JP4890353B2 - Method for preserving insect bodies having the ability to produce fruit bodies of insect parasitic fungi - Google Patents

Description

  The present invention relates to a method for preserving an insect body having the ability to produce fruit bodies (mushrooms) of insect parasitic fungi such as Cordyceps fungus used as health foods, pharmaceuticals, cosmetics and the like.

  Insect parasitic fungi (insect pathogenic fungi) are used as raw materials and high-grade foods for traditional Chinese medicine, such as Cordyceps fungus. Usually, fruit bodies such as Cordyceps fungus are collected in nature, so there are few absolute numbers, they are not uniform in size, and the quality is often not constant. Insect parasitic fungi, even in the same genus species such as sanagitake, usually showed differences in growth rate, fungal growth and pathogenicity. For this reason, search for excellent insect parasites and research on artificial culture methods have been actively conducted.

  For example, a method is known in which a host insect is artificially inoculated with a caterpillar fungus and bred while being temperature-controlled at such a low temperature that the host insect does not develop to obtain a fruiting body (see, for example, Patent Document 1). In this method, inoculation is performed by immersing the host insect moth in a suspension of Cordyceps ascospore spores. However, when this method is performed at room temperature, most of the wrinkles will emerge or bacteria will be remarkably generated, and the probability of obtaining the desired fruiting body is often extremely low. The inoculation method by suspension causes unevenness in infected individuals, and the time until infection is extremely long. On the other hand, when managed at a low temperature, it took a significantly long time to form fruit bodies derived from ascospores.

  In addition, a method has been proposed in which a medium is prepared using an extract of cocoon moth, a fruit body of Cordyceps fungus is formed using this medium, and the ascospores are used (for example, Patent Document 2). reference). In this case, in addition to immersing the cocoon in the ascospore suspension, inoculating the mycelium with the cocoon, and inoculating the ascospore suspension directly into the cocoon, there are also methods. In addition to these methods, an inoculum containing hyphalbodies of insect parasites such as Cordyceps fungus is prepared and introduced by injecting it into the insect body to form fruit bodies using this insect as an insect fungus bed Methods are also known.

  Insect parasites are subcultured by culturing using a medium, and a method of storing cultured mycelia at a low temperature is generally performed. However, no ascospores could be formed even when cultured with hyphalbodies. In addition, any of the above-mentioned production methods of fruiting bodies were carried out as a series of work from the inoculation and infection of insect parasites to the formation of fruiting bodies, which were stopped on the way and could not be put on hold .

As a method for forming a fruit body of an insect parasitic fungus, the present inventors have already proposed a method for infecting an insect parasitic fungus by scratching the epidermis of a host insect (see Patent Document 3). According to this method, infection with insect parasites is fast, hyphae are likely to spread within the insect body, the fruit bodies are well aligned, and stable fruit bodies can be secured. Insect parasites can be stored frozen or refrigerated after ascospores obtained from fruiting bodies are dropped onto the medium.
JP-A-8-75 (Pages 2 and 3) Japanese Patent Application Laid-Open No. 10-42691 (Pages 2, 4, and 5) Japanese Patent No. 3902216 (first page, second page and eighth page)

  By the way, intestinal bacteria and the like originally exist in the insect body, and have the property that aseptic culture is difficult. Even when insects were inoculated with insect parasites such as Cordyceps fungus, it was difficult to go through the entire process aseptically. In particular, the bacteria generated during the isolation of the insect parasites have a high affinity for the insect parasites or are in a symbiotic relationship, and in many cases, it was difficult to sterilize the bacteria. Therefore, it was necessary to form fruit bodies even under such microbial conditions. In addition, when insects are laid eggs and given artificial feed, antibacterial substances are often mixed with the feed, which has prevented infection by insect parasites.

  In general, the period until the fruit body formation of insect parasitic fungi is remarkably long. For example, in order to prevent emergence of the moth Lepidoptera as a lepidopterous insect moth, it is controlled at a temperature of about 10 ° C., so that the insect parasitic fungus spreads in the moth. It took a few months to complete. However, this did not give a prospect until an infected individual was obtained, and it was not only possible to move to the process of generating the next fruiting body, but also to stop during this work process.

  The production methods of fruiting bodies described in Patent Documents 1 and 2 are also performed as a series of non-breaking operations from the inoculation and infection of insect parasites to the formation of fruiting bodies, and can be stopped or interrupted on the way. There wasn't. In addition, in the preservation of mycelia by freezing or refrigeration described in Patent Document 3, it is necessary to set appropriate conditions such as replenishing necessary nutrients to release the freezing or refrigeration to obtain fruit bodies, It was a situation where it was difficult to obtain a desired child entity. Therefore, there has been a demand for a technique that can stop the formation of the fruit body of an insect parasitic fungus and then restart the formation of the fruit body at an appropriate time, thereby efficiently producing the fruit body.

