JP7808328B2 - Apparatus for breeding natural enemy insects, method for breeding natural enemy insects, and method for controlling difficult-to-control microscopic pests - Google Patents

Description

The present invention relates to a breeding device for natural enemy insects, a breeding method for natural enemy insects using said device, and a method for controlling difficult-to-control micro-pest insects. Specifically, the present invention relates to a breeding device for natural enemy insects that can maintain the breeding of phytoseiid mites, which are natural enemy insects, for a longer period of time than conventional devices and increase the number of phytoseiid mites released. Furthermore, in a preferred embodiment of the present invention, the present invention relates to a useful technology that advances the practical application of integrated pest management (IPM), which enables effective control of pests using natural enemy insects both above and below ground in plants, something that has not been done before. In particular, the present invention relates to a technology that uses phytoseiid mites of the Phytoseiidae family belonging to the suborder Gamagomata, exemplified by Phytoseiulus swirskii, as natural enemy insects, and a useful technology that enables the use of Gamagomata of the Gamagomata family in the same device, if necessary.

Difficult-to-control micro-pests (hereinafter referred to as micro-pests or pests) such as thrips, spider mites, and whiteflies are important pests that cause damage to many greenhouse horticultural crops (hereinafter referred to as greenhouse vegetables or crops) and must be controlled. Micro-pests are difficult to control with chemical pesticides, and biological control using natural enemy insects such as phytoseiid mites has been practiced both domestically and internationally. Considering food safety and the impact on producers' health, biological control centered on the use of natural enemy insects instead of pesticides has attracted attention as IPM (integrated pest management). IPM is a pest management method that uses polyphagous phytoseiid mites such as Phytoseiulus californicus, Phytoseiulus swirskii, and Phytoseiulus cucumeris as natural enemies to control plant pests. These mites feed on the target pests, such as spider mites and thrips.

However, phytoseiid mites are susceptible to changes in the cultivation environment, such as drought and the spraying of chemicals, and to achieve stable pest control effects, it is necessary to release large numbers of natural enemy insects over long periods of time. Known methods for use in this case include "packed formulations," in which natural enemy insects are contained in bags, and "bottle formulations," in which natural enemy insects are contained in bottles. Conventional bottled and packed formulations are unable to adequately mitigate the effects of environmental changes, and therefore, there has been an issue with the inconsistent effectiveness of using natural enemy insects when cultivating greenhouse crops in Japan.

Polyphagous phytoseiid mites, which can be used as natural enemies, are known to multiply when so-called prey mites are provided as an alternative food source when the above-mentioned pest insects that serve as their natural food source are absent or in limited numbers. Taking advantage of this, various breeding devices for natural enemy insects have been proposed as natural enemy support materials. These devices are called Bunker Sheets (registered trademark) and are already in practical use. The applicant of the present application jointly developed this new natural enemy support material (Banker Sheet) and has promoted the spread of IPM using phytoseiid mites as natural enemies, primarily for greenhouse vegetables such as strawberries and cucumbers.

As described in Patent Document 1, a breeding device for natural enemy insects is basically configured as follows: It has a main body with an internal space sealed enough to provide a hiding place for natural enemy insects (shelter from rain, watering, pesticides, etc.), and is equipped with a bag (natural enemy insect storage section) that stores natural enemy insects in an accessible manner, and an egg-laying section where the natural enemy insects can lay eggs. It also describes that the natural enemy insects are stored in the bag in the natural enemy insect storage section, in combination with food such as bait mites necessary for the propagation of the natural enemy insects. As mentioned above, the bag containing the natural enemy insects is called a "pack preparation."

The pack preparation is placed within the internal space of the main body of a breeding device for natural enemy insects, as configured in Patent Document 1, and is used as the "natural enemy insect storage section" of the device, with the aim of more effectively utilizing the natural enemy insects contained within the bag. Of course, the pack preparation can also be used alone as is for releasing natural enemy insects, and is used as such. To enhance convenience in such cases, some pack preparations are equipped with a part for attaching to plants. Widely used pack preparations include, for example, the Miyako Phytoseiulus californicus pack preparation, which contains Miyako Phytoseiulus californicus, a mite that preys on spider mites, in a bag, and the Swirlskii Phytoseiulus swirlskii pack preparation, which contains Phytoseiulus swirlskii, a mite that preys on whiteflies and thrips, in a bag. Both contain one type of natural enemy insect selected from the phytoseiid mites, and the natural enemy insect is selected according to the intended use.

Patent Documents 2 and 3 propose providing a component made of a moisture-slowing, moisture-retaining material in the enclosed space of the main body. They also state that a highly absorbent resin is suitable as the moisture-slowing, moisture-retaining material. They also state that by providing a moisture-slowing, moisture-retaining material that supplies appropriate humidity, the relative humidity within the enclosed space of the main body can be maintained at a high humidity of 70% or more for an extended period of time, and preferably 80% or more. As a result, the enclosure becomes a suitable habitat for natural enemy insects and the prey mites that serve as their food. Therefore, installing a moisture-retaining material is effective in promoting and maintaining their populations. As noted above, Patent Documents 2 and 3 state that the use of a moisture-slowing, moisture-retaining material can maintain a high humidity environment within the enclosed space of the main body that is suitable for the habitat of natural enemy insects and prey mites.

Patent No. 5681334 JP 2018-29591 A Japanese Patent Application Laid-Open No. 2018-29589

In response to the above-mentioned conventional technologies, the inventor believes that the widespread adoption of integrated pest management (IPM) is urgently needed as a means of reducing the use of pesticides, ensuring food safety, and reducing the potential for health damage to agricultural workers, and that it is important to extend this to a wider range of products in the future, rather than limiting it to greenhouse vegetables, as is currently the case. The inventor has recognized that to achieve this, it is necessary to enhance the functionality of natural enemy insect breeding devices (natural enemy support materials) that are already in practical use, particularly to improve the breeding efficiency of natural enemy insects, and in particular to improve the number of insects released from the natural enemy support materials. Specifically, it is necessary to develop technology that allows natural enemy insects to stably breed and live within the natural enemy support material, thereby enabling natural enemy insects to be stably released from the natural enemy support material for a longer period of time, thereby effectively contributing to pest control.

Currently, natural enemy insect breeding devices in practical use are highly water-resistant, have good airtightness and egg-laying sites, and function as shelters for natural enemy insects. They are said to be more durable and can be used for a longer period of time than the aforementioned commercially available pack formulations that are simply attached to plants. In addition to this, if natural enemy insects can be bred stably for a longer period of time than when using conventional devices, and the release conditions for natural enemy insects can be maintained in good condition for a long period of time, it will be possible to reduce the frequency of breeding device replacement, which is advantageous in terms of cost, and it will also be more useful as it will significantly reduce the burden on farmers in installing the device.

The inventor also recognized that while the above-mentioned natural enemy insect propagation device is designed to control above-ground pests whose natural enemy is phytoseiid mites, damage caused by pests such as fungus gnats that feed on underground parts is significant, and that in recent years there has been a desire for the widespread use of IPM (integrated pest management) to control these pests as well. In particular, the inventor believed that if it were possible to improve existing natural enemy insect propagation devices (natural enemy support materials) so that they could simultaneously control pests such as thrips and spider mites that feed on above-ground parts and pests such as fungus gnats that feed on underground parts without making major modifications, the added value of the natural enemy insect propagation devices (natural enemy support materials) could be significantly increased, greatly contributing to the widespread use of IPM (integrated pest management).

Therefore, the first object of the present invention, which has been made in light of the above-mentioned recognition, is to improve a conventional natural enemy insect breeding device (natural enemy support material) with a simple configuration, thereby promoting the proliferation of natural enemy insects, particularly phytoseiid mites, compared to conventional devices (increasing the number released), in order to contribute to the spread of IPM (integrated pest management). The second object is to increase the number of phytoseiid mites released from the natural enemy support material and improve the release period as long as possible, preferably so that phytoseiid mites can be stably propagated over a longer period of time (extending the release period). The ultimate object of the present invention is to develop technology that can provide a useful natural enemy insect breeding device that improves the release of phytoseiid mites, a natural enemy insect, as described above, thereby improving economic efficiency and reducing the workload of farmers.

Furthermore, another object (third object) of the present invention is to improve upon conventional natural enemy insect propagation devices (natural enemy support materials) used for phytoseiid mites with a simple configuration, thereby developing an all-in-one device that can efficiently propagate both phytoseiid mites and other natural enemy insects with biology different from phytoseiid mites, something completely unimaginable with conventional devices, and can be used to control different pests in a wider range of areas, both aboveground where pests are controlled by phytoseiid mites and underground where pests cannot be controlled by phytoseiid mites. The realization of such an all-in-one natural enemy insect propagation device will provide a useful technology that can greatly contribute to the spread of IPM (integrated pest management). Hereinafter, natural enemy insect propagation devices (natural enemy support materials) will sometimes be referred to simply as Bunker Sheet (registered trademark) as a representative example.

The above object can be achieved by the present invention, which provides the following breeding device for natural enemy insects.
[1] A breeding device for natural enemy insects for improving the breeding of natural enemy insects that are natural enemies of difficult-to-control micro-pests, characterized in that the device contains at least the following inside a main body having an enclosed space through which the natural enemy insects can enter and exit: natural enemy insects; bait mites that serve as food for the natural enemy insects; a small pouch-shaped member containing at least food for the bait mites; a felt member for laying eggs; and a moisture-retaining material made of a moisture-slow-releasing water-retaining material; the natural enemy insects are phytoseiid mites of the family Phytoseiidae belonging to the suborder Gamasidae, a representative example of which is Phytoseiidae Swirlskii; the bait mites are at least Caragana mites of the family Caragana mites belonging to the suborder Astigmatidae, a representative example of which is Caragana sugar mite; and the water-retaining material contains bait that has been moistened with an aqueous solution containing sugars.

