Silverfish Behavior Control Method and Silk Spinning Position Control Method

Abstract

Developed and provided are a behavior control method for bagworms and a spinning position control method which induce bagworms to a predetermined position and cause the bagworms to spin scaffold silk threads at the predetermined position.　Provided are a behavior control method for irradiating the bagworms with light and inducing the bagworms into the light radiation direction, and a spinning position control method for irradiating the bagworms with light at a spinning position on a base material surface and inducing the spinning of bagworms at the position.

Description

Technical Field

[0001] The present invention relates to a method for controlling the behavior of bagworms or a method for controlling the silk-spinning position, and a bagworm silk reeling device using the method.

Background Art

[0002] Bagworms are the general name for the larvae of moths belonging to the family Psychidae of the order Lepidoptera. It is generally known that they live in a spindle-shaped or cylindrical nest (Bag nest) woven with leaves and twigs using silk they spin themselves, and move around with the nest even when feeding, living with the nest throughout the entire larval stage. The bagworm silk spun by these bagworms has recently attracted attention as a very useful novel animal-derived natural fiber.

[0003] However, there are several problems that must be solved before such bagworm silk can be put into practical use. One of them is that it is impossible to obtain long bagworm silk. Since bagworms pupate inside the nest where they lived during the larval stage, they do not perform a cocoon-making behavior again before pupation. In addition, since the nests of bagworms are generally enlarged as they grow from the first instar, the nests contain a mixture of old and new silk threads, and these silk threads are fragmented and discontinuous inside the nest. That is, since the bagworm nest itself is composed of relatively short silk threads intertwined, it is impossible to obtain long fibers from the nest by ordinary methods, and therefore, it has been difficult to put bagworm silk into practical use until now.

[0004] This problem is currently solved by a method of collecting the scaffold silk of the bagworm silk developed by the present inventors in a long state (Patent Document 1). The scaffold silk is the bagworm silk that the bagworm spins in advance in the traveling direction as a foothold to prevent it from falling from a branch or the like. The scaffold silk is spun in a zigzag pattern, and since it is difficult to control the behavior of the bagworm itself and its movement is left to the worm, the bagworm silk is complicatedly overlapped several times by the movement of the bagworm. Conventionally, it has been difficult to collect it. In the above-mentioned silk collection method, by arranging the bagworms on a linear path having a specific width, the behavior of the bagworms is controlled, and successful mass production of long bagworm silk has been achieved. However, when the bagworm silk is spun at a predetermined position on the surface of a three-dimensional structure other than the linear path, there is still no method of guiding the bagworms to the predetermined position and spinning the silk. For the above reasons, in the practical application of bagworm silk, it is urgent to establish a method for controlling the behavior of bagworms.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to develop and provide a method for controlling the behavior of bagworms. Another object is to develop and provide a method for efficiently obtaining bagworm silk.

Means for Solving the Problem

[0008] In order to solve the above problems, as a result of intensive research by the present inventors, it has been found that when a silverfish is irradiated with light, the silverfish has the property of moving in the direction in which the light is radiated, that is, the silverfish has phototaxis. If the radiation direction of the light is changed, the silverfish will change its direction to the new light radiation direction after the change. It has been clarified that such phototaxis acts strongly with light of a specific wavelength. On the other hand, it has also been found that the spinning behavior of silverfish is attracted by light of a wavelength different from that of light with high phototaxis, which has never been known before. By utilizing these characteristics, it becomes possible to freely control the behavior of silverfish, which has been difficult heretofore, and to cause the silverfish to spin at a desired position. The present invention is based on such new findings and provides the following.

[0009] (1) A method for controlling the behavior of a silverfish, comprising the step of irradiating the silverfish with behavior control light and inducing the silverfish in the light radiation direction. (2) The behavior control method according to (1), wherein the wavelength of the behavior control light is 405 nm ± 60 nm. (3) The behavior control method according to (1) or (2), comprising the step of changing the induction direction of the silverfish by changing the light radiation direction. (4) The behavior control method according to any one of (1) to (3), which is performed under light-shielding conditions. (5) A method for controlling the spinning position of a silverfish, comprising the step of irradiating the silverfish with spinning position control light from a predetermined position on a substrate and causing the silverfish to spin at that position. (6) The spinning position control method according to (5), wherein the wavelength of the spinning position control light is 560 nm ± 150 nm. (7) The spinning position control method according to (5) or (6), comprising the step of irradiating the silverfish with behavior control light having a wavelength of 405 nm ± 60 nm from a predetermined position on the substrate and inducing the silverfish to that position. (8) The spinning position control method according to any one of (5) to (7), which is performed under light-shielding conditions. (9) The method for controlling the spinning position according to any one of (5) to (8), wherein the base material is a three-dimensional structure. (10) The method for controlling the spinning position according to any one of (5) to (9), wherein the base material is a transparent base material or a translucent base material. (11) A method for producing a yarn mass of silkworm silk obtained by using the method for controlling the spinning position of silkworms according to any one of (5) to (10). (12) A silkworm silk reeling device comprising one or more light sources capable of emitting spinning position control light from an arbitrary direction to a base material for silkworms to spin on. (13) The device according to (12), wherein the wavelength of the spinning position control light is 560 nm ± 150 nm. (14) The device according to (12) or (13), further comprising one or more light sources capable of emitting behavior control light with a wavelength of 405 nm ± 60 nm from an arbitrary direction to the base material. (15) The device according to any one of (12) to (14), wherein the light source is movable. (16) The device according to any one of (12) to (15), comprising a housing having a light-shielded environment inside. (17) Use of a light source capable of emitting light in the range of 405 nm ± 60 nm for controlling the behavior of silkworms. (18) Use of a light source capable of emitting light in the range of 560 nm ± 150 nm for controlling the spinning position of silkworms. This specification incorporates the disclosure of Japanese Patent Application No. 2020-164314, which is the basis of the priority of this application. [[Effect of the Invention]]