  Accordingly, the object of the present invention is to inoculate and infect insects with insect parasites, stop the formation of fruit bodies of insect parasites for a certain period of time, and then restart the formation of fruit bodies to It is an object of the present invention to provide a method for preserving an insect body having the ability to produce fruit bodies of insect parasitic fungi that can be easily formed and can efficiently produce fruit bodies.

  In order to achieve the above object, the method for preserving an insect body having a fruit body producing ability of an insect parasitic fungus according to claim 1 comprises infecting an insect with an insect parasitic fungus, and infecting and curing the insect body or child. After storing the insect body in which the primordial primordium is formed in a container having a temperature of 20 to 25 ° C. and a relative humidity of 55 to 75%, and pre-drying so that the moisture content of the insect body is 5 to 15%. , Stored under refrigerated or frozen conditions of 0 to 6 ° C.

  The method for preserving an insect body having an ability to produce fruit bodies of an insect parasitic fungus according to claim 2 is the invention according to claim 1, wherein the pre-dried insect body is put into a desiccant filled in a container. The container is characterized in that the relative humidity in the container is maintained at 0 to 55% and then stored under refrigerated or frozen conditions at 0 to 6 ° C.

According to a third aspect of the present invention, there is provided a method for preserving an insect body having a fruit body producing ability of an insect parasitic fungus, wherein the desiccant is silica gel in the invention according to the second aspect.
The method for preserving an insect body having an ability to produce fruit bodies of insect parasitic fungi according to claim 4 is the invention according to any one of claims 1 to 3, wherein a plurality of insect bodies are stored in a container. It is characterized by.

  The method for preserving an insect body having an ability to produce fruit bodies of an insect parasitic fungus according to claim 5 is characterized in that, in the invention according to any one of claims 1 to 4, the insect parasitic fungus is Cordyceps fungus. To do.

According to the present invention, the following effects can be exhibited.
In the invention according to claim 1, an insect body in which an insect parasitic fungus is inoculated to an insect and infected and cured, or an insect body base is formed, the temperature is 20 to 25 ° C. and the relative humidity is 55. Store in a ~ 75% container and pre-dry so that the moisture content of the insect body is 5-15%. Thereafter, the insect body is preserved under refrigerated or frozen conditions of 0 to 6 ° C. For this reason, after the moisture on the surface of the insect body is removed according to the temperature and relative humidity conditions in the container, the moisture inside the insect body gradually moves to the surface and is removed. It becomes a state suitable for the growth and storage of mycelium. Subsequently, the insect body is preserved for a long time without being spoiled by being refrigerated or frozen. Therefore, after inoculating and infecting insect parasitic fungi, the fruiting body of insect parasitic fungi can be stopped for a certain period of time, and then the fruiting body can be restarted to form the fruiting body easily. Entity production can be performed efficiently.

  In the invention according to claim 2, after putting the pre-dried insect body into the desiccant filled in the container, the relative humidity in the container is maintained at 0 to 55%, and then refrigerated at 0 to 6 ° C. Or it preserve | saves on freezing conditions. For this reason, in addition to the effect of the invention according to claim 1, the drying of the insect body can be promoted after the preliminary drying, and the formation rate of the fruiting body can be improved when the formation of the fruiting body is resumed.

In the invention according to claim 3, since the desiccant is silica gel, in addition to the effect of the invention according to claim 2, the drying ability can be easily increased.
In the invention according to claim 4, since a plurality of insect bodies are stored in a container, in addition to the effects of the invention according to any one of claims 1 to 3, a plurality of insect bodies are stored simultaneously. And can improve the productivity of the fruit bodies of insect parasitic fungi.

  In the invention according to claim 5, since the insect parasitic fungus is Cordyceps fungus, the effect of the invention according to any one of Claims 1 to 4 can be exerted on Cordyceps fungus, and its utility value is increased. be able to.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
In this embodiment, the method for preserving an insect body having the ability to produce fruit bodies of insect parasitic fungi is obtained by infecting insects with an insect parasitic fungus and infecting and hardening insect bodies or insect bodies having fruit body primordium formed. After pre-drying, it is stored under refrigerated or frozen conditions. In the preliminary drying, the temperature is 20 to 25 ° C. and the relative humidity (also simply referred to as humidity) is stored in a container having 55 to 75%, and drying is performed so that the moisture content of the insect body is 5 to 15%. Refrigeration is performed on the conditions of 0-6 degreeC. By this preservation method, the fruit body of the insect parasitic fungus is well preserved, and the fruit body can be easily formed when the fruit body formation is resumed.

  The insects are not particularly limited, but lepidopteran insects, Coleoptera insects, and the like are used. Examples of the lepidopteran insect include Lotus moth, tobacco moth, silkworm moth, diamondback moth, bark beetle, bat moth and the like. Examples of Coleoptera insects include scarab beetles, longhorn beetles, and beetles. Here, the term “insect” is a concept including any form (ecology) in the growth process of larvae, pupae, adults, and the like, but the form of pupae is preferable because of ease of handling.

