Agent for accelerating growth of bagworms

Abstract

The present invention pertains to an agent for accelerating the growth of bagworms, the agent containing an artificial feed for herbivorous animals.

Description

Agent for accelerating the growth of bagworms

[0001] The present invention relates to an agent for accelerating the growth of bagworms.

[0002] Bagworm is a general term for larvae of moths (Psychidae) belonging to the family Psychidae of the order Lepidoptera. The silk spun by this insect (bagworm silk) has higher physical properties than silk spun by silkworms (silkworm silk) and spider silk spun by spiders, so it has attracted attention in recent years as a new natural animal fiber material (Patent Document 1 and Non-Patent Document 1).

[0003] For the practical application and industrialization of bagworm silk as a fiber material, the establishment of mass rearing technology for bagworms is indispensable, and therefore a technology for early growth of bagworms is required.

[0004] WO2019 / 003364

[0005] Shigeo Osaki, 2002, Journal of the Fiber Society of Japan (Fiber and Industry), 58: 74-78.

[0006] An object of the present invention is to provide a technique for accelerating the growth of bagworms.

[0007] As a result of intensive studies conducted by the present inventors to solve the above problems, when an artificial feed for herbivores is supplied to bagworms, a new finding that the growth of bagworms is accelerated has been obtained. The present invention was completed based on the further new finding that the survival rate of bagworms is also improved. The present invention provides the following inventions [1] to [6].[]

[0008] [1] A growth accelerator for bagworms containing artificial feed for herbivores. [2] The growth accelerator for bagworms according to [1], wherein the artificial feed for herbivores is artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer. [3] Use of artificial feed for herbivores as a growth accelerator for bagworms. [4] Use according to [3], wherein the artificial feed for herbivores is artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer. [5] A method for accelerating the growth of bagworms, characterized by providing artificial feed for herbivores. [6] The method according to [5], wherein the artificial feed for herbivores is an artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer.

[0009] By providing the bagworm growth accelerator of the present invention to bagworms, the growth of bagworms, particularly the growth rate of mid- to late-stage bagworms, can be accelerated. Furthermore, the survival rate can be improved. In addition, by shortening the bagworm growth period, silk threads can be harvested earlier as a fiber material.

[0010] One aspect of the present invention is a growth accelerator for bagworms containing artificial feed for herbivores. Another aspect of the present invention is the use of artificial feed for herbivores as a growth accelerator for bagworms. Yet another aspect of the present invention is a method for accelerating the growth of bagworms, characterized by providing artificial feed for herbivores. The growth accelerator for bagworms of the present invention is characterized by containing artificial feed for herbivores as an essential component. When the growth accelerator of the present invention is provided to bagworms, the growth of the bagworms, especially mid- to late-stage bagworms, can be accelerated compared to a control that does not receive the growth accelerator.

[0011] In this specification, "growth acceleration" means increasing the growth rate. This shortens the growth period compared to the control under normal conditions.

[0012] In this specification, "bagworm" refers to the larvae of moths belonging to the family Psychidae, order Lepidoptera. Moths of the Psychidae family are distributed worldwide, but the bagworms referred to in this specification may be any species. For example, but not limited to, species belonging to Acanthopsyche, Anatolopsyche, Bacotia, Bambalina, Canephora, Chalioides, Dahlica, Diplodoma, Eumeta, Eumasia, Kozhantshikovia, Mahasena, Nipponopsyche, Paranarychia, Proutia, Psyche, Pteroma, Siederia, Striglocyrbasia, Taleporia, Theriodopteryx, and Trigonodoma are examples. Furthermore, the sex and age of the bagworms discussed herein are not considered.

[0013] In this specification, "mid-stage bagworm" refers to a bagworm in its middle instar stage. While not limited to this, it generally refers to bagworms that maintain a nest with a long axis of 10 mm or more but less than 20 mm, and are generally in the 3rd to 4th instar.

[0014] In this specification, "late-stage bagworm" refers to a bagworm in its later stages of life. While not limited to this, it generally refers to bagworms that maintain a nest with a long axis of 20 mm or more, and are generally in the 5th instar or later.

[0015] In this specification, "herbivore" refers to a vertebrate that primarily feeds on plants or substances derived therefrom. While not limited to all herbivores, this term mainly includes reptiles and mammals. Examples of herbivorous reptiles include tortoises and iguanas. Examples of herbivorous mammals include rabbits, guinea pigs, voles, cows, horses, goats, sheep, giraffes, antelopes, and deer.