Preferred embodiments of the above-mentioned natural enemy insect breeding device are as follows.
[2] The bait mites further include a type of acarid mite of the Astigmatidae family belonging to the suborder Acaridae, of which Astigmatism is a representative example, and the device for breeding natural enemy insects described in [1] above is configured so that the initial density of the acarid mite is smaller than the initial density of the sugar mite.
[3] A breeding device for natural enemy insects as described in [2] above, wherein the initial density of the sugar mites is 2 to 40 for an initial density of 1,000.
[4] A breeding device for natural enemy insects described in any one of [1] to [3] above, wherein the sugar is at least one selected from the group consisting of trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol and erythritol.
[5] A breeding device for natural enemy insects described in any of [1] to [4] above, wherein the water-retaining material contains food that has been kept moist using an aqueous solution containing a substance that contains a nitrogen component in addition to the sugars.
[6] The breeding device for natural enemy insects described in [5] above, wherein the substance containing a nitrogen component is at least one selected from the group consisting of urea, peptone, yeasts, amino acids and vitamins.
[7] A breeding device for natural enemy insects described in any of [1] to [6] above, in which the water-retaining material is a granular water-retaining material made of a highly water-absorbent resin, and five pieces are made to retain water so that the total weight is adjusted to 4 to 7 g.
[8] The device for breeding natural enemy insects described in any one of [1] to [7] above, wherein the natural enemy insects further include Gamasid mites of the Gamasidae family belonging to the suborder Gamasida, and the initial density of the Gamasid mites is 1 to 3 per 100 of the one type of phytoseiid mites.

In another embodiment, the present invention provides the following method for propagating phytoseiid mites.
[9] A method for breeding phytoseiid mites to improve the number and duration of release of natural enemy insects, which is used when controlling difficult-to-control micro-pests using natural enemy insects, characterized in that the method is configured to maintain an increase in the population of phytoseiid mites, which are natural enemy insects, for a long period of time using the breeding device for natural enemy insects described in any of [1] to [7] above.

In another embodiment, the present invention provides the following method for propagating phytoseiid mites and Gamasid mites.
[10] A method for propagating phytoseiid mites and Gamas mites, which is used when using natural enemy insects to control difficult-to-control micro-pests, and which involves releasing both natural enemy insects, phytoseiid mites and Gamas mites, characterized in that the method is configured to use the natural enemy insect propagating device described in [8] above to increase the population of phytoseiid mites, and then increase the population of Gamas mites after the proliferation of the phytoseiid mites has weakened.

In addition, the present invention provides, as another embodiment, the following method for controlling difficult-to-control microscopic pests.
[11] A method for controlling difficult-to-control micro-pests, comprising installing the breeding device for natural enemy insects described in any one of [1] to [8] above in an area where the difficult-to-control micro-pests live.

The present invention improves upon conventional natural enemy insect breeding devices (natural enemy support materials) with a simple configuration. First, the use of a water-retaining material containing bait promotes the breeding of natural enemy insects compared to conventional devices. Second, a preferred embodiment of the present invention, which utilizes an improved bait mite configuration, allows breeding to occur stably over a longer period of time, thereby enabling not only an increase in the number of natural enemy insects released but also improvements that extend the release period as long as possible. These breeding and/or breeding extension effects provide a natural enemy insect breeding device that can improve economic efficiency and also contribute to reducing the workload of agricultural workers. Third, the present invention, which utilizes two types of natural enemy insects, improves upon conventional natural enemy insect breeding devices (natural enemy support materials) with a simple configuration, providing an all-in-one natural enemy insect breeding device that can be used to control different pests over a wider area, both above and below ground, using the same device, something that was completely unthinkable with conventional devices. As described above in points 1 to 3, the present invention provides useful technology that can greatly contribute to the spread of IPM (integrated pest management).

1 is a graph showing the effect on the release status of Phytoseiulus swirskii by saccharides and the like introduced into the water-retaining material constituting the breeding device for natural enemy insects of the present invention. 1 is a graph showing the release status of Gamagoma mites (Hypoaspis sp.) when a small number of Gamagoma mites are added in addition to Phytoseiulus swirskii mites to a pack formulation constituting the breeding device for natural enemy insects of the present invention.

The present invention will be described in more detail below, with reference to preferred embodiments. In response to the above-mentioned prior art, the present inventors conducted extensive research into the breeding and release of natural enemy insects in commercially available breeding devices for natural enemy insects, resulting in the present invention. The present inventors conducted extensive research into the breeding conditions of natural enemy insects within the device and the number of natural enemy insects released from the device when using a conventional breeding device for natural enemy insects in practical use. They found that, for example, when using Phytoseiulus swirskii as the natural enemy insect, the number of natural enemy insects released from the device tends not to be maintained as sufficiently over the long term as expected, and that there are cases in which it is difficult to say that the effects of using a breeding device for natural enemy insects are consistently and fully achieved. In response to this situation, the present inventors felt that, since the use of Phytoseiulus swirskii is already in practical use and is being used, there was an urgent need to improve this point. They focused particularly on this point and conducted extensive research, resulting in the present invention.

The present invention makes it possible, through simple means, to significantly improve the proliferation of one species of phytoseiid mite contained in a pack formulation compared to conventional natural enemy insect propagation devices. Moreover, surprisingly, preferred embodiments of the present invention make it possible to maintain this improved proliferation state for a longer period of time, thereby improving the number of natural enemy insects released from the propagation device so that they are sufficiently maintained over a long period of time. Therefore, according to preferred embodiments of the present invention, the improved natural enemy insect propagation device provides a more sustained increase in the number of natural enemy insects released, thereby reducing the number of times the device needs to be replaced, thereby achieving superior benefits such as reduced running costs and reduced labor required for farmers to install the device.

Furthermore, during the above-mentioned investigations, the inventors also noted that conventional natural enemy insect breeding devices and pack formulations all utilize a single type of specific natural enemy insect that feeds on a specific target pest, which is released within a facility to control the pest. They have not considered using multiple types of natural enemy insects in the same device or pack formulation, breeding each of them, and using them to control pests. This is thought to be due to the following reasons. What is important in natural enemy insect breeding devices and pack formulations is to stably breed specific natural enemy insects using bait mites, maintain stable habitat conditions, release the breeding natural enemy insects within a facility, and control the pests by having the specific natural enemy insects prey on the specific pests they prefer. However, having multiple types of natural enemy insects coexist within the same device destabilizes the breeding and habitat conditions of each natural enemy insect, so it was generally considered difficult to release multiple types of natural enemy insects from the same device in conditions favorable for pest control.

In response to this situation, the inventors believed that if it were possible to breed multiple types of natural enemy insects individually within a single breeding device and use it for IPM (integrated pest management), that breeding device would be extremely useful. The inventors then conducted extensive research into this point and discovered that by improving the breeding device for natural enemy insects when using phytoseiid mites as the natural enemy insects discussed above, it is possible to not only steadily breed phytoseiid mites within the same breeding device for the long term, but also breed another natural enemy insect, Gamasida mites, within the same breeding device. These released natural enemy insects prey on the pest insects that they feed on, enabling the control of multiple types of pest insects. This resulted in the development of a natural enemy insect breeding device that provides completely new and unprecedented benefits. With this new natural enemy insect propagation device, the released natural enemy insects, phytoseiid mites, control pests "on leaves and above-ground parts such as flowers, buds, stems and branches," while another natural enemy insect, Gamasid mites, control pests "below-ground parts such as the soil edge and roots." This makes it possible to control pests with natural enemy insects over a wide area with just one propagation device, something that was never possible with conventional natural enemy insect propagation devices or pack formulations.

The present invention was arrived at as a result of detailed studies on the case where the natural enemy insect contained in the pack formulation of a natural enemy insect breeding device (natural enemy support material) is Phytoseiulus swirskii. However, this technology can be similarly applied to other phytoseiid mites. The inventors conducted a comparative study using the Miyako phytoseiid mite, which is a natural enemy insect used in a natural enemy insect breeding device already in practical use, when the pack formulation was used as is, and when the pack formulation was contained in a natural enemy insect breeding device (natural enemy support material). As a result, when Phytoseiulus swirskii was used as the natural enemy insect, as mentioned above, there was a tendency for there to be no significant difference in the number of insects released when comparing using the pack formulation as is and using a natural enemy insect breeding device (natural enemy support material) containing the pack formulation in the conventional manner, whereas when Phytoseiulus californiae was used as the natural enemy insect, using a natural enemy insect breeding device containing Phytoseiulus californiae was clearly more effective than using the pack formulation as is.

In other words, when using Phytoseiulus californiae as the natural enemy insect, it was confirmed that using a natural enemy insect breeding device (natural enemy support material) was more effective than when using Phytoseiulus swirskii as the natural enemy insect, as it consistently achieved effects such as an increase in the number of natural enemy insects released, compared to when using a packed formulation as is. However, even when using Phytoseiulus californiae as the natural enemy insect, it is still necessary to further increase the number of natural enemy insects released and to achieve a longer release period with a single natural enemy support material, just as in the case of Phytoseiulus swirskii examined above.

In contrast, it has been recognized that by simply improving a breeding device for natural enemy insects, such as the configuration specified in the present invention, it is possible to improve the release of Phytoseiulus californicus, a natural enemy insect belonging to the phytoseiid mite genus, compared to conventional devices, just as it does for Phytoseiulus swirskii. Furthermore, the present inventors conducted extensive research and found that the technology specified in the present invention, which breeds two types of natural enemy insects together in the same device and effectively utilizes these two different types of mites to control pests, is applicable to Phytoseiulus californicus, just as it is applicable to Phytoseiulus swirskii.