[0010] According to the method for controlling the behavior of silkworms of the present invention, silkworms can be induced to a predetermined position.

[0011] According to the method for controlling the spinning position of silkworms of the present invention, a scaffold silk can be spun onto silkworms at a predetermined position, and silkworm silk can be efficiently obtained.

[0012] According to the silkworm silk reeling device of the present invention, the method for controlling the spinning position of silkworms of the present invention can be realized.

Brief Description of the Drawings

[0013]

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Modes for Carrying Out the Invention

[0014] 1. Method for Controlling the Behavior of Mealworms 1-1. Overview The first aspect of the present invention is a method for controlling the behavior of mealworms. According to the method of the present invention, by irradiating mealworms with light and changing the direction in which the light is emitted, the movement and direction of the mealworms can be freely controlled, and thus, mealworm silk can be efficiently obtained.

[0015] 1-2. Definitions of Terms The following terms frequently used in this specification are defined as follows. As described above, the term "bagworm" refers to the general name for the larvae of moths belonging to the family Psychidae of the order Lepidoptera. Moths of the family Psychidae are distributed worldwide. However, all larvae (bagworms) throughout their entire larval stage sew natural materials such as leaf pieces and twig pieces with silk spun by themselves and live in a nest wrapped with them. Also, all species have the habit of advancing while spinning a foothold silk that serves as a fall prevention foothold in the direction of travel when moving. Therefore, the bagworms used in this specification are the larvae of moths belonging to the family Psychidae, and regardless of the type, age, and sex, as long as they have the above habit. For example, the family Psychidae includes genera such as Acanthopsyche, Anatolopsyche, Bacotia, Bambalina, Canephora, Chalioides, Dahlica, Diplodoma, Eumeta, Eumasia, Kozhantshikovia, Mahasena, Nipponopsyche, Paranarychia, Proutia, Psyche, Pteroma, Siederia, Striglocyrbasia, Taleporia, Theriodopteryx, Trigonodoma, etc. However, the bagworms used in this specification may be species belonging to any genus. Also, the age of the larvae may be any age from the first instar to the last instar. However, when the purpose is to obtain bagworm silk, larger bagworms are preferred. For example, among the same species, the last instar larvae are more preferred, and among males and females, the larger females are more preferred. Also, within the family Psychidae, larger species are more preferred. For example, the large species Eumeta japonica and Eumeta minuscula are suitable as the species used in the present invention. Bagworms are, in principle, bagworms that hold a nest. "Holding a nest" means a state in which a bagworm carries a nest. As described above, bagworms usually live together with their own nests. Even during feeding or moving, only a part of the body is exposed outside the nest, and the whole body is never exposed from the nest throughout the entire larval stage. On the other hand, bagworms in a naked state that are artificially separated from the nest and have their entire body exposed to the outside world may not necessarily conform to the behavior control method of the present invention because they prioritize reconstructing the nest.

[0016] As used herein, the term "silkworm silk" refers to the silk spun by silkworms. In this specification, unless otherwise specified, the term "silk" alone shall refer to silkworm silk. Silkworm silk includes single fibers, spun fibers, and aggregate fibers. A "single fiber" is the smallest unit filament that constitutes a fiber component and is also called a monofilament. Single fibers are mainly composed of fibroin protein. In a natural state, silkworm silk is spun in the form of a b-filament in which two single fibers are bonded by the sericin protein, an adhesive substance. This b-filament is called a "spun fiber". A silkworm's nest is composed of spun fibers. Also, a bundle of multiple spun fibers joined together to form a single fiber bundle is called an "aggregate fiber (multifilament)". Generally, raw silk corresponds to this aggregate fiber.

[0017] There are two types of silkworm silk: support silk and nest silk. "Support silk" is the silk spun by silkworms for movement as described above and has the function of serving as a support (a foothold) to prevent falling from branches, leaves, etc. On the other hand, "nest silk" is the silk spun for constructing a nest, such as for stitching leaf pieces or branch pieces, or for making the inner wall of the nest, which is the living area, a comfortable environment, using silkworm silk. The silkworm silk in the present invention is targeted at support silk for its purpose. Therefore, in this specification, unless otherwise specified, when the term "silkworm silk" is used, it shall refer to support silk.

[0018] As used herein, the term "yarn mass" refers to an aggregate of yarns composed only of the support silk of silkworms. The state of the yarn mass is not limited. For example, it may be a sheet-like form like a non-woven fabric in which one or more silkworm silk yarns are intricately intertwined. Also, the yarn mass may have not only a two-dimensional shape but also a three-dimensional shape with a three-dimensional structure.

