pest control agent transpires.

In the subsequent chemical evaporation process, outside air is introduced from the outside air intake hole 10a. When the temperature outside the space R rises due to seasonal changes or the movement of the warehouse 1, outside air at or above the activity start temperature hits the impregnated body 13. This causes the temperature of the pest control agent impregnated in the impregnated body 13 to be equal to or higher than the activity start temperature, so the amount of the pest control agent evaporated from the impregnated body 13 into the space R can be increased. In addition, by introducing outside air at or above the activity start temperature, the room temperature in the space R becomes equal to or higher than the activity start temperature, and the pests start to become active. Therefore, in the case of embodiment 2 as well, the timing at which the hibernating pests start to become active can be matched with the timing at which the amount of evaporation of the pest control agent is increased, so that when the pests hibernating in the space R start to become active, the pests can be effectively controlled.

In addition, the introduction of outside air from the outside air intake hole 10a may be performed all the time, or may be performed only during the chemical transpiration process. When the introduction of outside air from the outside air intake hole 10a is performed all the time (i.e., when the fan 11 is always driven even during winter), the impregnated body 13 is always exposed to airflow, so there is a possibility that the pest control agent will transpire slightly from the impregnated body 13 even during winter. Even in this case, if the outside air is below the hibernation start temperature, the amount of transpired pest control agent is suppressed, so that the pest control agent can be prevented from transpiration in vain. However, in terms of further suppressing the pest control agent from transpiration in vain, it is preferable to introduce outside air only during the chemical transpiration process (i.e., not to drive the fan 11 during winter). A plurality of outside air intake holes 10a and impregnated bodies 13 may be provided in one warehouse 1. The outside air intake holes 10a and impregnated bodies 13 may be provided on the ceiling. The holding means of embodiment 1 and the impregnated body 13 of embodiment 2 may also be used in combination.

(Embodiment 3)
6 is a cross-sectional view of a warehouse 1 in which pests are controlled by a pest control method according to a third embodiment of the present invention. The second embodiment differs from the first embodiment in that a heating device 20 is installed. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanations are omitted, and the different parts are explained in detail.

The warehouse 1 is equipped with a heating device 20 for heating the air in the space R. The heating device 20 may be, for example, a stove, an electric heater, a heat pump air conditioner, etc., and the type is not particularly limited. The heating device 20 may also be installed outside the warehouse 1, in which case a duct can be provided to introduce the warm air sent from the heating device 20 into the space R. When the heating device 20 is turned off in winter, the room temperature in the space R is below the hibernation start temperature. At this time, a preparation process is carried out, and the pest control agent is retained, for example, on the inner surface of the floor 2 or the side wall portion 3.

Since no one lives in the warehouse 1, the heating device 20 is usually kept off. Therefore, almost no pest control agent evaporates until the season changes to spring. However, if it is discovered that there is a high possibility that pests have entered the warehouse 1 and are hibernating, or if it becomes necessary to exterminate pests during the winter for some reason, the heating device 20 is operated to forcibly raise the temperature inside the warehouse 1 to a temperature higher than the temperature at which the pests start to become active. This makes it possible to make the pests crawl out and increase the amount of evaporation of the pest control agent to control the pests. Therefore, in the case of embodiment 3, the timing at which the hibernating pests start to become active can be matched with the timing at which the amount of evaporation of the pest control agent is increased, so that when the pests hibernating in the space R start to become active, the pests can be effectively controlled. In addition to the heating device 20 of embodiment 3, the impregnated body 13 of embodiment 2 may be installed.

(Embodiment 4)
7 is a cross-sectional view of a house 30 in which pests are controlled by a pest control method according to a fourth embodiment of the present invention. The fourth embodiment differs from the first embodiment in that the present invention is applied to a house 30 in which people live. The differences from the first embodiment will be described in detail below.

The house 30 is, for example, a villa or the like that is not occupied during the winter and is occupied only from spring to autumn. The house 30 has a floor 32, side walls 33, and a roof 34 that divide the interior space R1. Furniture 35A, electrical appliances 35B, and the like are placed in the interior space R1, and pests may get into the gaps or inside these items and hibernate, but they do not come out during the winter.

In the fourth embodiment, at the beginning of winter, the pest control agent stored in the aerosol container 6 is applied to the floor 32, the inner surface of the side wall 33, etc. As the season changes to spring and the outside temperature rises, the pests start to become active when the temperature in the indoor space R1 exceeds the activity start temperature. When the pests start to become active, the amount of evaporation of the pest control agent increases, and the pests can be controlled. Therefore, when the warm season arrives and people move into the house 30, the pests have already been controlled, and damage caused by pests can be prevented.