  Examples of insect parasitic fungi include the genus Acantochemis, the genus Giberla, the genus Cordyceps, the genus Stillopera, the genus Tillacridium, the genus Tripocladium, the genus Torviera, the genus Nomuraea, the genus Hymenostyrbe, the genus Hilostella, Examples include fungi such as Pekyromyces, Bobelia and Metalidium. Here, Cordyceps fungus is a fungus that falls under the genus Ascomycota, ergot (Bacaku), and a genus (Cycium genus) of the ergot family. Specific examples of cordyceps fungi are fungi belonging to the genus Cordyceps, Gilbera, Torviera and Hiltella in the ergot family. Examples of Cordyceps fungi include Cordyceps militaris, Usxanagitake and the like.

  The method for inoculating the insects with insect parasites is not particularly limited, but in order to carry out easily and effectively, a method of scratching the insect epidermis is preferable. As the method, it can be carried out using a hard, sharp blade such as a needle, a metal piece, glass or ceramic, or laser light. Insect parasites are inoculated into the wounded part of the insect (hereinafter referred to as the wounded part), so that the infection of the insect parasites is promoted, and the insects are easily propagated in the body of the insects. Cured or fruit body primordium is formed. Here, the fruit body primordium refers to a granular part (bud) that is the basis of the fruit body. When an insect parasite is inoculated into the wounded part of an injured insect, it propagates in the body of the insect, the insect becomes a mycelium, and a fruiting body primordium is formed on the epidermis of the insect.

  For example, using Sanagitake, an insect parasitic fungus, purely cultivates Sanagitake on a PDA medium (Potato Dextrose Agar, potato sugar agar) as an agar medium at 22 ° C. to invade the mycelium. On the other hand, a non-dormant lotus beetle is injured with sharp tweezers, placed on a PDA medium, inoculated with sanagitake, and stored for several days for infection. Thereafter, the movement of the heel stops and can be cured. Insect skin usually has a defense mechanism against parasitic fungi, so it is difficult for the parasitic fungus to infect, but when the insect epidermis is inoculated with mildly injured parts, the speed of infection increases. Parasitic bacteria can be rapidly propagated in the body of insects. As the medium, a grain medium using sticky rice, wheat, barley, or the like can be used.

  In this way, by inoculating insects in a state where mycelia (mycosis) of insect parasitic fungi are formed on the medium, especially in a state where the hyphae are prevalent, the effects of bacteria originally held by the insects can be reduced. It is possible to eliminate and obtain a quick infection of insect parasites. As a result, the infection probability of insect parasites is high, and the yield can be improved.

Next, preliminary drying of the insect body will be described.
The preliminary drying is performed so that the insect body is stored in a container (sealed container) having a temperature of 20 to 25 ° C. and a relative humidity of 55 to 75% so that the moisture content of the insect body is 5 to 15%. . In the preliminary drying, it is desirable to store in a container having the above temperature and relative humidity for 7 to 10 days. By such preliminary drying, moisture or water droplets on the surface of the insect body are removed, and moisture that is moving from the body of the insect to the surface is also removed, so that the body water of the insect body can be lowered. When the temperature is lower than 20 ° C., the temperature is low and the drying efficiency is deteriorated. When the temperature is higher than 25 ° C., the drying progresses faster and the moisture content of the insect body decreases. When the relative humidity is lower than 55%, the drying proceeds fast and the moisture content of the insect body is insufficient. When the relative humidity is higher than 75%, the drying of the insect body is delayed and the moisture content of the insect body becomes excessive. In addition, when the storage period of the insect body in the container is less than 7 days, it is difficult to reduce the moisture content of the insect body, and when it exceeds 10 days, the moisture content of the insect body is excessive. Shows a downward trend. In pre-drying, the moisture content of the insect body is set to 5 to 15%. However, if the insect body is less than 5%, the formation of the desired fruit body is obtained when the formation of the fruit body is resumed after storage of the insect body. It becomes impossible. On the other hand, when it exceeds 15%, the moisture content of the insect body becomes too large, resulting in the decay of the insect body during the preservation of the insect body.

  Moreover, it is desirable to maintain the relative humidity in the container at 0 to 55% after the pre-dried insect body is put into a desiccant filled in the container. In this case, it is preferable to maintain the relative humidity in the container immediately after the insect body is put in the container at 0 to 20%. When the relative humidity in the container exceeds 55%, the insect body decays during storage of the insect body, and the fruit body formation rate of the insect parasitic fungus decreases after refrigeration or frozen storage. Further, when the relative humidity in the container immediately after the insect body is put into the container exceeds 20%, it is difficult to maintain the relative humidity in the container at 55% or less.

By this drying treatment, the moisture content of the insect body can be quickly absorbed to promote drying, and the formation rate of the fruit body can be increased when the formation of the fruit body is resumed. As the desiccant, silica gel (SiO ₂ · nH ₂ O), molecular sieve (molecular sieve), calcium chloride, quicklime, activated alumina and the like are used, and silica gel is used because it can easily increase the drying capacity. preferable. In the drying treatment, a glass container with high airtightness is used, and the desiccant is preferably filled in 60% or more, more preferably 80% or more in the glass container. In this case, the amount of moisture absorbed by the desiccant can be increased. Furthermore, it is desirable to increase the moisture absorption effect of the insect body by drying the insect body in the desiccant during the drying treatment.