[0019] As used herein, the term "substrate" refers to a substrate for collecting silkworm silk. By placing and moving silkworms on this substrate, silkworm silk is spun on its surface. After spinning, the support silk of silkworms can be collected by recovering the silkworm silk on the substrate surface.

[0020] In this specification, "induction" means artificially guiding a living organism to a specific substance or location by utilizing the organism's instinctive behavior or the like.

[0021] In this specification, "behavior control" means freely manipulating the behavior of a silkworm larva, that is, movements such as movement and direction change.

[0022] In this specification, "spinning position control" means freely manipulating the spinning behavior so that a silkworm larva spins the scaffold silk at a predetermined position when spinning the scaffold silk.

[0023] In this specification, "light" mainly refers to artificial light radiated from a light source. When simply denoted as "light" in this specification, it can include any light regardless of the wavelength range or the like. For example, it includes both the aforementioned behavior control light and spinning position control light.

[0024] In this specification, "behavior control light" refers to light having a wavelength that has an attracting effect on a silkworm larva. Also, in this specification, "spinning position control light" refers to light having a wavelength that suppresses the movement of a silkworm larva and causes it to spin the scaffold silk at a specific position.

[0025] In this specification, "wavelength light" refers to light having a predetermined wavelength. Therefore, in the case of wavelength light, unlike when simply denoted as light, the wavelength range of the light is limited to a certain extent. However, the range does not need to be specific.

[0026] In this specification, "light having a peak wavelength" refers to wavelength light having a peak wavelength.

[0027] In this specification, "peak wavelength" refers to the wavelength when the wavelength of the irradiated light shows a mountain shape and its light intensity reaches a maximum value (peak), as shown by a to h in FIG. 2. Also, the light at this time, that is, the wavelength light at the peak wavelength, is often denoted as "peak light" in this specification.

[0028] 1-3. Method The method of this aspect includes an induction step, which is an essential step, and a direction control step, which is a selection step. Hereinafter, each step will be specifically described.

[0029] 1-3-1. Induction step The "induction step" is a step of irradiating the pillbug with action control light to induce the pillbug in the light emission direction. This step utilizes the phototaxis of the pillbug moving towards the light emission direction.

[0030] The action control light may be light of a wavelength at which the pillbug exhibits positive phototaxis, and the wavelength and light intensity are not particularly limited. When inducing the pillbug in the light emission direction more efficiently, it is preferable to irradiate specific wavelength light as the action control light.

[0031] The "specific wavelength light" in this step (often referred to as "specific wavelength light" in this specification) refers to light of a wavelength with a high attracting effect on the pillbug in the case of action control light. Specifically, wavelength light in the range of 405 nm ± 60 nm (345 nm or more and 465 nm or less), 405 nm ± 55 nm (350 nm or more and 460 nm or less), or 405 nm ± 50 nm (355 nm or more and 455 nm or less) is applicable. Preferably, it is wavelength light having a peak wavelength within that wavelength range. As shown in Example 1 described later, the wavelength light in this range has a strong attracting effect on the pillbug compared to other wavelength lights.

[0032] When the specific wavelength light has a peak wavelength, it may be either monochromatic light having one peak wavelength within the specific wavelength range or composite light having a plurality of peak wavelengths within the wavelength range. Preferably, it is monochromatic light.

[0033] "Irradiating the silverfish with light" means irradiating the silverfish with light having a wavelength in the range of 405 nm ± 60 nm, 405 nm ± 55 nm, or 405 nm ± 50 nm, provided that the light is arbitrary wavelength light, for example, behavior control light. Even for light without a peak wavelength such as the light of a fluorescent lamp, only the light having a wavelength within the above range can be selectively transmitted through a wavelength selection filter, and the transmitted wavelength light can be irradiated as specific wavelength light. Note that "irradiating the silverfish" means directly exposing the eye of the silverfish that receives light or the head having the eye to light.

[0034] "Light emission direction" means the direction in which light is emitted. For example, in the case of direct irradiation described later, the direction in which the light source is installed corresponds, and in the case of indirect irradiation, the direction of the reflection surface of the reflector corresponds.

[0035] Continuous irradiation is preferred for irradiating the silverfish with light, but it may also be pulsed light that repeats light and dark periods extremely briefly like a fluorescent lamp, or intermittent irradiation in which a dark period (for example, a dark period of 1 second or more, preferably several seconds) that can be recognized by the naked eye periodically or aperiodically during the irradiation period is inserted.

[0036] The method of irradiating an object with light is not particularly limited as long as it can irradiate the target silverfish with light. For example, either direct irradiation or indirect irradiation may be used. Direct irradiation means irradiating the silverfish directly with the light emitted from the light source. In direct irradiation, the light source may be directed toward the silverfish to irradiate it with light. In the case of direct irradiation, the silverfish moves in the direction in which the light source is arranged. Indirect irradiation means irradiating the silverfish with the reflected light after reflecting the light emitted from the light source without directly irradiating the silverfish with the light, for example, using a reflector such as a mirror. In the case of indirect irradiation, the light emitted from the light source may be reflected by a reflector such as a mirror and directed toward the silverfish to irradiate it with light. Indirect irradiation may be performed through multiple reflections by a plurality of reflectors. In indirect irradiation, care should be taken to ensure that the reflected light irradiating the silverfish becomes the specific wavelength light. Indirect irradiation is particularly useful when the light source is fixed and the silverfish must be irradiated with light from a specific direction.