[0016] In this specification, "artificial feed for herbivores" refers to feed artificially produced for the diet of herbivores. Herbivore feed may be a highly versatile artificial feed that can be given to an unspecified number of herbivores, or it may be a species-specific artificial feed developed for a specific herbivorous species. Examples of non-species-specific artificial feeds include artificial feeds for herbivorous reptiles that can be used for various herbivorous reptiles, or artificial feeds for herbivorous mammals that can be used for various herbivorous mammals. These artificial feeds for herbivores may be produced based on compositions known in the art, but commercially available products may also be used. For example, examples of artificial feeds for herbivorous reptiles include Malberic Dry (Kyorin Co., Ltd.), Rick Jelly (Kyorin Co., Ltd.), and Tortoise Food (Sudo Co., Ltd.). Examples of artificial feeds for herbivorous mammals include ZF, ZC, ZHF, LRC4, and GOC4 (all from Oriental Yeast Co., Ltd.).

[0017] Artificial feed for herbivores may be crushed, coarsely chopped, medium-chopped, or finely chopped as needed by known methods, taking into consideration convenience for bagworm feeding, as well as transportation and storage. The length and thickness after crushing or cutting are not particularly limited. The length may be, for example, 0.001 mm to 100 mm, 0.005 mm to 80 mm, 0.01 mm to 60 mm, 0.03 mm to 50 mm, 0.05 mm to 40 mm, 0.08 mm to 30 mm, 0.1 mm to 25 mm, 0.3 mm to 20 mm, 0.5 mm to 15 mm, 0.8 mm to 12 mm, 1 mm to 10 mm, 2 mm to 8 mm, 3 mm to 6 mm, or 4 mm to 5 mm. Furthermore, the thickness can be, for example, 0.001 mm to 10 mm, 0.005 mm to 8 mm, 0.01 mm to 6 mm, 0.03 mm to 5 mm, 0.05 mm to 4 mm, 0.08 mm to 3 mm, 0.1 mm to 2.5 mm, 0.3 mm to 2 mm, 0.5 mm to 1.5 mm, 0.8 mm to 1.2 mm, or 1 mm.

[0018] Furthermore, the artificial feed for herbivores may be a powder obtained by grinding using a known method. The particle size may be 0.001 mm to 1 mm, 0.002 mm to 0.8 mm, 0.005 mm to 0.6 mm, 0.008 mm to 0.5 mm, 0.01 mm to 0.4 mm, 0.02 mm to 0.3 mm, 0.04 mm to 0.2 mm, 0.05 mm to 0.18 mm, 0.06 mm to 0.15 mm, 0.08 mm to 0.12 mm, or 0.09 mm to 0.1 mm.

[0019] The growth-accelerating agent of the present invention is supplied to bagworms through ingestion or use as nesting material. The method of supply is not particularly limited, and the growth-accelerating agent of the present invention may be supplied to bagworms alone or together with other supplies.

[0020] An example of providing the product together with other materials is providing it with bagworm feed. Examples of feed include leaves, buds, flowers, and branches containing these, collected from broad-leaved or coniferous trees. For example, if the feed is made from the leaves of a coniferous or broad-leaved tree, the growth accelerator of the present invention may be applied to it before providing. Alternatively, the growth accelerator of the present invention may be mixed with the feed before providing. When mixing, it is preferable to use the growth accelerator of the present invention in a form that has been crushed, cut, or pulverized.

[0021] Furthermore, artificial feeds for leaf-eating lepidopteran insects can be used as feed for bagworms, such as artificial feeds for silkworms. Artificial feeds can be manufactured based on known compositions (Hirayama, 2020, Sericulture and Insect Biotechnology 89(2):91-96, Horie, Y. and Ito, T., 1965, J. Insect Physiol., 11, 1585-1593, etc.), or commercially available products such as Insecta (Nippon Nosan Kogyo Co., Ltd.) and Silkmate (Nippon Nosan Kogyo Co., Ltd.) can be used.

[0022] <Examples> (Objective) To verify the number of days of development, survival rate, and body size when the growth accelerator of the present invention is administered to bagworms.