The first object of the present invention is to provide an effective breeding device (natural enemy support material) for natural enemy insects that can increase the number of phytoseiid mites, a natural enemy insect traditionally used to control above-ground pests, by breeding them in greater numbers and releasing them in greater numbers. The second object of the present invention is to provide a natural enemy support material that can sustain the release of greater numbers of phytoseiid mites over a longer period of time. As described below, the improvements made in this invention involve various modifications to the individual habitats and egg-laying environments of phytoseiid mites and their prey mites. Specifically, first, sugars, which serve as food for phytoseiid mites, are provided in a suitable condition that contributes to their proliferation. Additional measures, such as devising the prey mites to maintain proliferation over a long period of time and maintaining high humidity within the device, are also implemented. Because all of these improvements relate to habitat conditions that are considered common to phytoseiid mites, it is normal for similar effects to be obtained even when using different types of phytoseiid mites. Furthermore, even when achieving the third object of the present invention, which is to combine phytoseiid mites, which control pests above ground, with Gamas mite, a different natural enemy insect that controls pests below ground, and use each natural enemy insect to control completely different pests, the aim is to improve the habitats and egg-laying environments of the phytoseiid mites and Gamas mite, thereby allowing the stable proliferation of both, and it is normal that similar trends and similar effects will be observed even if the types of mites are changed.

In explaining the present invention, the present specification uses Phytoseiulus swirskii as a representative example of phytoseiid mites, which are natural enemy insects. This is because, as previously mentioned, the effectiveness of using a breeding device for natural enemy insects (natural enemy support material), which is believed to function as a shelter for natural enemy insects, is inferior to that of using Phytoseiulus californicus as a natural enemy insect. Therefore, if this can be improved, the present invention will be able to achieve even greater effectiveness. As described above, the technology of the present invention is applicable to phytoseiid mites used as natural enemy insects when controlling above-ground pests. Furthermore, another technology of the present invention makes it possible to breed two types of natural enemy insects in the same device. In this case, the effectiveness of combining phytoseiid mites, which control above-ground pests, with Gambusia mites, which control underground pests, such as at the soil line, has been discovered. By utilizing this different technology, it will be possible to control pests underground, such as at the soil line, in addition to the conventional method of controlling pests above ground using the same propagation device, which is expected to enable pest control over a wide area using natural enemy insects.

The following explains how the present invention was arrived at. First, we will explain the current state of use of conventional natural enemy support materials in Japan and around the world. When used on greenhouse crops, the bottle formulations, pack formulations, and bunker sheets used in the aforementioned conventional technologies function as outlined below, resulting in significantly different natural enemy insect propagation efficiencies. When using bottle formulations, natural enemy insects contained in the bottles are released directly onto the crops along with bran (carrier). As a result, the propagation efficiency of natural enemy insects within the formulations is low. Pack formulations are small pouches containing natural enemy insects, a type of prey mite such as sugar mites, and bran or other food for the prey mite. These pouches are then placed on the crops. With pack formulations, the natural enemy insects that multiply by feeding on the prey mites within the material are gradually released onto the crops. Therefore, compared to bottle formulations, a greater number of natural enemy insects are released, and the release period is longer (up to several weeks).

Bunker Sheet (registered trademark) is a natural enemy support material made from waterproof paper, and is more water-resistant and durable than pack formulations. As explained above, there are various types, including a sealed space inside the material, where the pack formulation and felt, which serves as an egg-laying substrate, are placed, and a type that contains a water-retaining material to regulate humidity within the space as needed. These are placed on crop branches and other areas for use. Bunker Sheets are considered to be particularly effective as shelters that protect natural enemy insects from environmental changes such as temperature and humidity, and it is expected that the period during which natural enemy insects are released will be longer when a Bunker Sheet containing a pack formulation is placed inside a container than when only a pack formulation is used.

In contrast, the inventor's research surprisingly found that when using bunker sheets with Phytoseiulus swirskii as a natural enemy, the number of natural enemy insects released was not significantly different from when only the pack formulation was used. Furthermore, the inventor's detailed research revealed that this tendency was particularly pronounced when the relative humidity of the installation environment was high. That is, when the relative humidity of the installation environment was low, the number of natural enemy insects released was higher when using bunker sheets than when only the pack formulation was used. Furthermore, in the study in which the number of natural enemy insects released was not significantly different from when only the pack formulation was used, the bunker sheets were used with 2-3 g of a water-retaining material, a commonly available accessory for commercially available bunker sheets, soaked in water. Based on these findings, the inventor discovered that if the relative humidity of the installation environment can be maintained at a stable high level, for example, above 90%, it is possible to increase the number of natural enemy insects released even with only the pack formulation. However, maintaining a constant relative humidity of above 90% in the installation environment of a greenhouse or other facility is difficult due to running costs. Therefore, the inventor first came to the conclusion that when using a bunker sheet, it was necessary to increase the humidity inside the bunker sheet. Further research was then conducted, recognizing that in order to achieve the effect of releasing a greater number of natural enemy insects, it was not enough to simply increase the moisture content of the water-retaining material; rather, some ingenuity was needed to achieve a greater effect.

The inventors also conducted research into achieving a new effect completely unimaginable with conventional bunker sheet utilization techniques: breeding two types of natural enemy insects in the same device and releasing them for use in IPM. According to the inventors' research, in all of the previously known bottle formulations, pack formulations, and bunker sheets, the natural enemy insect utilized is one type of phytoseiid mite selected from polyphagous phytoseiid mites, such as Phytoseiulus californicus, Phytoseiulus swirskii, and Phytoseiulus cucumeri, depending on the type of pest to be controlled. Furthermore, while bottle formulations are known as examples of using Gamas mites as natural enemies, there are no known examples of using Gamas mites as natural enemies in pack formulations or bunker sheets. Furthermore, according to the inventors' research, in all of the bottle formulations, pack formulations, and bunker sheets, there are no known examples of using multiple types of natural enemy insects contained within the same material, which is the inventor's idea and one of the objects of the present invention.

However, bottled and packaged formulations are susceptible to environmental changes such as temperature and humidity, and a major issue is that their effectiveness is not stable under greenhouse cultivation conditions in Japan. Meanwhile, according to the inventor's research, while bunker sheets are effective in protecting natural enemy insects (effective as a shelter), there remain issues with the reproduction efficiency of natural enemy insects, and this is thought to be a practical issue when widely deploying them in greenhouse horticultural crops (vegetables, fruit trees, flowers, etc.). As mentioned above, according to the inventor's research, for example, when using bunker sheets that utilize Phytoseiulus swirskii as a natural enemy insect, depending on environmental conditions such as temperature and humidity, the mites do not multiply significantly, and placing a packaged formulation in the bunker sheet may not result in a significant improvement in reproduction efficiency.

As explained above, bunker sheets contain a pack formulation, water-retaining materials (such as water-absorbent polymers that retain water) to promote the proliferation of natural enemy insects, and felt to serve as an egg-laying site. However, according to the inventor's research, even with bunker sheets that meet these requirements, no dramatic improvements were observed in the number of Phytoseiulus swirskii mites released or the release period, particularly in cases where Phytoseiulus swirskii mites were used as natural enemy insects. For this reason, the inventor recognized that an important technical challenge would be to introduce some kind of new technology to bunker sheets that already use Phytoseiulus swirskii mites as natural enemy insects, thereby improving the number and release period of Phytoseiulus swirskii mites, and that solving this problem is urgently needed to promote the spread of IPM (integrated pest management).

Furthermore, as mentioned above, conventional pack formulations and bunker sheets using pack formulations contain only one type of natural enemy insect selected from phytoseiid mites in each pack formulation. However, there are multiple species of micro-pests that attack greenhouse horticultural crops, and the optimal natural enemy insect for each micro-pest is often different. For this reason, to control multiple species of micro-pests within a greenhouse, it is necessary to use multiple pack formulations. This has posed a major problem in the practical application of pest control technology using pack formulations, as they are more expensive than chemical pesticides, which are effective against multiple species of micro-pests with a single product.

After extensive research into the above situation, the inventors have discovered that the following are important in order to increase the breeding efficiency of natural enemy insects in bunker sheets and to improve the number and duration of release of natural enemy insects. First, as described in Patent Document 2 cited above, it is said that the application of a moisture-sustaining, sustained-release material makes it possible to "create high humidity conditions (70% RH or higher) within the space of the bunker sheet that are suitable for the breeding of natural enemy insects and feeding mites, and to stably maintain this condition for an extended period of time," which is an effective method.

However, as mentioned above, the inventor's research has revealed that the moisture content achieved using the water-retaining material included with commercially available bunker sheets does not stably achieve the objectives of the present invention. In other words, the inventor has discovered that in order to improve the number and duration of release of natural enemy insects, it is effective to place water-retaining material with a higher moisture content within the bunker sheet. Furthermore, as a result of further research, the inventor has found that, for example, even if the water-retaining material were made more functional and the moisture content of the water-retaining material placed within the bunker sheet were reliably increased compared to conventional methods, the effect would be improved compared to conventional methods, but would not result in a dramatic improvement in the number and duration of release of natural enemy insects.

In response to this situation, the inventors conducted extensive research into improving bunker sheets that use Phytoseiulus swirskii as a natural enemy insect, a representative example of phytoseiid mites, and arrived at the present invention. Specifically, in order to achieve the first object of the present invention, in addition to using a moisture-retaining material made from a moisture-slow-releasing water-retaining material to "maintain high humidity conditions (70% RH or higher) within the space of the bunker sheet for an extended period of time," as has been done conventionally, they concluded that the requirement that this water-retaining material "contain bait that has been moistened using an aqueous solution containing sugars" would be highly effective and necessary.

As mentioned above, it is already known that "maintaining high humidity conditions (70% RH or higher) within the bunker sheet space for an extended period of time" is effective in preventing the habitation of phytoseiid mites. To achieve this, a water-retaining material such as a superabsorbent polymer is used, and the water-retaining material is placed within the bunker sheet space. This configuration is said to achieve "maintaining high humidity conditions (70% RH or higher) within the bunker sheet space for an extended period of time." The inventor conducted detailed research on this point. As a result, it was first confirmed that the use of the water-retaining material used in the embodied product resulted in an increase in the total number of natural enemy insects released and a longer release period compared to when no water-retaining material was used.