  By such an operation, since the desiccant absorbs the water discharged from the insect body, no water droplets are present on the insect body surface. As a result, it is possible to prevent the growth of filamentous fungi and bacteria on the surface of the insect body. For example, if the insect body mass is 15 g against silica gel 100 g, the relative humidity in the container can be kept below 20%, and the maximum relative humidity can be controlled below 55%. It becomes. This method can further exert an effect of assisting refrigeration or freezing storage.

The amount of the desiccant used is preferably 0.1 to 0.13 g / cm ³ as the mass of silica gel per unit volume of the container when silica gel is used as the desiccant. Moreover, in the case of an insect body carrying Cordyceps fungus, the mass of silica gel is preferably 7 to 17 times, more preferably 13 to 17 times the mass of the insect body. If the amount of silica gel used is less than 0.1 g / cm ³ or less than 7 times, the humidity in the container cannot be lowered sufficiently, and it is not easy to reduce the moisture content of the insect body to 15% or less. Absent. On the other hand, when it exceeds 0.13 g / cm ³ or when it exceeds 17 times, the humidity in the container is excessively lowered by excessive silica gel, and there is a possibility that the moisture of the insect body is less than 5%. When the desiccant is put into the container, it can be put as it is, but it is desirable to put it in a net bag or the like. In addition, there is no problem even if a desiccant such as silica gel directly touches the insect body.

  Subsequently, the storage after the preliminary drying is performed by refrigeration or freezing (freezing) at 0 to 6 ° C. The state after preliminary drying is maintained by such storage conditions, and the fruit body production ability can be maintained for a long period of time, for example, 1 year or more, and in the best case, 4 years or more. In the case of refrigeration, if the temperature is higher than 6 ° C., the storage state is poor and the insect body rots. It is preferable that the temperature of refrigeration is 0-2 degreeC. The freezing temperature is preferably less than 0 ° C. and about −70 ° C. or more, more preferably −10 to −30 ° C. Making the freezing temperature lower than −70 ° C. is not realistic because the freezing condition becomes severe.

  When placing an insect body under freezing conditions, it is desirable to use the insect-bearing insect body just before the formation of the fruiting body primordium. When the fruiting body primordium is formed, it tends to be necrotized by freezing. Therefore, when the fruiting body is produced again, the number of fruiting bodies tends to decrease.

  During storage, it is preferable to place the insect body in a container that can produce a large amount of insects and that can be maintained at a low temperature and the humidity can be adjusted. In this method, a mass-produced insect body can be sealed, specifically, put in a glass bottle or a plastic container at the same time as the desiccant, and then stored in a large refrigerator. This method can be maintained until it is used for generating fruit bodies again.

  In order to preserve insects under refrigerated or frozen conditions, it is necessary that there is no growth of fruiting body primordia, and those where fruiting bodies are being formed are damaged or damaged by these preservations, The method is not suitable. The disorder or damage is specifically necrosis of the fruiting body primordial tissue due to freezing, and the damage refers to breakage of the tip or loss from the insect body, and thus growth delay or growth failure. However, it is desirable that the form of the insect body to be subjected to freezing is a state in which the Cordyceps fungus is sufficiently spread in the insect body just before the formation of the fruiting body. In general, 14 to 20 days is a standard for producing an insect body in this state, but it can be determined by the degree of hardening of an insect body in which no fruit body primordium is formed.

  FIG. 1 is an explanatory view schematically showing an insect body storage device having the ability to produce fruit bodies of insect parasitic fungi. As shown in FIG. 1, in a refrigerator or freezer 11, a plurality of (two in FIG. 1) sealed containers 14 that contain a plurality of insect bodies 12 that carry Cordyceps fungus and are covered with lids 13. Is stored. The sealed container 14 is filled with silica gel 15 as a desiccant, and a large number of insect bodies 12 are embedded therein. It is preferable to dry the sealed container 14 in advance. That is, it is preferable that the fine water droplets generated on the surface of the insect body 12 are placed in the sealed container 14 after the insect body 12 is removed by placing it in the air conditioner operating chamber.

  After refrigeration or freezing, the formation of fruiting bodies is resumed by returning to a normal state, for example, by returning to a temperature of 20 to 25 ° C. and a humidity of 30 to 70%, whereby the fruiting body of the desired insect parasitic fungus is easily obtained. Insect bodies have wet surfaces when they are just removed from the refrigerator compartment or freezer compartment, and in order to quickly dry the moisture on the surface, place the sealed container in a sterile room dried with an air conditioner, etc. It is preferable to reduce the humidity by evaporating fine water droplets on the surface of insect bodies carrying Cordyceps fungus. Since drying can be performed quickly by such an operation, the individual quality of the stored insect body can be improved. In addition, since the size of the fruiting body depends on the number of fruiting bodies generated from the insect body, even if one fruiting body is missing, if other fruiting bodies remain, it will hinder the actual production. There is often no. By these methods, it becomes possible to secure a large number of insect bodies with uniform quality, and the effect of being able to produce all at the same time in the formation of fruit bodies is exhibited.