[0037] The irradiation time for the silkworm moths is not particularly limited. When guiding the silkworm moths to a predetermined position, the above-mentioned behavior control light may be irradiated on the silkworm moths. Usually, after the silkworm moths have finished moving to the predetermined position, further irradiation of the behavior control light is not required. On the other hand, when the silkworm moths are to be detained around the position after moving to the predetermined position and the silkworm moths are actively made to spin silk at that position, as described in the second aspect to be described later, the irradiation of the silk-spinning position control light on the silkworm moths may be continuously carried out at that position.

[0038] In this step, the number of silkworm moths processed by one-time light irradiation is not particularly limited. The type, number of individuals, and / or age of the silkworm moths placed as long as they are within the irradiation range of the light are not questioned. When arranging multiple individuals, for example, all individuals may be of the same species and / or the same age, or some groups of individuals may be of the same species and / or the same age.

[0039] In this step, since the silkworm moths can be guided in a predetermined direction, it can be utilized not only for the purpose of silk collection but also, for example, when feeding the silkworm moths in a breeding environment, when efficiently moving them from an old feeding place to a new feeding place.

[0040] 1-3-2. Direction Control Step The "direction control step" is a step of changing the traveling direction of the silkworm moths by changing the light emission direction. As described above, when the silkworm moths are irradiated with light, the silkworm moths move toward the light emission direction. Even during the movement, if the light emission direction moves, the traveling direction also changes in accordance with the movement. Thereby, the direction in which the silkworm moths move can be freely controlled.

[0041] The means for changing the light emission direction is not particularly limited. In the case of direct irradiation, the light source may be arranged in a new direction in which the silkworm moths are to be moved. If the light source cannot be moved, the substrate itself may be moved so that the substrate on which the silkworm moths are arranged faces the light source in a predetermined direction. In the case of indirect irradiation, the reflector may be moved and / or rotated, and the number thereof may be increased or decreased as necessary so that the silkworm moths can be irradiated with light from a predetermined position on the substrate.

[0042] The light emission direction is not limited. The predetermined direction in which the silkworm moths should be induced becomes the light emission direction. Also, the change in the light emission direction is not limited to once, and can be performed multiple times as necessary.

[0043] By combining with the induction step, the behavior of the silkworm moths can be freely controlled, such as inducing the silkworm moths in the breeding container or the silk reeling device in a predetermined direction.

[0044] 2. Method for Controlling the Silk Spinning Position of Silkworm Moths 2-1. Overview The second aspect of the present invention is a method for controlling the silk spinning position of silkworm moths. The present invention is based on a new finding that when a silkworm moth is irradiated with light having a different main wavelength range from the behavior control light from a predetermined position, the silk spinning behavior of the silkworm moth at that predetermined position is promoted. The method of this aspect is also an embodiment of a method for reeling silk from silkworm moths.

[0045] According to the method for controlling the silk spinning position of silkworm moths of the present invention, it becomes possible to cause a silkworm moth to spin silk at a predetermined position on a substrate. Furthermore, by combining with the method for controlling the movement of silkworm moths in the first aspect, it is also possible to induce a silkworm moth to a predetermined position and induce silk spinning at that position.

[0046] 2-2. Method The method of this aspect includes a silk spinning step, which is an essential step, and an induction step and a direction control step, which are selective steps. Hereinafter, each step will be specifically described.

[0047] 2-2-1. Silk Spinning Step The "silk spinning step" is a step of irradiating a silkworm moth with silk spinning position control light from a predetermined position and causing the silkworm moth to spin silk at that position. When a silkworm moth is irradiated with silk spinning position control light, the silk spinning at the light emission position is promoted. This step utilizes this characteristic.

[0048] The wavelength and light intensity of the silk-spinning position control light are not particularly limited. When more efficiently causing the silkworm to spin silk, it is preferable to irradiate specific wavelength light as the silk-spinning position control light. The specific wavelength light referred to here means light having a high silk-spinning effect on the silkworm. The specific wavelength light in this step may be the same wavelength light as the specific wavelength light used in the silkworm movement control method of the first aspect, or may be different wavelength light. The silk-spinning position control light is preferably light having a high silk-spinning effect. Specifically, it corresponds to light having a wavelength in the range of 560 nm ± 150 nm (410 nm or more and 710 nm or less), 560 nm ± 140 nm (420 nm or more and 700 nm or less), 560 nm ± 130 nm (430 nm or more and 690 nm or less), 560 nm ± 120 nm (440 nm or more and 680 nm or less), or 560 nm ± 110 nm (450 nm or more and 670 nm or less). The basic configuration other than the wavelength regarding the silk-spinning position control light conforms to the specific wavelength light in the induction step of the first aspect. For example, the irradiation conditions and light-shielding conditions may be performed according to the induction step of the first aspect. Therefore, the description of overlapping features is omitted here.