In this case, we discovered that by replacing conventional products on the market with water-retaining materials containing a highly water-absorbent polymer, for example, and placing them inside the bunker sheet, we were able to achieve a longer release period for natural enemy insects compared to conventional devices. Specifically, the space inside the bunker sheet is small and can accommodate approximately five pieces of water-retaining material. However, the water-retaining material used in conventional products (0.5 g per five pieces) retains 2-3 g of water when fully filled. In contrast, if a more water-absorbent material is used, the five pieces retain 4-7 g of water, achieving a higher water content than conventional products. Furthermore, according to the inventors' research, simply using such water-retaining materials with a higher water content, retaining 4-7 g of water per five pieces, and more preferably 5-7 g of water, can achieve a longer release period compared to conventional water-retaining materials. Specific examples of this point will be described later. Additionally, one way to increase the water retention capacity using water-retaining materials used in conventional products is to increase the number of water-retaining materials. However, in this case, it is necessary to increase the space inside the bunker sheet, which means that the shape of the bunker sheet must be changed and made larger.

After further investigation, the inventors discovered that introducing artificial bait into the bunker sheet that can be utilized by natural enemy insects and prey mites is effective and highly effective. Furthermore, this can be easily achieved by effectively utilizing the water-retaining material described above to incorporate bait that has been moistened with an aqueous solution containing sugars, and that this configuration produces significant benefits. Specifically, the inventors discovered that sugars are the optimal artificial bait, and that the objective of the present invention can be achieved by incorporating this bait into the bunker sheet as a water-retaining material by forming an aqueous solution containing sugars. Sugars readily dissolve in water to form an aqueous solution, which can also be used to moisten the moisture-sustaining moisture-retaining material described above, which maintains high humidity conditions (70% RH or higher) within the bunker sheet for extended periods. The inventors' investigations revealed that the sugars placed within the bunker sheet by this simple method serve as bait for the natural enemy insects and prey mites that inhabit the bunker sheet, thereby promoting their continued proliferation and thereby effectively achieving the objective of the present invention. Examples of sugars that make up the present invention include trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol, and erythritol, and any of these can be used, and the effects of the present invention can be achieved by using these as feed.

Although details will be provided later, a more preferred embodiment of the present invention involves using monosaccharides, disaccharides, or sugar alcohols among sugars as the "artificial bait available to natural enemy insects and bait mites within the bunker sheet," or using substances containing nitrogenous components in addition to sugars. According to the inventor's research, by using monosaccharides or substances containing nitrogenous components in addition to sugars, it is possible to increase the number of natural enemy insects released from the bunker sheet without increasing the sugar concentration, and to extend the release period of the natural enemy insects. The nitrogen components of the above substances can be either nitrogen components in organic matter or inorganic components in inorganic compounds.

Examples of nitrogen-containing substances used in the present invention include peptone, yeast, urea, amino acids, and vitamins. As with sugars, these substances can be easily placed within the bunker sheet by dissolving them in the aqueous solution used to maintain a high humidity level in the moisture-retaining material used to maintain the moisture-releasing properties of the bunker sheet. This provides effective bait for insect predators and mites. Other substances, such as aqueous solutions containing minerals, may also be used. The yeast referred to above is a "microorganism, i.e., a bacterium, that breaks down sugars into alcohol and carbon dioxide (performs alcoholic fermentation) and is used to ferment foods and alcoholic beverages." Any yeast used in fermented foods can be used. Specific yeasts that can be used in the present invention include beer yeast, wine yeast, baker's yeast (yeast, natural yeast), and miso yeast. In the above, yeast is a yeast specifically for bread, which is basically a single type cultivated, while natural yeast is a yeast cultivated from natural sources such as grains and fruits.

Furthermore, after extensive research, the inventors have come to the new realization that, in addition to the above-mentioned conditions, by adopting a "new configuration in which a different species of prey mite is introduced that can utilize the newly introduced artificial bait and in which multiple species of prey mites are used in combination," it is possible to maintain a large number of prey mites for natural enemy insects contained within the bunker sheet for a longer period of time compared to currently used commercially available bunker sheets. In other words, in order to achieve the first objective of this invention at a higher level, it is effective to use a water-retaining material that "contains bait that has been moistened using an aqueous solution containing sugars," and to use multiple species of prey mites for natural enemy insects in combination within the bunker sheet, whereas conventional technology only uses one type of mites. The inventors have recognized that this configuration will result in a technology that can achieve the above-mentioned effects at a higher level and in a more stable manner.

Based on this understanding, the inventor conducted the following study to determine the feasibility and advantages of replacing the single type of bait mite housed in the bunker sheet with a configuration using multiple species of natural enemy insects. Specifically, the inventors considered the use of two types of bait mites, T. sugari and T. acarus, as a representative example, and the conditions for doing so. Note that commercially available bunker sheets use either T. sugari or T. serrata as the bait mite; when the natural enemy insect is Phytoseiulus swirskii, T. sugari is used as the bait mite. T. sugari belongs to the family Acaridae, and T. acarus belongs to the family Sarcoideae, both of which are classified in the suborder Acaridae. The mites of the Acaridae family used as bait mites in addition to T. sugari used in the study above are also classified in the suborder Acaridae, such as T. putrefactive mites.

The present inventors conducted various laboratory evaluation tests using Phytoseiulus swirskii and obtained the above findings, leading to the present invention. First, they discovered a new composition using a slow-release moisture-retaining material containing a bait-filled material that was moistened with an aqueous solution containing sugars. This dramatically improved the number and duration of release of the natural enemy insect, Phytoseiulus swirskii. In other words, the use of a bait-filled water-retaining material alone achieved a groundbreaking effect on the proliferation of natural enemy insects compared to the use of conventional water-retaining materials that were moistened with water. The present inventors discovered that adding the following innovations to the effective "water-retaining material containing bait" for the natural enemy insects would be even more effective. Specifically, currently used pack formulations using Phytoseiulus swirskii contain one species of sugar mite as a prey mite for Phytoseiulus swirskii. However, they confirmed that even greater effectiveness could be achieved by using a grain mite as a prey mite in addition to the sugar mite. In this case, it is preferable to configure the system so that the initial density of sugar mites is greater than the initial density of astigmatids. Specifically, a more stable effect can be achieved by setting the initial density of bait mites at, for example, 500-1500 sugar mites and 2-40 astigmatids. For example, it is more preferable to set the initial density of sugar mites at about 1000 and the initial density of astigmatids at about 5-20. The effects of the present invention will be explained below with an outline of a study example.

The inventors have discovered that by modifying the bunker sheet to conform to the configuration defined by the present invention, the number and duration of release of natural enemy insects from the bunker sheet can be increased by approximately 1.5 to 2 times compared to conventional bunker sheets, resulting in dramatic improvements. First, we will explain the case where the bait mites in the bunker sheet are a combination of sugar mites and astigmatids, instead of the sugar mites used in conventional products. According to the inventors' studies, when a bunker sheet containing two types of bait mites, sugar mites and astigmatids, was used, and when tested under temperature and humidity conditions of, for example, 25°C and 75% RH, Phytoseiulus swirskii in the pack formulation first multiplied by feeding on the sugar mites, which were in greater numbers, for one to three weeks after installation, then multiplied by feeding on sugar mites and astigmatids for the next four to five weeks, and then multiplied mainly by feeding on astigmatids from six weeks onward. In contrast, when a bunker sheet using a conventional pack formulation containing only sugar mites as bait mites was used, and tests were conducted under temperature and humidity conditions of 25°C and 75% RH, it was found that the food supply became insufficient and the proliferation of Phytoseiulus swirskii ceased within about 4 to 5 weeks. In contrast, as described in detail below, the proliferation of Phytoseiulus swirskii in a bunker sheet containing both sugar mites and acarid mites as bait mites continued for a significantly longer period of time than the proliferation of Phytoseiulus swirskii in a conventional bunker sheet.

The inventors conducted studies using the bunker sheet of the present invention, which is configured to incorporate the aforementioned bait-containing water-retaining material and the two types of prey mites described above, and confirmed that Phytoseiulus swirskii can continue to multiply for up to approximately 13 weeks. Detailed studies revealed that, when newly introduced as prey mites separate from sugar mites in a pack formulation of the bunker sheet of the present invention, the initial population of these mites was smaller than that of sugar mites, but they were omnivorous and reproduced in large numbers by feeding not only on the food for the prey mites, such as bran, contained in the pack formulation, but also on a variety of other materials, including the excrement, carcasses, and mold of prey mites and natural enemy insects. Meanwhile, the multiplication of sugar mites, which were used as prey mites for Phytoseiulus swirskii in the prior art, gradually weakened and were replaced by sugar mites after four weeks from the initial stage. After that, by using the water-retaining material containing bait as explained above, the acarid mites continued to multiply for up to about 13 weeks and functioned as food mites for the Swirlskii mite, which resulted in the sustained proliferation of the Swirlskii mite.

Furthermore, the inventors have found that by using a bunker sheet with a more preferred configuration of the present invention, it is possible to increase the number of Phytoseiulus Swirskii mites released from the bunker sheet, and furthermore, the release of Phytoseiulus Swirskii mites can be maintained for a longer period of time. Specifically, a bunker sheet with a more preferred configuration of the present invention includes, in addition to the pack formulation with the above-mentioned bait mite configuration, a felt member for egg-laying and a moisture-retaining material made of a moisture-slow-releasing water-retaining material. As mentioned above, the water-retaining material contains bait that has been moistened with an aqueous solution containing sugars. By providing the bunker sheet of the present invention with the above-mentioned new and more preferred configuration, the present invention achieves the following remarkable effects.