(Embodiment 5)
Fig. 8 is a perspective view of a truck bed 40 for controlling pests by a pest control method according to a fifth embodiment of the present invention. The fifth embodiment differs from the first embodiment in that the present invention is applied to the truck bed 40. The differences from the first embodiment will be described in detail below. The vehicle body is omitted in Fig. 8.

Figure 8 is a perspective view of the bed 40 of a truck seen from the rear of the vehicle; this truck is a long-distance truck. The bed 40 is provided with a cargo compartment (space) R2 defined by a floor 42, a side wall portion 43, and an upper wall portion 44. The cargo compartment R2 can be opened and closed by a door 46. Note that the present invention can also be applied to a cargo compartment of a container in a freight train or a long-distance transport ship, instead of a long-distance truck.

For example, a long-distance truck travels from a cold region where the outside temperature is below 15°C (hibernation start temperature) to a warm region where the outside temperature is above 20°C (activity start temperature). The temperature inside the cargo compartment R2 of such a long-distance truck changes in the same way as the outside temperature, rising from below the hibernation start temperature to above the activity start temperature. When the temperature inside the cargo compartment R2 is below the hibernation start temperature, a pest control agent is held on the floor 42, the inner surface of the side wall portion 43, the inner surface of the upper wall portion 44, etc. of the cargo compartment R2. There is a risk that pests are hibernating inside the cargo compartment R2 when the temperature is below the hibernation start temperature, but when the truck travels to a warm region, the pests crawl out and the amount of evaporation of the pest control agent increases, allowing the pests to be controlled, thereby preventing pest damage to luggage, etc.

In addition, in the fifth embodiment, an outside air intake hole 49 may be provided as in the second embodiment, and an impregnated body 48 impregnated with a pest control agent may be installed. In this case, when the room temperature inside the cargo room R2 and the air temperature outside the cargo room R2 are below the hibernation start temperature, the impregnated body 48 is installed so that it is exposed to outside air taken in through the outside air intake hole 49 provided in the side wall portion 43.

After that, outside air is taken in through the outside air intake hole 49, and the amount of pest control agent that evaporates from the impregnated body 48 into the cargo compartment R2 is increased by increasing the temperature outside the cargo compartment R2. When the room temperature R2 reaches or exceeds the activity temperature of the pests, the pests that have started to become active can be controlled.

The above-described embodiment is merely illustrative in all respects and should not be interpreted as limiting. Furthermore, all modifications and changes within the scope of the claims are within the scope of the present invention. For example, the present invention can be applied to attics, stores that are not used during the winter, garages, etc.

As described above, the pest control method of the present invention can be used, for example, in spaces into which pests may enter to hibernate during the winter.

1 Warehouse 2 Floor (holding means)
3 Side wall part (holding means)
6 Aerosol container 10a Outside air introduction hole 13 Impregnated body R Space

Claims (6)

A pest control method for controlling pests in a space, comprising:
a holding means for holding a pest control agent having a vapor pressure of 1×10 -5 to 1× ^{10 -3} mmHg at 30° C. is prepared in the space where the room temperature rises from below the hibernation onset temperature at which the pests to be controlled start hibernation to above the activity onset temperature at which the hibernating pests start to become active, when the room temperature is below the hibernation onset temperature;
Thereafter, the amount of the pest control agent evaporated from the holding means into the space is increased by increasing the room temperature, and the pests that have begun to become active when the room temperature reaches or exceeds the activity initiation temperature are controlled in this pest control method. The method for controlling pests according to claim 1,
The pest control method, wherein the pest control agent is at least one of transfluthrin and metofluthrin. The method for controlling pests according to claim 1 or 2 ,
The hibernation onset temperature is 15° C.,
The pest control method, wherein the activity initiation temperature is 20°C. The method for controlling pests according to any one of claims 1 to 3 ,
The pest control method, wherein the space is a non-residential space where no humans reside. A pest control method for controlling pests in a space, comprising:
A pest control agent having transpiration properties is attached to the inner surface of a floor or wall of the space where the room temperature rises from below the hibernation onset temperature at which the pests to be controlled start hibernation to above the activity onset temperature at which the hibernating pests start to become active, and the floor or wall serves as a holding means for the pest control agent, and the holding means with the pest control agent attached thereto is prepared when the room temperature is below the hibernation onset temperature,
Thereafter, the amount of the pest control agent evaporated from the holding means into the space is increased by increasing the room temperature, and the pests that have begun to become active when the room temperature reaches or exceeds the activity initiation temperature are controlled in this pest control method. The method for controlling pests according to claim 5 ,
The pest control agent is contained in an aerosol container,
The pest control method comprises spraying the pest control agent from the aerosol container toward the floor or the inner surface of the wall of the space, thereby adhering the pest control agent to the floor or the inner surface of the wall.

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