  As described above, in the method for preserving insect bodies having the fruit body production ability of insect parasitic fungi according to this embodiment, hyphae in insect bodies can be stably preserved by optimally combining dry conditions and low temperature conditions. Therefore, the formation rate of the fruiting body after storage is high, and it becomes possible to quickly form the fruiting body. Normally, when an insect parasite fungus mycosis fungus hyphae is artificially propagated and infected with an insect, the insect hardens to form a fruit body primordium, and the insect body continues to form a fruit body. . However, if it becomes necessary to temporarily hold the insect body for the convenience of production, it can be stored for a long period of time, for example one year or more, and further in a good condition by storing it under the refrigerated or frozen conditions. In some cases, it can be stored for more than 4 years. The moisture content in the insect body can be reduced to a certain amount of moisture, that is, the moisture content of the insect body to a level where it can be preserved, and the mycelium can be sufficiently spread. Furthermore, water is discharged when the mycelia of Cordyceps fungus are spread in the insect body, but the water is absorbed by the drying conditions, and this process can be carried out smoothly.

  This means that the fruit body of Cordyceps can be artificially controlled and the production of fruit bodies can be delayed. In other words, it makes it possible to control the production of Cordyceps sinensis fruit bodies by insect bodies carrying Cordyceps fungus. An actual insect grows due to an increase in temperature, and when it reaches a specific predetermined integrated temperature, it proceeds to the stage of hatching from larvae or hatching from hatching. In order to control this and retain Cordyceps fungus to produce fruit bodies, it is necessary to produce fruit bodies according to the amount of insects produced. The production of Cordyceps fungus fruit bodies can be implemented systematically in the form of insect stock.

According to the embodiment described above in detail, the following operations and effects are exhibited.
-Insect parasites are inoculated into insects in this embodiment, and infected insect bodies or insect bodies in which fruit body primordia are formed have a temperature of 20 to 25 ° C and a relative humidity of 55 to 75%. Store in a container and perform preliminary drying so that the moisture content of the insect body is 5-15%. Thereafter, the insect body is preserved under refrigerated or frozen conditions of 0 to 6 ° C. For this reason, after the moisture on the surface of the insect body is removed according to the temperature and relative humidity conditions in the container, the moisture inside the insect body gradually moves to the surface and is removed. It becomes a state suitable for the growth and storage of mycelium. Subsequently, the insect body is preserved for a long time without being spoiled by being refrigerated or frozen.

  Therefore, after inoculating and infecting insect parasitic fungi, the fruiting body of insect parasitic fungi can be stopped for a certain period of time, and then the fruiting body can be restarted to form the fruiting body easily. Entity production can be performed efficiently. That is, it is possible to enter a work process in which a series of work processes such as infection of insect parasites to insects and formation of fruiting bodies are stopped halfway to preserve insect bodies and form fruiting bodies again. In other words, it becomes possible to arrange the insect parasite infection time on the insect body, control the production of the fruit body of the insect parasite, and adjust the production of the fruit body. It can be stored, managed, and transferred to the fruit production process when the necessary number of individuals has been secured.

  -After the pre-dried insect body is put into a desiccant filled in a container, the relative humidity in the container is maintained at 0 to 55%, and then stored under refrigerated or frozen conditions at 0 to 6 ° C. It is preferable. In this case, drying of the insect body can be promoted after preliminary drying, and the formation rate of the fruit body can be improved when the formation of the fruit body is resumed.

-Since the said desiccant is a silica gel, a drying capability can be improved easily.
-By storing a plurality of insect bodies in a container, a plurality of insect bodies can be stored at the same time, and productivity of fruit bodies of insect parasitic fungi can be improved.

  -When the insect parasitic fungus is Cordyceps fungus, the above-mentioned effects can be exhibited and the utility value can be increased.

Hereinafter, although the embodiment will be described more specifically with reference examples and examples, the present invention is not limited to the scope of these examples.
(Reference Examples 1 to 4 and Examples 1 and 2, fruit body formation test by difference in storage conditions)
Insect parasites (Cordyceps militalis), which mainly consist of Cordyceps sinensis fungi, were artificially bred with mycelia, and all of the following tests were done with Lotus moth. Infected and cured insect bodies or insect bodies in which insect bodies hardened to form fruit body primordium were used. In Reference Example 1 (drying only), this insect body is placed in a drying room having a relative humidity of 80, 60, 50, 40, 30, 20, and 10% or less as a drying condition, and is periodically removed to form a fruiting body. I investigated. In Reference Example 2 (only refrigeration), the insect body was placed in a refrigerator at 0 to 2 ° C., 4 to 6 ° C., and 8 ° C. as refrigeration conditions, and periodically removed to examine the formation state of fruit bodies. In Reference Example 3 (freezing only), the insect body was placed in a freezer at -1, -10 and -70 ° C as freezing conditions, and removed periodically to examine the formation state of fruiting bodies. As Reference Example 4, the formation state of fruiting bodies was examined for insect bodies that were not treated.