[0023] (Methods) (1) First instar bagworms of the giant bagworm moth (Eumeta variegata; syn. E. japonica) from the same brood were reared under the same conditions, fed artificial feed and cork nesting material, and individuals corresponding to the fourth instar, with a maximum short axis of the nest of approximately 8 mm and a long axis of approximately 20 mm, were used.

[0024] (2) Rearing container and bagworm nesting material An acrylic box-shaped container with dimensions of width x depth x height = 220 mm x 220 mm x 200 mm and a thickness of 5 mm was used for the rearing container. For the bagworm nesting material, cork pieces cut from a 0.5 mm thick cork board into strips of 10 mm x 150 mm to 170 mm were used. The cork pieces were arranged so that both ends of each piece were in contact with the bottom and top surfaces of the rearing container, and were secured to the wire mesh on the top surface of the rearing container.

[0025] (3) Feed - Control group Feed A consisted only of Silkmate (Nippon Nosan Kogyo Co., Ltd.). - Test group Feed B consisted of feed A with 1 / 3 by weight of Silkmate (Nippon Nosan Kogyo Co., Ltd.) replaced with rabbit and guinea pig feed (LRC4: Oriental Yeast Co., Ltd.).

[0026] The 80 bagworms mentioned above were randomly divided into two groups of 40 each and placed in separate rearing containers. Each group was fed feed A and feed B. The feed consisted of a 1 cm thick plate-shaped artificial feed placed on the feed placement area on the top of the rearing container, covering the entire ceiling.

[0027] (4) Rearing conditions During the rearing period, the temperature and humidity inside the rearing container were adjusted to 25 ± 1.5°C and the relative humidity to 70 ± 10% RH in order to prevent the feed from drying out and to maintain the activity of the bagworms. To unify the light and dark conditions in each of the above sections, the rearing containers for the two sections were placed next to each other in a laboratory that was set to 16 hours of light and 8 hours of darkness using LEDs. During the rearing experiment, the artificial feed was changed, bagworm nesting material was added, and the inside of the rearing container was cleaned once a week.

[0028] (5) From the ninth week after the start of the data collection experiment, the presence or absence of pupation was checked for all individuals once a week. For individuals that had pupated, the sex was determined and the long axis of the nest was measured with calipers. This experiment was continued until all individuals had pupated or died.

[0029] (Results) (1) Development period The average development period for females was 99.3 days (N=14) in the control group, compared to 86.2 days (N=20) in the experimental group, which was about 13 days shorter in the experimental group. Similarly, the average development period for males was 67.0 days (N=23) in the control group, compared to 59.2 days (N=20) in the experimental group, which was significantly about 8 days shorter in the experimental group.

[0030] These results demonstrate that administering the bagworm growth accelerator of the present invention significantly shortened the development period of bagworms, thus accelerating their growth.

[0031] (2) Pupation rate The pupation rate in the control group was 92.5%, and the pupation rate in the test group was 100%. The pupation rate is proportional to the survival rate during the larval stage. From these results, it was proven that administering the bagworm growth accelerator of the present invention can improve the survival rate of bagworms in the mid-to-late stage.

[0032] (3) In females, the average nest length was 36.7 mm (n=14) in the control group and 38.5 mm (n=20) in the test group, showing almost no difference. Similarly, in males, the average was 32.3 mm (n=23) in the control group and 32.1 mm (n=20) in the test group, showing almost no difference.

[0033] In the test plot of this embodiment, 30% of the insect artificial feed used in the control plot was replaced with the growth accelerator of the present invention. The growth accelerator of the present invention is composed of inexpensive and readily available artificial feed for herbivores. By using the growth accelerator of the present invention, the amount of expensive insect artificial feed used can be reduced, thereby lowering costs, while accelerating the growth of bagworms without adversely affecting them and improving their survival rate. This makes it possible to reduce the effort and time required for rearing.

Claims

1. A growth accelerator for bagworms, including artificial feed for herbivores.

2. The bagworm growth accelerator according to claim 1, wherein the artificial feed for herbivores is an artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer.

3. Use of artificial feed for herbivores as a growth accelerator for bagworms.

4. The use according to claim 3, wherein the artificial feed for herbivores is an artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer.

5. A method for accelerating the growth of bagworms, characterized by providing artificial feed for herbivores.

6. The method according to claim 5, wherein the artificial feed for herbivores is an artificial feed for tortoises, iguanas, rabbits, guinea pigs, voles, cattle, horses, goats, sheep, giraffes, serows, or deer.