[0049] In this step, the "predetermined position" refers to the position where the silkworm should spin silk. Usually, it refers to the target position on the surface of the substrate where the silkworm should spin silk. In the silkworm silk-spinning position control method of the present invention, the silkworm may be placed at the predetermined position, or the silkworm may be induced and placed at the predetermined position from another place by the induction step and the direction control step described later. The "placing the silkworm" referred to here means positioning the silkworm at the predetermined position for the purpose of collecting the silkworm silk thread.

[0050] The number of silkworms placed in this step is not limited. For example, one silkworm may be placed at the predetermined position, or a plurality of silkworms may be placed. Also, the type and age of the silkworms to be placed are not limited. When a plurality of silkworms are placed, each individual may be of the same species and / or the same age, or may be of different species and / or different ages.

[0051] The period of this process is not particularly limited. It depends on the type, age, and number of silkworms used. In any case, it may continue until the required amount of silk is spun at a predetermined position. As an example, when using one last-instar silkworm of the Japanese silk moth to spin silk on a circular substrate with a diameter of 9 cm as the predetermined position, it can be spun for 1 day or more, 2 days or more, 3 days or more, 4 days or more, 5 days or more, 6 days or more, 7 days or more. Since the silkworm's foothold silk is spun as it moves as described above, the amount of silk obtained is generally proportional to the moving distance of the silkworm. Therefore, spinning with multiple silkworms rather than a single silkworm can shorten the time of the spinning process. Also, since the silkworm often stops spinning during this process to continue spinning without feeding, in such cases, it can be replaced with a new silkworm and the spinning process can continue.

[0052] To increase the amount of silk spun per unit time by the silkworm, it is better that the temperature and humidity during this process are constant or change little. The temperature is preferably around 25°C, for example, within the range of 20°C to 30°C, or 23°C to 27°C, and the humidity is preferably around 50%, for example, within the range of 40% to 65%, or 45% to 60%. There is no particular limitation on the light and dark periods during this process. It may be only the light period, or a periodic light and dark period may be given. For example, within 24 hours, the light period can be 6 hours to 18 hours, 7 hours to 17 hours, 8 hours to 16 hours, 9 hours to 15 hours, 10 hours to 14 hours, 11 hours to 13 hours, or 12 hours, and the rest can be the dark period.

[0053] The material constituting the substrate on which the mites are placed is not particularly limited as long as the mites can fix the mite silk on its surface when moving. For example, glass (including hollow), metal, synthetic resin (including thermoplastic resin, thermosetting resin, synthetic rubber), ceramics, or paper and plant pieces (e.g., including wood chips), animal pieces (e.g., including bone pieces, shells, sponges) can be mentioned. Synthetic resins include polyethylene, polypropylene, polystyrene, vinyl acetate, cellulose acetate, acrylic resin, and polycarbonate, etc. In view of the method of the present invention for controlling the behaviors such as the movement and silk spinning of mites by light irradiation, the substrate is preferably a transparent substrate or a translucent substrate. A transparent substrate refers to a substrate having a very high light transmittance and the property that the opposite side can be seen through the material. For example, glass, polyethylene, polystyrene, acrylic resin, etc. can be mentioned. A translucent substrate refers to a substrate having the property of transmitting light, but due to its low light transmittance, the shape, etc. of the opposite side cannot be clearly recognized or can hardly be recognized through the material. For example, polypropylene, ground glass, etc. can be mentioned.

[0054] The thickness of the substrate is not limited. It may be appropriately determined in consideration of the manufacturing cost, rigidity, ease of processing in subsequent processes, etc. of the substrate. For example, it is preferable that the average thickness of the substrate is 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, 1.0 mm or more, 1.2 mm or more, or 1.5 mm or more, and further 3.0 mm or less, 2.8 mm or less, 2.5 mm or less, 2.2 mm or less, or 2.0 mm or less. When the substrate is composed of a thin film with an average thickness less than 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, or 0.5 mm, since the substrate itself does not have the rigidity to maintain a certain shape, the substrate may be placed on a suitable support.

[0055] As used herein, the "support" is a member that can impart rigidity and / or shape to a substrate. Usually, the substrate is disposed on its surface. The material of the support is not particularly limited as long as it has rigidity enough to maintain a certain shape. For example, glass, metal, plastic, synthetic rubber, ceramics, or paper, plant pieces, or animal pieces can be mentioned. In view of the features of the present invention, the support is preferably a transparent substrate or a translucent substrate, similar to the substrate.

[0056] The shape and size of the substrate used in this step are not limited. The shape may be, for example, a planar shape such as a sheet shape or a plate shape, a simple or complex three-dimensional shape, or a combination thereof. Usually, even a substrate (three-dimensional structure) having a three-dimensional shape that is difficult to spin silk, in the present invention, it is also possible to spin silk on the entire surface. The size of the substrate may also be set to a size as required, but in view of the fact that the scaffold silk is the silkworm silk spun as it moves, the lower limit is preferably a size equal to or greater than the body length of the silkworm. For example, the major axis or the major diameter can be 1 cm or more, 2 cm or more, 3 cm or more, 4 cm or more, or 5 cm or more. On the other hand, the upper limit of the size of the substrate is not limited, but when the major axis or the major diameter is 10 cm or more, 15 cm or more, 20 cm or more, 25 cm or more, or 30 cm or more, it is preferable to spin silk on a plurality of silkworms.