  In Examples 1 and 2, as pre-drying, the insect body was stored in a container at a temperature of 20 ° C. and a relative humidity of 60% for 10 days, and the moisture content of the insect body was 10% (the moisture reduction rate in the insect body was 90%). %). In Example 1, the pre-dried insect body was refrigerated at a temperature of 2 ° C. In Example 2, the pre-dried insect body was stored frozen at -20 ° C. During the storage period, it was taken out periodically and returned to the normal state (temperature 25 ° C., humidity 50%, the same applies hereinafter), and the formation state of the fruiting bodies was examined. The results are shown in Table 1. In addition, for the test, insect bodies carrying 10 individuals of Cordyceps fungus in each group were used.

表１に示した結果より、参考例１においては、湿度８０、６０、５０、４０、３０、２０及び１０％以下の恒湿度室で保存した昆虫体の発芽は、湿度８０％では形成されなかった。湿度６０％では1ヶ月後に子実体が一部形成された。湿度５０％と４０％区では２ヶ月以上安定して１個体から１〜３本以上の子実体が安定して形成された。しかし、３ヶ月を経過すると発生する子実体が０本となるものも発生し、安定しなくなった。湿度３０％、２０％及び１０％以下の条件では３ヶ月間安定して子実体の形成が認められたが、４ヶ月以降はやや不安定となった。従って、湿度の低下に伴って保存の安定化を助長できることが判明した。

From the results shown in Table 1, in Reference Example 1, germination of insect bodies stored in a constant humidity room at a humidity of 80, 60, 50, 40, 30, 20, and 10% or less is not formed at a humidity of 80%. It was. At 60% humidity, some fruiting bodies were formed after one month. In the 50% and 40% humidity groups, 1 to 3 or more fruiting bodies were stably formed from 1 to 2 months. However, after 3 months, there were also cases where the number of fruiting bodies was zero, which became unstable. Under the conditions of humidity of 30%, 20% and 10% or less, the formation of fruit bodies was recognized stably for 3 months, but after 4 months it became slightly unstable. Therefore, it has been found that stabilization of storage can be promoted with a decrease in humidity.

  In Reference Example 2, formation of fruit bodies was observed after 6 months in insect bodies stored at 0 to 2 ° C., and formation of fruit bodies was observed after 3 months in insect bodies stored at 4 to 6 ° C. However, when stored refrigerated at 8 ° C., formation of fruiting bodies was observed for 2 months, but formation of fruiting bodies was not observed after 3 months. As a result, it was found that if it is 2 ° C. or lower, the storage can be stably performed over a long period of 6 months or longer.

  In Reference Example 3, formation of fruiting bodies was observed in insect bodies stored at -1, -10, -20 and -70 ° C for 6 months. In addition, insect bodies stored at −70 ° C. showed good formation of fruit bodies after 24 months, and formation of fruit bodies was observed after 40 months. As a result, it was found that refrigeration can withstand long-term storage rather than refrigeration.

In Reference Example 4, the formation of fruit bodies was not recognized in about one month without treatment.
In Example 1, the insect body up to 18 months later stably forms 1 to 3 fruiting bodies from the insect body, and when one fruiting body is formed, it becomes a relatively large fruiting body. It was. After 18 months, it was slightly more unstable than before, but the formation of fruiting bodies was observed from the insect body until 27 months later. As a result, it has been found that a combination of pre-drying and refrigeration can be stored in a stable state for a long period of time.

In Example 2, formation of fruiting bodies was recognized stably for 48 months. Therefore, it has become clear that a method of freezing after pre-drying is suitable for long-term storage.
(Example 3, relationship between formation of fruit body primordium and refrigeration and frozen storage)
Whether or not the fruiting body primordia were formed during the preservation of the insect body and whether the fruiting body formation after freezing was affected or not was examined. Twenty insect bodies with no fruiting body primordium and 20 insect bodies with a fruiting body primordium having a size of 1 mm or more were dried and frozen (−70 ° C.) and stored at a humidity of 10%. It was stored after drying and refrigeration (2 ° C.), and after 3 months, the state of the fruiting body primordium was examined and taken out to examine the formation of fruiting bodies under normal conditions.

As a result, when the refrigeration treatment was performed after the preliminary drying, there was no difference in the formation of the fruit bodies regardless of the formation of the fruit body primordium, and from one to several fruit bodies were formed. On the other hand, when the freezing treatment was performed after the pre-drying, when the fruit body primordium was 1 mm or more, the tissue was necrotized and the fruit body formation was poor. However, even if this fruiting body was necrotic, a fruiting body was formed from a slightly recognized fruiting body primordium, and in the case of one, it grew into a relatively large fruiting body. Such a result was the same also in refrigeration after preliminary drying. From these results, it was found that the insect body is suitable for preserving the insect body until just before the formation of the fruit body primordia.
(Example 4, fruit body formation test by processing conditions of desiccant)
Create a section containing 50, 100, 200, 300, 400, and 500 g of silica gel in a closed storage container (20 cm long, 20 cm wide and 10 cm high), and simultaneously put 300 insect bodies that have finished preliminary drying. The change of humidity was examined. Since the 400 and 500 g sections were large in quantity, insect bodies were buried in silica gel. Thereafter, insect bodies were stored in a freezer at a temperature of −20 ° C., periodically taken out and returned to a normal state, fruit bodies were formed, and the formation rate was examined.