As described above, the Swirskii mites and prey mites that have continued to multiply in large numbers within the pack move from the pack to the interior of the main body of the bunker sheet. As described above, the main body contains a water-retaining material containing bait, which is maintained with a sugar-containing aqueous solution. Therefore, the Swirskii mites and prey mites feed on the sugars contained in the water-retaining material and further multiply within the main body of the bunker sheet. The felt egg-laying components located in the main body of the bunker sheet are effectively utilized for multiplication. By using a pack containing two types of prey mites, the multiplication of natural enemy insects can be maintained for a longer period of time than with conventional packs containing a single type of prey mite. The Swirskii mites that have multiplied in this way are released into a greenhouse or other facility through an accessible gap in the enclosed space of the main body of the bunker sheet, where they inhabit the facility, feeding on pests such as thrips and whiteflies that infest plants. In this case, as mentioned above, Phytoseiulus swirskii mites continue to multiply within the bunker sheet over a long period of time, making it possible to release large numbers of natural enemy insects from the bunker sheet into the facility over a long period of time. As a result, the technology of the present invention makes it possible to effectively control pests using natural enemy insects over a long period of time.

As mentioned above, the inventors recognized that another object (third object) of the present invention would be to develop an all-in-one bunker sheet that could be used to control different pests over a wider area, both above and below ground, using the same device, something completely unimaginable with conventional bunker sheets. After extensive research into this point, they discovered that, in addition to the improvements made to conventional bunker sheets described above in the preferred configuration, such as "holding an aqueous solution containing sugars and, if necessary, nitrogen components as artificial bait in a water-retaining material" and "using the conventionally used sugar mites as bait mites with the addition of grain mites at an initial population lower than that of sugar mites," it is possible to effectively use two types of natural enemy insects to control pests with a single bunker sheet by adding Gamas mites to a conventionally used type of phytoseiid mite as natural enemy insects, for example, at an initial density of Gamas mites for every 100 phytoseiid mites of the same type. Here, Phytoseiulus swirskii and Phytoseiulus californicus are classified in the Phytoseiidae family, and Gamasidae are classified in the Gamasidae family, but they are all classified in the order Acari and the suborder Gamasida. The following describes the breeding device for natural enemy insects of the present invention, which corresponds to the third object of the present invention mentioned above.

More specifically, in the natural enemy insect breeding device of the present invention, which corresponds to the third objective, for example, if the initial density of Phytoseiulus swarskii is about 200-300 individuals, and the initial density of Gamas mites is about 2-8 individuals, it is possible to achieve the effects of the present invention that could not be achieved by conventional techniques. According to the inventor's research, increasing the number of Gamas mites from the beginning to increase the density would result in the Gamas mites preying on many prey mites, hindering the proliferation of Phytoseiulus swarskii, and would even be eaten by the Phytoseiulus swarskii themselves, which is undesirable. In contrast, if Gamas mites are initially present in small numbers as described above, the Phytoseiulus swarskii mites will first multiply by preying on prey mites such as sugar mites. Then, when the proliferation of Phytoseiulus swarskii mites has settled down, the Gamas mites, which have gradually multiplied from a small number, can prey on prey mites such as astigmatids and multiply explosively. As a result, it was confirmed that after the release of the Swirlskii mites, the bunker sheets were installed inside the facility, and five weeks later, the Gamas mites were released outside, where they preyed on the pests they preferred, making it possible to control other pests.

Furthermore, as described below, in the specification of this application, when explaining the configuration and effects of the present invention, Hypoaspis sp., a type of natural enemy insect of the Gamagridae family, is described as a representative example of the Gamagridae mites, which are natural enemy insects. Furthermore, while further studies, such as confirmation tests of the degree of effectiveness, are desirable before practical application, the present inventors have recognized that when a type of natural enemy insect of the Macrochelidae family (Stratiolaelaps sp.), which belongs to the Gamagridae suborder and has an ecology similar to that of Hypoaspis sp., is used in combination with Phytoseiulus swirskii, both natural enemies can be propagated. The fact that both of the above-mentioned combined natural enemies can be propagated is based on the fact that overseas, examples of Gamagridae mites being used as natural enemy insects include H. miles of the genus Hypoaspis and S. This can be understood from the fact that bottle formulations of Hypoaspis. scimitus are known, and that although no formulations have been developed in Japan, it is known that acarid mites can be used to propagate native natural enemies such as H. yamauchii, which can then be used to control pests. Thus, the technology of the present invention can be applied to various Gamagridae mites that propagate using acarid mites and are capable of preying on underground pests, and can also be used against natural enemy insects of the Macrochelidae family (such as the genus Stratiolaelaps) and the Ascidae family (such as the genus Ascidae), in the same way as with Hypoaspis. sp., which is described as a representative example in the specification of this application.

In other words, by configuring it as described above, it is possible to multiply both Phytoseiulus swirskii and Gamas mites at optimal times in a single bunker sheet, and by releasing these two types of natural enemy insects into a facility from the bunker sheet, each can be used to control a different pest. Specifically, this invention makes it possible to simultaneously control thrips and other insects that damage leaves and flowers with Phytoseiulus swirskii, and fungus gnats that damage roots and soil-level areas with Gamas mites, all in a single bunker sheet. Thus, according to a preferred embodiment of the present invention, Phytoseiulus swirskii can be first multiplied over a long period of time in a single bunker sheet, and then, after the multiplication of Phytoseiulus swirskii has declined, the multiplication of Gamas mites can be activated.

In order to achieve the above-described effects of the present invention, the configuration of a breeding device for natural enemy insects (natural enemy support material) is specified as follows. First, the basic configuration is such that, inside a main body having an enclosed space through which the natural enemy insects can enter and exit, at least natural enemy insects, prey mites that serve as food for the natural enemy insects, small pouch-shaped members containing at least food for the prey mites, a felt member for egg-laying, and a moisture-retaining material made of a moisture-slow-releasing water-retaining material are placed. An example of a product with this basic configuration is the previously described Bunker Sheet (registered trademark).

In the first aspect of the present invention, the pouch-shaped member (pack preparation) is configured so that the natural enemy insect is one type of phytoseiid mite, a representative example of which is Phytoseiulus swirskii, and the bait mite that serves as food for the natural enemy insect is at least one type of phytoseiid mite of the family Caryopsis, a member of the suborder Acaridae, a representative example of which is Caryopsis sugaris. In particular, the water-retaining material contains bait that has been moistened with an aqueous solution containing sugars. This configuration improves the proliferation of phytoseiid mites, a natural enemy insect that inhabits the pouch-shaped member and the main body of the natural enemy insect propagation device, compared to conventional bunker sheets, and as a result, the amount of natural enemy insects for phytoseiid mites released from the propagation device can be increased.

The second aspect of the present invention is characterized in that the bait mite configuration described above includes, in addition to the sugar mites, one type of acarid mite of the Astigmatidae family, a representative example of which is Astigmatidae, belonging to the suborder Acaridae, and the initial density of the acarid mites is set to be lower than that of the sugar mites. This configuration allows the proliferation of phytoseiid mites, a type of natural enemy insect, that inhabit the pouch-shaped member and the main body of the natural enemy insect breeding device to continue for a longer period of time than with conventional bunker sheets, further improving proliferation, and as a result, the release of natural enemy insects from the natural enemy insect breeding device can be maintained in good condition for a long period of time.

Furthermore, a third invention for achieving the third object of the present invention is characterized by a configuration that utilizes two different types of natural enemy insects. Specifically, the third invention is the same as the first or second invention described above, except that the natural enemy insect configuration further includes Gamas mites as natural enemy insects, and the initial density of the Gamas mites is an essential requirement of 1 to 3 per 100 of the one type of phytoseiid mites. As will be described later, this configuration allows Gamas mites to multiply after the proliferation of the phytoseiid mites has stabilized after a satisfactory proliferation of the natural enemy phytoseiid mites. This makes it possible to release different types of natural enemy insects from a single natural enemy insect propagation device, making it possible to control multiple types of pest insects within a facility. Until now, the idea of the third invention mentioned above - that of efficiently multiplying multiple species of natural enemy insects with different ecologies such as feeding habits and habitats, for example, in a single pack formulation, thereby enabling the multiplied natural enemy insects to settle in various locations on crops, particularly above-ground parts such as leaves, flowers, and stems, as well as underground parts such as the soil and roots, thereby protecting the entire crop from microscopic pests with the natural enemy insects, has never existed. Of course, there is no technology or natural enemy insect multiplication device that can achieve this.

The natural enemy insect protection device of the present invention will be explained in more detail below using examples. Note that the present invention is not limited in any way by the following examples.

(Test Method)
Various studies were conducted using the Swirl Bunker (registered trademark, manufactured by Ishihara Biosciences), a commercially available natural enemy support material (protection device for natural enemy insects) that requires the worker to assemble the components into a usable configuration at the time of installation on plants, etc. within a facility. Specifically, a waterproof paper assembly container from the components (accessories) of the commercially available product was used for the main body of the natural enemy insect protection device, and black felt from the commercially available components was used for the felt member for egg-laying.

The pack formulation used 250 Swirlskii mites per pack, which are a component of the above-mentioned commercially available product. In the examples of the present invention, we first improved the bait mites in this commercially available pack formulation, and then added Hypoaspis sp., a species of Gamasidae, as another natural enemy insect, and then used each of these to conduct an investigation. Specific methods will be described later.

The water-retaining materials used were the same superabsorbent polymer as the component of the commercially available natural enemy support material (Swirl Bunker) mentioned above, as well as a granular superabsorbent polymer with higher water absorption than that used in the commercially available natural enemy support material. Specifically, the superabsorbent polymer used in the commercially available product weighs approximately 0.05 g per five particles, which weighs 2-3 g per five particles when hydrated. In the tests described below, we primarily used the more absorbent granular superabsorbent polymer, which, as described below, results in a longer-lasting increase in natural enemy insect release and weighs 5-7 g per five particles when hydrated. In the examples of the present invention, five highly absorbent water-retaining materials were used, each of which was hydrated with aqueous solutions containing various sugars. The hydrated water-retaining materials were then placed inside the main body and tested at 25°C and 75% RH. Additionally, the five water-retaining materials placed inside the main body of the natural enemy support material were each placed so that the total weight after water retention was constant, and test conditions were standardized. When commercially available natural enemy support material is actually used to release natural enemy insects, the granular superabsorbent polymer that makes up the product is used as the water-retaining material by retaining it with water; in this case, tap water is considered sufficient. However, in the tests below, distilled water was used as the aqueous solution used for hydration, taking into consideration the effect on mites of trace components contained in tap water. Hereinafter, this will sometimes be referred to simply as water.