[0057] 2-2-2. Induction process and direction control process The induction process and the direction control process of the present invention are optional processes in the method for controlling the silk-spinning position of the silkworm. The description of the specific procedures and the like of these processes shall be in accordance with the induction process and the direction control process in the method for controlling the movement of the silkworm in the first aspect.

[0058] In the method for controlling the silk-spinning position of the silkworm moth according to this aspect, the silk-spinning process, which is an essential process, enables the silkworm moth to spin a support silk thread at a predetermined position. However, when irradiated with the silk-spinning position control light, as a result of inducing the silk-spinning behavior of the silkworm moth, the movement of the silkworm moth is suppressed. Therefore, after the completion of silk-spinning at a predetermined position, in order to continue silk-spinning at the next predetermined position, the method for controlling the behavior of the silkworm moth according to the first aspect may be incorporated into the method of this aspect. That is, after the silk-spinning process, the irradiation light is switched from the silk-spinning position control light to the behavior control light, and if the silkworm moth is irradiated while controlling the light emission direction to a new predetermined target position, the silkworm moth can be induced to the new predetermined position. After reaching the new predetermined position, the irradiation light may be switched from the behavior control light to the silk-spinning position control light again, and the silk-spinning behavior may be induced at that position. By repeating this, even when there are a plurality of predetermined positions where the support silk thread should be spun, it becomes possible to continuously induce silk-spinning.

[0059] In the method for controlling the silk-spinning position of the silkworm moth of the present invention, the induction step and the direction control step may be performed before or after the silk-spinning step, and the order thereof does not matter.

[0060] 2-3. Effects According to the method for controlling the silk-spinning position of the silkworm moth of the present invention, regardless of the planar structure or the three-dimensional structure, it is possible to spin a support silk thread at a specific position on the surface of a substrate of any shape. In addition, it is also possible to spin on the entire surface of a three-dimensional structure having a complex shape. As a result, it is possible to produce a mass of silk threads of the silkworm moth silk composed of support silk threads having a desired three-dimensional shape. Such a mass of silk threads can also be made into a complex shape that cannot be produced even by pressing a sheet-like silkworm moth silk. Further, by making the substrate used in the method for producing the silkworm moth silk into a material that can be dissolved in a solvent that does not physically or chemically damage the silkworm moth silk, after the silk-spinning process, by dissolving the substrate with the solvent, it is also possible to produce a mass of silk threads having a desired shape composed only of the silkworm moth silk. Such a mass of silk threads can be used, for example, as a scaffold material in regenerative medicine.

[0061] 3. Moth Silk Reeling Device 3-1. Overview The third aspect of the present invention is a moth silk reeling device. The moth silk reeling device of the present invention is a device that embodies the method for controlling the silk-spinning position of the moth in the second aspect, and can cause the caterpillar to spin a foothold thread at a predetermined position on the base material by placing the base material to be silk-spun on the device.

[0062] 3-2. Configuration The moth silk reeling device of the present invention includes a first light source as an essential component, and a second light source and / or a housing as optional components. Hereinafter, each component will be specifically described.

[0063] 3-2-1. First Light Source The "first light source" is the silk-spinning position control light described in the method for controlling the silk-spinning position of the moth in the second aspect, specifically, light in the visible light range of 560 nm ± 150 nm, 560 nm ± 140 nm, 560 nm ± 130 nm, 560 nm ± 120 nm, or 560 nm ± 110 nm, which has a high silk-spinning effect on the moth. In the device of the present invention, the first light source is configured to be radiable from any direction with respect to the base material installed in the device. The first light source can also be used as a light source for controlling the silk-spinning position of the moth.

[0064] The first light source is not particularly limited as long as it can emit light with a wavelength within the above wavelength range. Preferred light sources include, for example, LEDs. Since the wavelength spectrum of an LED shows a waveform having peak light of a specific wavelength, it is preferred as the light source of the present invention. However, as described above, even a light source that emits light without a peak wavelength, such as a fluorescent lamp or a mercury lamp, is not limited as long as only the transmitted light selected through a wavelength selection filter can be irradiated as the silk-spinning position control light.

[0065] The first light source only needs to have at least one provided in the device, but it may also have a plurality. In the case of a plurality, the light sources may be installed so as to face the same direction with respect to the base material, or each may be installed so as to face a different direction with respect to the base material. Further, as long as it is a light source capable of emitting light of the wavelength range, each light source may be a light source capable of emitting light of different wavelengths, for example, light of different peak wavelengths.

[0066] When a plurality of first light sources are provided, each light source may be configured to be able to emit light simultaneously or at different timings.

[0067] The first light source may be movable. For example, there are configurations such as mounting the light source on a flexible arm installed in the device so as to be able to emit light from an arbitrary direction with respect to the base material installed in the device, or installing a rail in the device and making the light source movable on the rail.

[0068] The spinning position control light emitted from the first light source may be configured to be directly irradiated onto the base material arranged in the device, or may be configured to be indirectly irradiated onto the base material via one or more reflectors. In this case, the device can include one or more reflectors. Each reflector may be configured to be able to change the reflection angle in order to adjust the light reflection position.