  As a result, in the 50 and 100 g sections, the humidity decreased temporarily, but when the moisture was discharged from the insect body, the humidity reached 70% or more, and it became clear that the amount of silica gel was small. In the 200 g section, the humidity temporarily decreased to about 20% and then increased to about 55%. In the 300 g section, the humidity decreased to about 10% and then increased to 40-50%. In the 400 and 500 g sections, the humidity quickly reached 10% or less and then gradually increased to about 40%. As a result of taking out these insect bodies and examining the formation of fruit bodies, the fruit body formation rate was stably 80% or more in the 400 to 500 g section. There were also no rotting insect bodies.

Therefore, silica gel per volume of the vessel is found to 400 to 500 g / 4000 cm ^3, i.e. silica gel of 0.1~0.125g / cm ³ are suitable. Furthermore, since one insect body is about 0.1 g, the mass of the silica gel is (400 to 500) / (300 × 0.1) = 13.3 to 16.7, relative to the mass of the insect body. That is, 13 to 17 times was found to be appropriate.
(Reference Example 5, pre-drying of insect body carrying Cordyceps fungus)
The Spodoptera litura, which has begun to become infected with Cordyceps sinensis, is stored at 15, 18, 20, 23, 25 and 27 ° C in a relative humidity of 50, 60, 70, 80 and 90% for 10 days. , Remove the moisture on the surface of the insect body, reduce the moisture in the body, weigh the moth and measure the amount of water loss (%), then moisturize to form the fruiting body (%) It was measured. The amount of water loss (%) of insect bodies is shown in Table 2, and the fruit body formation rate (%) is shown in Table 3. In addition, the moisture reduction rate of the insect body was calculated by measuring the absolute amount of moisture of the insect body by mummifying the insect body.

表２に示した結果より、昆虫体の水分減少量（％）は温度２０〜２５℃、湿度６０〜７０％で９５〜８５％減少した（昆虫体中の水分量は５〜１５％）。また、表３に示した結果より、前記条件下での子実体形成率も８９〜９１％と高かった。一方、湿度が８０％以上、又は温度が２７℃では腐敗個体が増加した。この結果、冬虫夏草菌が感染して硬化しはじめたハスモンヨトウの蛹は所定の予備乾燥を行うことにより菌糸が蔓延して水分が排出され、腐敗が少なくなり、子実体の形成率が高まることが判明した。
（実施例５、６及び参考例６、乾燥処理による水分除去）
冬虫夏草菌を主とする昆虫寄生菌（サナギタケ）の菌糸を人工的に繁殖させてハスモンヨトウ蛹に感染させ、硬化させた昆虫体を用いた。予備乾燥として、昆虫体を温度２０℃、相対湿度６０％とした容器内に１０日間保存し、昆虫体の水分量を１０％（昆虫体中の水分減少率が９０％）とした。予備乾燥した昆虫体を、ガラス容器（１０００ｍｌ）に充填されたシリカゲル１０、５０、１００、２００、３００及び４００ｇにそれぞれ投入した。そして、参考例６では、常温（２５℃）で保存、実施例５では４〜６℃の冷蔵庫内で冷蔵保存、及び実施例６では−２０℃の冷凍庫内で冷凍保存し、定期的に昆虫体を取り出して常態に戻し、子実体の形成状態を調べた。それらの結果を表４に示した。

From the results shown in Table 2, the water loss (%) of the insect body was reduced by 95 to 85% at a temperature of 20 to 25 ° C. and a humidity of 60 to 70% (the water content in the insect body was 5 to 15%). Moreover, from the results shown in Table 3, the fruiting body formation rate under the above conditions was as high as 89 to 91%. On the other hand, when the humidity was 80% or more or the temperature was 27 ° C., the number of spoilage individuals increased. As a result, it became clear that the moths of Spodoptera litura, which began to infect with Cordyceps sinensis, spread the hyphae and drain water by performing the prescribed preliminary drying, resulting in less spoilage and higher fruit body formation rate. did.
(Examples 5 and 6 and Reference Example 6, water removal by drying treatment)
Insect bodies that were artificially propagated by hyphae of insect parasites (Sanagitake), mainly Cordyceps fungus, were infected with Spodoptera litura and cured. As pre-drying, the insect body was stored in a container at a temperature of 20 ° C. and a relative humidity of 60% for 10 days, and the moisture content of the insect body was 10% (the moisture reduction rate in the insect body was 90%). The pre-dried insect body was put into silica gel 10, 50, 100, 200, 300 and 400 g filled in a glass container (1000 ml), respectively. In Reference Example 6, stored at room temperature (25 ° C.), in Example 5, refrigerated in a refrigerator at 4-6 ° C., and in Example 6, stored in a freezer at −20 ° C. The body was removed and returned to normal, and the formation of the fruiting bodies was examined. The results are shown in Table 4.