The effectiveness of each type of natural enemy support material was confirmed using the following procedure. Each natural enemy support material was placed in a container with the humidity adjusted to 75% RH at 25°C. Every week, the support material was removed and the container was replaced, and the number of natural enemies remaining in the container after replacement was counted. Each natural enemy support material was investigated in this manner until no more natural enemy insects were released from the natural enemy support material.

(Confirmation test on the effectiveness of using water-retaining materials)
The effect of installing a water-retaining material (granular superabsorbent resin), which is a component of the commercially available natural enemy support material described above and is intended to increase the humidity inside the main body of the natural enemy support material, on the release of natural enemy insects was confirmed. First, when a natural enemy support material without a water-retaining material was used, the tendency for the number of natural enemy insects released to increase stopped after about 4 to 5 weeks, although this depended on the installation environment. For example, when the relative humidity of the installation environment was 75% RH. This shows that without using a water-retaining material, under normal environmental conditions, the release of new natural enemy insects from the natural enemy support material ceases after about 4 to 5 weeks.

Therefore, natural enemy support materials were placed in containers with humidity controlled at 25°C and 75% RH, and we investigated whether there was a difference in the release of the natural enemy insect, Phytoseiulus swirskii, when two types of water-retaining materials with different water contents were used. Specifically, we used natural enemy support materials that were moistened with distilled water and contained low-water-content materials with a total weight of 2g to 3g for five pieces, and high-water-content materials with a total weight of 5g to 7g for five pieces, and placed each in a container with humidity controlled at 25°C and 75% RH for testing. We then replaced the containers for each natural enemy support material every week, counting the number of natural enemies remaining in the containers after each replacement, and confirmed the release of natural enemy insects.

As mentioned above, it is known that when natural enemy support materials containing water-retaining materials are used, the period during which the number of natural enemy insects released increases can be prolonged compared to when no water-retaining materials are used. In contrast, tests conducted by varying the water content of the water-retaining materials revealed that the degree to which the period during which the number of natural enemy insects released increases varies depending on the water content of the water-retaining material. Specifically, when five water-retaining materials with a total weight of 2g to 3g were placed, the trend toward an increase in the number of natural enemy insects released stopped after four to five weeks, whereas when five water-retaining materials with a total weight of 5g to 7g were placed, the trend toward an increase in the number of natural enemy insects released was prolonged, with proliferation continuing for up to eight weeks, after which the trend toward an increase in the number of natural enemy insects released stopped. The above results show that compared to using water-retaining material contained in commercially available natural enemy support materials, which are wet before use and have a total weight of 2g-3g for five pieces when wet, simply using a highly water-absorbent superabsorbent resin water-retaining material with a total weight of 5g-7g for five pieces when wet can extend the release period by approximately 3-4 weeks compared to conventional methods.

(Tests on the improvement of bait mites and water-retaining materials)
To achieve the object of the present invention of increasing the release of phytoseiid mites at a higher level, we investigated the improvement of the bait mites contained in commercially available pack formulations for natural enemy insects. Specifically, we added acarid mites to sugar mites, which have traditionally been used in pack formulations, and conducted a test to confirm the effect achieved by using these mites in combination as bait mites. Furthermore, the inventors conducted the following test to solve the problem of a shortage of bait materials for natural enemy mites and bait mites, which is a concern due to the change in the composition of the bait mites.

As mentioned above, commercially available packs of natural enemy support materials contain sugar mites as food for the natural enemy insect, Phytoseiulus swirskii, and also contain bran and other food for the sugar mites. Sugar mites are known to infest sugar and miso paste, and are known not to spread over a wide area. In the tests in the examples, this pack was used with sugar mites and grain mites added as food mites. Specifically, the pack contained approximately 500 to 1,500 sugar mites, and 2 to 40 grain mites were added for each pack used in the study.

When the right conditions are met, astigmatid mites are known to multiply in large numbers in just one to two weeks. They ingest, for example, wheat flour, breadcrumbs, baking powder, mixed flour with seasonings, sugar, confectionery, etc., and appear in these foods. Among these, Tyrophagus putrescentiae are known to be the most widespread. Tyrophagus putrescentiae were used in the tests of the present invention. The inventors considered it important to control the proliferation of sugar mites and astigmatid mites, which occurs when the composition of the bait mites in the pack formulation is changed to multiple species as described above, so as to contribute to achieving the objectives of the present invention.

The inventors first considered that an effective method for controlling the proliferation of sugar mites and acarid mites would be to significantly reduce the initial density of sugar mites and acarid mites within the pack formulation, as previously mentioned, by significantly reducing the number of acarid mites compared to the number of sugar mites. By configuring the pack formulation in this way, the proliferation of sugar mites would be promoted within the pack formulation first, and then, as the proliferation of sugar mites slows, acarid mites will proliferate in large numbers, and as a result, bait mites will be present in abundance within the pack formulation for a long period of time.

Furthermore, with the above-mentioned configuration, the Swirlskii mites and prey mites that have multiplied in large numbers within the pack formulation will emerge from the pack formulation into the sealed space of the main body of the natural enemy support material in which the pack formulation is placed. The inventors predicted that if, when this state is reached, it is possible to effectively provide food for the prey mites within the sealed space, it will be possible to further multiply the Swirlskii mites, a natural enemy insect, within the sealed space, and as a result, it will be possible to increase the number of natural enemy insects released from the sealed space and extend the period of release.

The inventors conducted extensive research based on the above predictions and discovered that the water-retaining material placed in sealed spaces to maintain high humidity in conventional technology can be effectively utilized. Specifically, the inventors added sugars to the water used to retain water in the water-retaining material, and placed this water-retaining material in the sealed space of the main body of the natural enemy support material in a form containing bait. They then conducted a test to determine whether the sugars introduced into the sealed space could effectively function as food for mites. As a result, they discovered its effectiveness. The procedure is shown below.

In the examples of the present invention, various sugars were dissolved in 100 ml of water used for water retention to prepare an aqueous solution for water retention. The resulting aqueous solution was then used to retain water in water-retaining materials. Five water-retaining materials were then retained until they weighed 5-7 g, and the resulting bait-filled water-retaining materials were placed in an enclosed space. These natural enemy support materials were then placed in containers with a humidity-controlled 75% RH, which were then placed in an incubator set at 25°C. The release test was continued by replacing the containers every week, and the number of natural enemy insects, Phytoseiulus swirskii mites, released into the replaced empty containers was counted, and this number of released mites was used to verify the release status of the natural enemy insects. In the comparative examples, natural enemy support materials were used that contained water-retaining materials weighing 5-7 g, retained only in water. As previously mentioned, the natural enemy support material contained a small amount of sugar mites and a grain mite as bait mites in the packed formulation contained therein. Additionally, for reference, only the pack formulation contained in a commercially available natural enemy support material was used, and placed in a container with humidity adjusted to 75% RH as described above, and the release of the natural enemy insect, Phytoseiulus swirskii, from the pack formulation was confirmed. Note that the conventional pack formulation only contains sugar mites as bait mites.

First, tests were conducted by placing bait-containing water-retaining materials, which had been moistened with a highly concentrated aqueous solution of sugars, within the enclosed space of the natural enemy support material. Specifically, the amount of sugar dissolved in 100 ml of water was kept constant at 50 g. Naturally occurring sugars, such as trehalose, honey, brown sugar, and molasses, were used as the sugars, and aqueous solutions containing these sugars were prepared at high concentrations. Each of the resulting solutions was then used to moisten a superabsorbent polymer (water-retaining material) so that five pieces weighed 5-7 g. These bait-containing water-retaining materials were then used for testing. One ml of a fungicide was also added to each of the above solutions. Fungicides have the effect of inhibiting the growth of various microorganisms, such as gram-positive bacteria, gram-negative bacteria, and mold, that can cause spoilage of bait-containing water-retaining materials. Preferably, the fungicide is approved as a food additive. In the tests below, Desfan-10 (trade name: manufactured by Matsuo Pharmaceutical Co., Ltd.), a naturally derived antibacterial preparation extracted from grapefruit seeds, was used as one of the antibacterial agents that met these conditions. Hereinafter, this will sometimes be simply referred to as the antibacterial agent.

The test results confirmed that, depending on the type of sugars contained in the aqueous solution used for water retention, a large number of predatory mites, Phytoseiulus swirskii, were released continuously from the start of the test, increasing in number from the beginning until 10 to 13 weeks after the start of the test. In contrast, in the comparative example, which used a bait-free water-retaining material so that five pieces weighed 5 to 7 g, fewer predators were released from the beginning compared to the example, and the number of predators released did not increase after 8 weeks. For reference, in a test using only the pack formulation, the release period of the predatory mites, Phytoseiulus swirskii, was approximately four weeks. Furthermore, in a confirmation test using only the pack formulation in an environment with a humidity of approximately 40% RH, the release period was approximately two weeks, and the number of predatory mites released was very low. These results confirm that increasing the humidity of the environment in which the pack formulation was placed to 75% RH was an effective means of extending the release period of predatory insects and increasing the number of predators released.