[0069] 3-2-2. Second Light Source The "second light source" is a light source capable of emitting action control light described in the method for controlling the movement of the mealworm in the first aspect, specifically, light of a wavelength in the range of 405 nm ± 60 nm, 405 nm ± 55 nm, or 405 nm ± 50 nm. In the device of the present invention, the second light source is configured to be able to emit light from an arbitrary direction onto the base material installed in the device to move the mealworm to an arbitrary position on the base material. The second light source can also be used as a light source for controlling the behavior of the mealworm.

[0070] The first light source and the second light source can also be used interchangeably. In that case, it suffices to be configured to emit wavelength light in a wavelength range where both the attracting action and the silk-spinning action are maximized. For example, wavelength light in the range of 410 nm or more and 465 nm or less can be mentioned.

[0071] The basic configuration of the second light source is basically the same as that of the first light source except that the range of the wavelength light to be emitted is different, so the description here is omitted.

[0072] 3-2-3. Housing The "housing" is a component that provides a light-shielded environment for the mealworm silk-reeling device of the present invention and is an optional component of this device. The light-shielded environment is usually provided inside the housing. Therefore, the housing in this device is configured to be able to arrange at least mealworms and the silk-spinning base material inside it. The first light source or the second light source, or their reflectors, may be arranged inside the housing.

[0073] 3-2-4. Base material The "base material" is not a component in the mealworm silk-reeling device of the present invention but a member provided for this device. Regarding the material and shape of the base material, etc., it conforms to the base material described in the silk-spinning process in the method for controlling the silk-spinning position of mealworms in the second aspect.

[0074] 3-3. Effects The mealworm silk-reeling device of the present invention is an invention that embodies the method for controlling the silk-spinning position of mealworms in the second aspect into a device. By arranging a base material to be silk-spun and mealworms in the device and executing, it is possible to make the mealworms spin foothold silk at a predetermined position on the base material. According to this device, it is possible to spin silk at a predetermined position on the surface of a base material having a complex three-dimensional structure.

Example

[0075] <Example 1: Verification of wavelength light for attracting mealworms> (Purpose) In order to confirm the light attractiveness of mealworms, wavelength light having various wavelength peaks is simultaneously irradiated from the side to verify which wavelength light the mealworms are attracted to. (Method) For the mealworms, 20 final-instar larvae of the same size as the waxworms were used.

[0076] For the test apparatus, with reference to the test apparatus developed for the purpose of examining the wavelength preference of stink bugs (Takumi Ogino et al., 2015, Japanese Journal of Applied Entomology and Zoology, 59: 10 - 13), an apparatus was fabricated in which eight light sources with different wavelengths were arranged at angular intervals of 45° on the side surface of a cylindrical container with a radius of 120 mm and a height of 30 mm, the entire surface of which was composed of a light-shielding material (Figure 1). As the light sources, LEDs having peak wavelengths at (a) 365 nm (ultraviolet light), (b) 405 nm (violet light), (c) 450 nm (blue light), (d) 490 nm (cyan light), (e) 545 nm (green light), (f) 590 nm (yellow light), (g) 630 nm (orange light), and (h) 660 nm (red light) were used (Figure 2). As shown in Figure 2, the light intensities of the LEDs used were almost unchanged. After placing one of the above mealworms in a depression with a diameter of 15 mm and a depth of 60 mm provided in the central part of this test apparatus, the eight light sources were simultaneously turned on, and the light source that the mealworm reached first was examined. The same test was repeated for 20 different mealworms, and the number of individuals reaching each wavelength of light was measured.

[0077] (Results) Figure 3 shows the number of individuals reaching each light source wavelength. As shown in Figure 3, when irradiating each wavelength of light simultaneously, more individuals of the mealworms were attracted to the short-wavelength light than to the long-wavelength light. However, it became clear that the wavelength range of ±60 nm centered on 405 nm was the most effective, rather than being more strongly attracted the shorter the wavelength. This result suggests that by irradiating the mealworms with behavior-control light of 405 nm ± 60 nm, the mealworms can be induced in the direction of the light emission.

[0078] <Example 2: Behavior Control and Silk-Spinning Position Control on a Desired Surface of a Three-Dimensional Structure> (Objective) In Example 1, it was confirmed that by irradiating the behavior control light, the clothes moth can be effectively induced in the light emission direction of the behavior control light. In this example, by irradiating the silk-spinning position control light on the clothes moth, it is verified that a silk mass can be efficiently produced at a predetermined position of the three-dimensional structure. (Materials and Methods) For the clothes moth, the last instar larvae of the same size of the wax moth were used.