上記の結果、蛹を入れる前の容器内の相対湿度は０〜２０％の範囲で推移した。その後、蛹を容器内に入れると湿度は０〜７０％の範囲で推移した。シリカゲルが２００ｇを越すと湿度は５５％以下で推移し、１０ｇでは７０％まで上昇した。１０ｇの区では蛹の腐敗が起こり、水分を十分除去することができなかった。しかし、湿度が５５％以下で推移すると腐敗はなくなった。このことから、蛹を容器内に入れるときの湿度は０〜２０％で、その後の相対湿度は０〜５５％に保持されと腐敗は生じないことが判明した。

As a result of the above, the relative humidity in the container before the soot was put in a range of 0 to 20%. After that, when the bag was placed in the container, the humidity changed in the range of 0 to 70%. When the silica gel exceeded 200 g, the humidity was maintained at 55% or less, and at 10 g, the humidity increased to 70%. In the 10 g section, spoilage of sputum occurred and water could not be removed sufficiently. However, when the humidity remained below 55%, the rot disappeared. From this, it was found that the humidity when the cocoon was put in the container was 0 to 20%, and the relative humidity thereafter was kept at 0 to 55%, and no rot occurred.

  Further, from the results shown in Table 4, when stored at room temperature in Reference Example 6, formation of the fruiting body was poor or no fruiting body was formed. On the other hand, when the refrigerated storage of Example 5 was performed, the formation of fruit bodies was good when the silica gel was 300 g or 400 g and the storage period was up to 12 months. When cryopreserved in Example 6, the formation of fruit bodies was good when the silica gel was 300 g or 400 g and the storage period was up to 48 months.

It should be noted that the embodiment described above can be modified and embodied as follows.
-As the said container, the container provided with the apparatus which can ensure a constant temperature and humidity state automatically can be used, and drying, such as preliminary drying, can also be performed automatically.

-Each insect solid can be divided into containers and accommodated with the desiccant necessary for each solid so that the moisture content of each insect body can be quickly reduced to 5-15%.
・ It is also possible to set conditions for pre-drying insect bodies according to the degree of insect infection by insect parasites.

-It is also possible to measure the moisture content (or moisture reduction amount) of the insect body during preliminary drying, and to change the preliminary drying conditions to shorten the preliminary drying period.
Next, the technical idea that can be grasped from the embodiment will be described below.

  The said insect body is stored for 7 to 10 days in a container having a temperature of 20 to 25 ° C and a relative humidity of 55 to 75%, according to any one of claims 1 to 5. A method for preserving insect bodies having the ability to produce fruit bodies of insect parasitic fungi. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 1-5, the moisture content of an insect body can be easily made into 5 to 15% by preliminary drying.

  The insect parasite fungus according to any one of claims 2 to 5, wherein the relative humidity in the container immediately after the insect body is put in the container is maintained at 0 to 20%. A method for preserving insect bodies having an entity-producing ability. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 2-5, the relative humidity in a container can be easily maintained at 0-55%.

  The insect according to any one of claims 2 to 5, wherein the insect body is put into a desiccant filled in a container so that the insect body is buried. A method for preserving insect bodies having the ability to produce fruit bodies of parasitic fungi. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 2-5, the water | moisture content which transfers to the surface from an insect body can be absorbed effectively.

Explanatory drawing which shows typically the preservation | save apparatus of the insect body which has the fruit body production ability of an insect parasitic fungus.

Explanation of symbols

  12 ... Insect body, 14 ... Sealed container as container, 15 ... Silica gel as desiccant.

Claims (5)

Insect parasites are inoculated into insects, and infected and cured insect bodies or insect body primordial primordial bodies are stored in a container having a temperature of 20 to 25 ° C. and a relative humidity of 55 to 75%. Insect body having the ability to produce fruit bodies of insect parasites, characterized by being pre-dried so that the moisture content of the insect body is 5 to 15% and then stored under refrigerated or frozen conditions at 0 to 6 ° C. How to save. After the pre-dried insect body is put into a desiccant filled in a container, the relative humidity in the container is maintained at 0 to 55%, and then stored under refrigerated or frozen conditions of 0 to 6 ° C. The method for preserving an insect body having an ability to produce fruit bodies of an insect parasitic fungus according to claim 1. The method for preserving an insect body having an ability to produce fruit bodies of insect parasitic fungi according to claim 2, wherein the desiccant is silica gel. The method for preserving an insect body having a fruit body producing ability of an insect parasitic fungus according to any one of claims 1 to 3, wherein a plurality of the insect bodies are stored in a container. The method for preserving an insect body having a fruit body production ability of an insect parasitic fungus according to any one of claims 1 to 4, wherein the insect parasitic fungus is a Cordyceps fungus.

Images