Table 1 below shows the total number of natural enemy insects released, calculated by accumulating the number of Phytoseiulus Swirskii mites counted during the release period. As a result, in the comparative example where a water-retaining material without bait was used that had been soaked in water until it reached 5-7g, the release period was 8 weeks and the total number of natural enemy insects released was 587.8, as shown in Table 1. In contrast, as shown in Table 1, when the material was soaked in an aqueous solution containing a sugar, the release period and number of Phytoseiulus Swirskii mites released were significantly increased regardless of the sugar used.

The "Total number of natural enemy insects released during the period" in Table 1 is the arithmetic mean value obtained by counting the cumulative total number of Phytoseiulus Swirskii mites for each test as described below, repeating the same test five times, and using the cumulative total counts for each test. That is, for each test, five samples (5-7 g) of each natural enemy support material, each containing a different sugar in the aqueous solution used for water retention, were used to conduct the test. The number of adult female Phytoseiulus Swirskii mites released into empty containers replaced every week was counted, and this procedure was repeated until release was complete. The cumulative total of the count results obtained was used as the cumulative total for that test. The number in parentheses for "Total number of natural enemy insects released during the period" in Table 1 is the increase factor calculated based on the cumulative count result (587.8 mites) of the comparative example, conducted using natural enemy support material retained in water.

As shown in Table 1, it has been verified that adding sugars, which serve as food for mites, to the aqueous solution used to retain water in the water-retaining material effectively contributes to extending the release period of natural enemy insects and increasing the total number of insects released. Specifically, it was confirmed that compared to the comparative example in which a water-retaining material without food was used, the release period was extended by 2 to 5 weeks, and the total number of insects released could be increased by approximately double.

In integrated pest management (IPM), which involves breeding natural enemy insects and using them to control pests, it is desirable to reduce running costs as much as possible and control pests economically. However, as the test results above show, this invention has made it possible to effectively breed natural enemy insects by using safe materials, and is expected to become a technology that can make the use of natural enemy support materials used to control pests more efficient.

However, in the above test, a high-concentration aqueous solution of 50 g of sugar dissolved in 100 ml of water was used to retain water in the water-retaining material, and in order to reduce the running costs of IPM, it is desirable to use a smaller amount of sugar. Therefore, the inventor conducted a test to examine the release of natural enemy insects when using a water-retaining material that was retained with an aqueous solution containing a reduced amount of sugar, using a method similar to that described above. The results obtained are summarized in Table 2. For trehalose, the results for when the high-concentration aqueous solution shown in Table 1 above was used to retain water in the water-retaining material are also reproduced here.

As shown in Table 2, we investigated whether it would be possible to extend the release period of natural enemies and increase the total number of released insects by using water-retaining materials containing a dilute aqueous solution of 1 g of sugar dissolved in 100 ml of water. Specifically, we conducted the release test in the same manner as above, except that we varied the sugars added to the aqueous solution used to retain the water in the materials and made the concentration more dilute. That is, the test was conducted five times at a humidity of 75% RH and 25°C. As a result, as shown in Table 2, it was confirmed that the number of released insects was improved when monosaccharides such as glucose and fructose, disaccharides such as trehalose and sucrose, or sugar alcohols such as sorbitol and erythritol were used as sugars. As shown in Table 2, when the sugars trehalose, fructose, sucrose, and erythritol were used, the number of Phytoseiulus swirskii adult females released from the container each week was greater than the number released from the container each previous week, for at least 10 weeks. This confirms that sugars contribute to the continued proliferation of Phytoseiulus swirskii for long periods of time within the natural enemy support material and in the container containing the natural enemy support material, even when the water retention material is retained using a dilute aqueous solution.

As mentioned above, sugars have been found to be useful substances that can make it possible to continuously release large numbers of natural enemy insects, as targeted by this invention, over a long period of time, by using water containing bait to retain moisture in the water-retaining material, not only when a concentrated aqueous solution with a high bait content is used to hydrate the water-retaining material and the material is placed inside a bunker sheet, but also when a dilute aqueous solution with a low bait content is used to hydrate the water-retaining material and the material is placed inside a bunker sheet.

Furthermore, the results of the above tests showed that the effects of the present invention were greater when a highly concentrated sugar solution was used; however, when a sugar solution with 1/50th the concentration was used, the effects were slightly reduced, but the intended effects of the present invention were clearly achieved. From this, it is expected that the effects of the present invention can be more effectively achieved by using a sugar solution with an appropriate intermediate concentration as discussed above. Furthermore, it is expected that the effects of the present invention can be more effectively achieved by examining more optimal types of sugars or combinations of sugars with other substances containing nitrogen components.

Therefore, the inventors conducted research to determine whether using an aqueous solution containing a sugar that exhibits these effects and another substance to retain water could increase the number of natural enemy insects released or enable the natural enemy support material to maintain a good release of natural enemy insects for a long period of time. Specifically, trehalose was used as a representative sugar, and a dilute concentration of 1 g of sugar dissolved in 100 ml of water was investigated to determine whether adding 1 g of a nitrogen-containing substance would improve the effect. Protein-derived peptone was also investigated as a nitrogen (N)-containing substance. As shown in Table 2, the results confirmed that using a water-retaining material retained with an aqueous solution containing a nitrogen (N)-containing substance in addition to trehalose could increase the number of Phytoseiulus swirskii mites released compared to using a small amount of sugar alone. Other nitrogen (N)-containing substances that can be used include urea, yeast, amino acids, and vitamins. Among these, the addition of yeast was found to be effective. This point will be discussed later.

Figure 1 shows the results of the study conducted using Phytoseiulus swirskii as a representative example of phytoseiid mites, a natural enemy insect, as shown in Tables 1 and 2 above. The cumulative weekly release of phytoseiid mites (number of adult female natural enemy insects) measured as described above is plotted as a graph. As shown in Figure 1, the intended effect of the present invention can be achieved by using an aqueous solution of sugars to retain moisture in the water-retaining material contained within the bunker sheet specified in the present invention. In Figure 1, trehalose is abbreviated as "Treha," erythritol as "Eris," and fructose as "Fluc."

(Examination of natural enemy insects other than phytoseiid mites)
The commercially available pack of natural enemy support material used in each of the above-mentioned tests contained the natural enemy insect Phytoseiulus swirskii. In a more preferred embodiment of the present invention, as described above, this pack was modified to include, in addition to the sugar mites contained in the commercially available pack, a significantly smaller number of acarid mites as prey for the swirskii mites. Furthermore, a water-retaining material containing bait maintained with an aqueous solution containing sugars was placed within the natural enemy support material. This enabled the stable release of Phytoseiulus swirskii mites over a long period of time, and a stable increase in the total number of mites released from a single natural enemy support material. As described above, simply placing a water-retaining material containing bait maintained with an aqueous solution containing sugars within the natural enemy support material can enhance the release of natural enemy insects. As described above, the use of a water-retaining material containing bait maintained with an aqueous solution containing sugars in combination with a different type of bait mite can further enhance the release of natural enemy insects.

Furthermore, in another configuration example of the present invention, we have found that by adding a simple means, in addition to the above-mentioned effects, it is possible to achieve a completely different effect, as described below. That is, we have found that a single natural enemy support material can be used to effectively release both phytoseiid mites, such as Phytoseiulus swirskii, and other natural enemy insects that can be used to control other pests, different from phytoseiid mites. Specifically, we conducted the following study using Hypoaspis sp., a natural enemy insect of the Gamagidae family, as a natural enemy insect in addition to phytoseiid mites. As a result, we confirmed the effectiveness of a natural enemy support material that combines two natural enemy insects: phytoseiid mites, such as Phytoseiulus swirskii, and Gamagidae, such as Hypoaspis sp. The natural enemy insect of the Gamagidae family, Hypoaspis sp., used in the above study. sp. were grown by feeding field-collected Gastrula mites with springtails that had also been collected in the field and grown indoors using baker's yeast, etc.

A small number of the aforementioned Gamas mites (Hypoaspis sp.) were added to a pack formulation modified with the addition of acorn mites as bait, which had been shown to be effective in previous studies. Specifically, 2-8 Gamas mites were added to approximately 250 Phytoseiulus swirskii mites contained in the pack formulation. A moisture-retaining material filled with distilled water was then filled with bait, as in the previous study, and placed in the main body of the natural enemy support material. Using this natural enemy support material modified with bait mites and natural enemy insects, the containers were replaced weekly, as previously performed, and the number of Gamas mites released from each container was counted to confirm the Gamas mites' proliferation status. As shown in Figure 2, there were almost no Gamas mites in the containers until three weeks later, but release began after four weeks, and the number of Gamas mites released rapidly increased and remained stable until approximately nine to ten weeks later. This shows that in the above test, as shown in Figure 1, when the water retention material was filled with distilled water, release of Phytoseiulus swirskii mites began one week after the test, and the increase in the number of released mites almost stopped after four weeks, while release of Gamas mites began after that.

The effectiveness of using an aqueous solution containing sugars to retain moisture in a water-retaining material for the proliferation (release) of Gamas mites was confirmed as follows. An aqueous solution was prepared by adding 50 g of honey to 100 ml of distilled water, and an aqueous solution was prepared by adding 1 g of trehalose and 1 g of urea to 100 ml of distilled water. Water-retaining materials were then retained in these aqueous solutions, and the proliferation (release) of Gamas mites was confirmed in the same manner as in the case of Phytoseiulus swirskii mites. 1 ml of a fungicide was added to each of the above aqueous solutions. The results are shown in Table 3 and Figure 2.