[0079] The apparatus shown in Figure 4 was used in the test. As shown at A, this apparatus consists of four main parts: two cubes (cages; 0401, 0403) composed of light-shielding and non-reflective members with a side length of 100 mm, a light-shielding and non-reflective square plate (0402) with a side length of 100 mm, and a light source (0406). The square plate (0402) has a large square window (0405) in the central part, and a nylon mesh described later is attached to this window. The two cubes (0401, 0403) are box-shaped with one side of the six sides open, and are configured such that their open surfaces can be opened and closed with the square plate (0402) sandwiched in between. When the open surfaces are closed, the internal spaces of the two cubes (0401, 0403) are isolated by the square plate (0402), forming two dark chambers. The mealworms are placed in one of the cages (0401). Nylon meshes (0404) for assisting the movement of the mealworms are attached to all six inner wall surfaces of the cage where the mealworms are placed. The other one is equipped with a light source (0406) on the surface opposite to the open surface, and is configured to be able to irradiate light into the internal space. The light emitted from the light source with the open surface closed reaches the inside of the cage (0401) through the window (0405). As a result, the surface where light can enter the cage is only the light-emitting surface, and the other surfaces are completely light-shielded, and no light from the outside can enter. Also, the light that has entered from the light-emitting surface by the non-reflective member is not reflected on each surface. By the above operation, a test system was constructed in which light irradiation by an LED light source is possible at a distance of 100 mm from the light-emitting surface of the cubic cage (0401). Eight types of light sources were prepared: ultraviolet LED (maximum wavelength 365 nm), purple LED (405 nm), blue LED (450 nm), blue-green LED (490 nm), green LED (545 nm), yellow LED (590 nm), orange LED (630 nm), and red LED (660 nm). As a negative control, a dark state experimental area without a light source was added, and the weight of the silk masses of the mealworms on each surface was compared under a total of nine conditions. The 10 mealworms introduced were replaced with newly well-fed mealworms every 2 to 4 days, and the experiment was continued for a total of 13 days. During the experiment, the temperature of the test system was maintained at 26°C. Thirteen days after the start of the experiment, the silk masses of the mealworms that had spun silk on the side surfaces were collected, and the weight of the silk masses was measured for each surface.As shown in B of FIG. 4, each side surface has a light-emitting surface designated as "side surface 1", and "side surfaces 2 to 4" in the clockwise direction when viewed from above.

[0080] Regarding the upper surface, the weight of the silk mass was measured only under the dark conditions of the negative control, while the bottom surface was excluded from the measurement targets. The reason is that for the upper surface, it was revealed from the results described later that the instinctive property of the mealworm preferring high places is maintained even under darkness and it spins silk regardless of light induction. Also, for the bottom surface, it is the place where the mealworm is initially placed, and when moving to each surface, it spins silk regardless of light induction.

[0081] (Results) Under the dark conditions of the negative control, the weight of the silk mass on the upper surface was the highest among the four side surfaces (data not shown). This is due to the instinctive property of the mealworm moving to high places and trying to stay in that position. Therefore, in order to exclude the influence of the upward movement of the mealworm and compare only the influence of the wavelength of light on the silk-spinning behavior, the ratio of the weight of the silk mass on the light-emitting surface (side surface 1) to the average weight of the silk masses on the other three side surfaces (side surfaces 2, 3, 4) was calculated to compare the light of each wavelength.

[0082] The results are shown in FIG. 6. Under the light irradiation conditions, it was confirmed that except when irradiating with short-wavelength light of 365 nm and 405 nm, the weight of the silk mass on side surface 1, which is the light-emitting surface, was more than twice that of the average weight of the silk masses on the other side surfaces. Surprisingly, the ratio of the weight of the silk mass on side surface 1 was the lowest when irradiating with the wavelength light of 405 nm, which attracted the mealworm most strongly in Example 1, while it showed a high value when irradiating with the wavelength light from 450 nm to 660 nm. This result suggests that the wavelength of the behavior control light with a high attracting effect and the wavelength of the silk-spinning position control light with a high silk-spinning effect do not necessarily match.

[0083] From the above results, according to the present invention, by irradiating the behavior control light from a desired position of the three-dimensional structure, attracting the mealworm to that position, and then switching to and irradiating the silk-spinning position control light at that position, it has been shown that it is possible to efficiently form a silk mass at the desired position. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety.

Claims

1. A step of irradiating a silk-spinning position control light to a clothes moth from a predetermined position on a base material, and spinning a scaffold silk thread onto the clothes moth at the position, A method for controlling the silk-spinning position of a clothes moth, wherein the wavelength of the silk-spinning position control light is 560 nm ± 150 nm.

2. The method for controlling the silk-spinning position according to Claim 1, including a step of irradiating an action control light with a wavelength of 405 nm ± 60 nm to a clothes moth from a predetermined position on the base material to induce the clothes moth to the position.

3. The method for controlling the silk-spinning position according to Claim 1 or 2, which is performed under light-shielding conditions.

4. The method for controlling the silk-spinning position according to any one of Claims 1 to 3, wherein the base material is a three-dimensional structure.

5. The method for controlling the silk-spinning position according to any one of Claims 1 to 4, wherein the base material is a transparent base material or a light-transmissive base material.

6. A method for producing a mass of clothes moth silk thread obtained by using the method for controlling the silk-spinning position of a clothes moth according to any one of Claims 1 to 5.

7. A clothes moth silk thread collecting device including one or more light sources capable of emitting a silk-spinning position control light with a wavelength of 560 nm ± 150 nm from an arbitrary direction to a base material for spinning a scaffold silk thread onto a clothes moth.

8. The device according to Claim 7, further including one or more light sources capable of emitting an action control light with a wavelength of 405 nm ± 60 nm from an arbitrary direction to the base material.

9. The device according to Claim 7 or 8, wherein the light source is movable.

10. The device according to any one of Claims 7 to 9, including a housing having a light-shielding environment inside.

11. Use of a light source capable of emitting light in the range of 560 nm ± 150 nm for controlling the silk-spinning position of a clothes moth silk thread.

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