(Examination test on feeding conditions for water-retaining materials with reduced running costs)
The commercially available natural enemy support material (product name: Swirlbanker) used in each of the above-mentioned tests contained a pack of Phytoseiulus swirskii as a natural enemy insect and one species of phytoseiid mite as a bait mite. In a preferred embodiment of the present invention, as described above, a small number of acarid mites are added to the commercially available pack of phytoseiid mite as bait mites in addition to phytoseiid mite. Furthermore, a moisture-retaining material containing bait, which is maintained with an aqueous solution containing sugars, characteristic of the present invention, is placed within the natural enemy support material. This configuration allows for an increased total number of phytoseiid mites released. Meanwhile, as described above, considering the impact on food safety and producer health, the widespread use of IPM technology is urgently needed. To achieve widespread use of IPM, it is important to achieve stable IPM effects while simultaneously reducing IPM running costs. To achieve this, it is desirable to reduce the amount of sugar used and, further, to reduce the types and number of bait mites contained. Therefore, the inventors used a water-retaining material containing bait that was kept moist using an aqueous solution with a reduced amount of sugar, in the same manner as described above, and conducted tests to examine the release of natural enemy insects when no acarid mites were added, in other words, when the only difference was that the water-retaining material of a conventional natural enemy support material was that it contained bait, and confirmed the effectiveness of using a water-retaining material containing bait.

Specifically, we used a commercially available natural enemy support material (product name: Swirl Bunker) in a pack formulation. The water-retaining materials were placed inside bunker sheets containing the pack formulation, and the release of Phytoseiulus swirskii mites from the bunker sheets was examined in the same manner, except that the water-retaining materials were retained with the following five solutions: water; 100 ml of water plus 1 g of fructose and 1 g of peptone; 100 ml of water plus 1 g of sucrose and 1 g of peptone; 100 ml of water plus 1 g of trehalose and 1 g of peptone; and 100 ml of water plus 1 g of trehalose and 1 g of brewer's yeast. The five solutions used were all dilute: water, a solution containing 1 g of fructose and 1 g of peptone in 100 ml of water, and a solution containing 1 g of trehalose and 1 g of brewer's yeast. Each solution contained 1 ml of a mildewproofing agent. The amount of solution used to retain the water in the water-retaining materials was the same, 2-3 g. The test was also repeated 8 to 10 times in an environment of 25°C and relative humidity of 50 to 60%, and the number of Phytoseiulus swirskii mites released from the bunker sheet was counted and the average numbers were compared. The results are summarized in Table 4.

<Evaluation results>
As shown in Table 4, we found that by using a moisture-retaining material containing a dilute aqueous solution of sugars and nitrogenous components, the total number of natural enemy insects, Phytoseiulus swirskii, released increased, just as with conventional pack formulations that do not contain acarid mites, even when only sugar mites were used as prey for natural enemy insects. The addition of brewer's yeast, which contains nitrogenous components, was particularly effective, and we confirmed that combining it with a dilute concentration of trehalose produced the greatest increase in total number released. Meanwhile, the release period of the natural enemy insect, Phytoseiulus swirskii, was roughly the same in each group, at about six weeks, and there were no significant differences due to the difference in the moisture-retaining solution used in the moisture-retaining material. The inventors believe that the reason for this is that the test results shown in Table 4 were obtained by adding a small number of acarid mites in addition to sugar mites to the bait mites in the pack formulation, unlike the previous test examples, and furthermore, the amount of liquid used to retain water in the water-retaining material was small, at 2 to 3 g, so that after four weeks from the start of the test, the proliferation of sugar mites, which are the bait mites, weakened, and thereafter there was a shortage of food for the natural enemies.

The commercially available natural enemy support material used in each of the above-mentioned tests was for "control of whiteflies and thrips." The pack formulation of this natural enemy support material contained the natural enemy insect Phytoseiulus swirskii and one species of prey mite, Caryopsis sugaris. Meanwhile, the commercially available natural enemy support material pack formulation for "control of spider mites" contained the natural enemy insect Phytoseiulus californicus and the prey mite, Glycyrrhiza serrata. As previously mentioned, previous studies of the present invention found that by using a commercially available pack formulation and placing a water-retaining material containing bait, which was moistened with an aqueous solution containing sugars, within the natural enemy support material, the total number of Phytoseiulus swirskii mites released could be increased compared to the comparative example, in which a water-retaining material without bait was used. Furthermore, it was discovered that by adding a small number of acarid mites as bait mites to the commercially available pack formulation contained within the natural enemy support material, in addition to the sugar mites contained in the pack formulation, the high proliferation effect of Phytoseiulus swirskii can be made more stable and sustained.

To promote the widespread use of IPM (integrated pest management), a technology is needed that can steadily increase the number of various types of phytoseiid mites released, and that can address a variety of difficult-to-control micro-pests. Therefore, using a method similar to that used to confirm the proliferation effect of Phytoseiulus swirskii mentioned above, the inventors conducted a test to examine the release of Phytoseiulus californiae, using another species of Phytoseiidae (Phytoseiidae) as the natural enemy insect, and a water-retaining material containing a reduced amount of sugar. Furthermore, according to the inventors' investigations, when Phytoseiulus californiae was used as the natural enemy insect, adding acarid mites to the bait mites in the pack formulation did not have the same effect on the proliferation of natural enemy insects as in the case of Phytoseiulus swirskii. Therefore, as described below, a test was conducted using a water-retaining material containing bait, rather than adding acarid mites to the bait mites.

Specifically, a commercially available natural enemy support material (bunker sheet) was packaged with a pack containing Phytoseiulus californiae mites. The moisture-retaining materials contained within the bunker sheet were similarly treated to examine the release of Phytoseiulus californiae mites from the bunker sheet, except that the moisture-retaining materials were each maintained with the following two liquids. Two liquids were used for moisture retention: water alone, and a dilute solution of water and yeast containing sugars and nitrogen components (100 ml of water, 1 g of trehalose, and 1 g of baker's yeast). Each solution contained 1 ml of a mildewproofing agent. The amount of liquid used to retain moisture in the moisture-retaining materials was the same, 4-5 g, for both types. The test was repeated seven times at 25°C and 50-60% relative humidity. The number of Phytoseiulus californiae mites released from the bunker sheet was counted, and the average number was compared. The results are summarized in Table 5.

As shown in Table 5, we discovered that using a bait-containing moisture-retaining material containing dilute concentrations of trehalose and baker's yeast promoted the proliferation of the prey mite, Glycine maxillaris, even without the addition of acarid mites, and also led to an increase in the total number of prey mite, Phytoseiulus californicus, released, a natural enemy insect. Furthermore, as shown in Table 4, using a bait-containing moisture-retaining material containing dilute concentrations of trehalose and brewer's yeast promoted the proliferation of the prey mite, Carpoglyphus sugarbergii, even without the addition of acarid mites, and also led to an increase in the total number of prey mite, Phytoseiulus swirskii, released, a natural enemy insect. These results confirm that the use of a bait-containing moisture-retaining material can increase the number of phytoseiid mites released, regardless of the type of prey mite or whether acarid mites were added. Meanwhile, the release period for the prey mite, Phytoseiulus californicus, was roughly the same in all plots, at around 7 to 8 weeks, and there were no significant differences due to the differences in the moisture-retaining liquid used in the moisture-retaining material.

Claims (11)

A breeding device for natural enemy insects for improving the breeding of natural enemy insects that are natural enemies of difficult-to-control micro-pest insects,
The main body has an enclosed space through which the natural enemy insects can enter and exit, and at least natural enemy insects, prey mites that serve as food for the natural enemy insects, a small pouch-shaped member containing at least food for the prey mites, a felt member for egg-laying, and a moisture-retaining material made of a moisture-slow-releasing water-retaining material are arranged inside the main body,
The natural enemy insect is a phytoseiid mite of the family Phytoseiidae belonging to the suborder Gamasidae, a representative example of which is Phytoseiulus swirskii,
The bait mite is at least one species of Astigmatid mite of the family Carbuncleidae, which belongs to the suborder Astigmatidae, of which Carbuncle is a representative example;
The water-retaining material contains feed that has been watered using an aqueous solution containing sugars.
A breeding device for natural enemy insects. The natural enemy insect breeding device according to claim 1, wherein the bait mites further include one type of acarid mite of the Astigmatidae family belonging to the suborder Acaridae, of which Astigmatism is a representative example, and the initial density of the acarid mite is configured to be lower than the initial density of the sugar mite. The natural enemy insect breeding device according to claim 2, wherein the initial density of the sugar mites is 1,000 and the initial density of the astigmatids is 2 to 40. The natural enemy insect breeding device according to claim 1 or 2, wherein the sugar is at least one selected from the group consisting of trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol, and erythritol. The breeding device for natural enemy insects described in claim 1 or 2, wherein the water-retaining material contains food that has been moistened using an aqueous solution containing a substance containing a nitrogen component in addition to the sugars. The natural enemy insect breeding device according to claim 5, wherein the nitrogen-containing substance is at least one selected from the group consisting of urea, peptone, yeast, amino acids, and vitamins. The natural enemy insect breeding device according to claim 1 or 2, wherein the water-retaining material is a granular water-retaining material made of a highly water-absorbent resin, with five particles retaining water and adjusted to a total weight of 4 to 7 g. The natural enemy insect breeding device according to claim 1 or 2, wherein the natural enemy insects further include Gamasid mites of the Gamasidae family belonging to the suborder Gamasida, and the initial density of the Gamasid mites is 1 to 3 per 100 of the one type of phytoseiid mites. A method for propagating phytoseiid mites to improve the number and duration of release of natural enemy insects used in controlling difficult-to-control micro-pests using natural enemy insects, comprising:
3. A method for breeding phytoseiid mites, comprising using the breeding device for natural enemy insects according to claim 1 or 2, and maintaining an increase in the population of phytoseiid mites, which are natural enemy insects, for a long period of time. A method for propagating phytoseiid mites and Gamas mites, which is used when controlling difficult-to-control micro-pest insects using natural enemy insects and involves simultaneously releasing phytoseiid mites and Gamas mites as natural enemy insects, characterized in that the method uses the natural enemy insect propagating device described in claim 8 to increase the population of phytoseiid mites, and then increases the population of Gamas mites after the proliferation of the phytoseiid mites has weakened. A method for controlling difficult-to-control microscopic pests, comprising installing the natural enemy insect breeding device described in claim 1 or 2 in an area where the difficult-to-control microscopic pests live.