Next-Generation Protein Nurtured by Sericulture Culture: Effectiveness of Terrestrial Aquaculture Feed Derived from Wild Silkworm Elisone Demonstrated.

Amidst global challenges of soaring fishmeal prices and reliance on natural resources, Insect Technology Co., Ltd. (Headquarters: Uruma City, Okinawa Prefecture; Representative Director: Shin Tainaka) is advancing research into alternative feeds utilizing wild silkworm elisone (family Saturniidae).
Insect Technology Co., Ltd. has now collaborated with the National University Corporation University of the Ryukyus to verify the effectiveness of a compound feed for terrestrial aquaculture using elisone pupae as a raw material, thereby demonstrating its efficacy as aquaculture feed.

In the experiment, groupers (Mi-bai) were raised using a test feed that incorporated elisone pupae as a 15% substitute for fishmeal. Favorable results were obtained in terms of weight gain rate, survival rate, and feed efficiency. Furthermore, the potential for reducing stress in farmed fish raised under high-density conditions was also confirmed.

As an initiative towards the social implementation of these research outcomes, a tasting event for farmed fish raised on elisone-derived feed, titled 'Local Blue Table 2026,' will be held on Friday, June 26th.

1. Joint Experiment with the University of the Ryukyus: Developing Sustainable Feed Available Domestically

① Overview of Experimental Design
Insect protein feed using elisone (family Saturniidae) pupae as raw material was incorporated as a 15% replacement for fishmeal. A comparative test was conducted between this and conventional fishmeal-based feed. The crude protein and lipid content were designed to be identical for both groups.
- Target Fish Species: Grouper (Mi-bai) - High-value farmed fish from Okinawa
- Replacement Rate: For every 100g, fishmeal was reduced from 60g to 45g, and 15g of elisone pupae powder was added.
- Feeding Period: October 29, 2025 - December 25, 2025
- Implementing Institution: Research Organization of the University of the Ryukyus, National University Corporation

② Major Research Findings: Confirmation that Elisone-Derived Protein Can Serve as a Fishmeal Substitute
- Weight Gain Rate: Growth equivalent to fishmeal feed was confirmed. Elisone-containing feed: 156.7% / Fishmeal-containing feed: 153.9%
- Survival Rate: 100% - Achieved throughout the entire rearing period.
- Feed Efficiency: No adverse effects - Feed conversion efficiency equivalent to fishmeal-containing feed was confirmed.

③ Noteworthy Findings: The Potential of 'Silk-Fed Fish' for Producing Healthy Fish
Physiological changes were observed in fish that consumed the elisone-containing feed:
- Reduction in oxidative stress markers (TBARS/MDA values) and cortisol levels (stress hormone).
- Slightly elevated blood glucose levels (Glucose) - Indicating a state of active metabolism.
These results suggest that the antioxidant components in elisone reduce oxidative stress in fish, leading to improved quality and health by reducing stress in fish raised in high-density, closed-system aquaculture. This finding indicates the potential of elisone pupae powder not just as a substitute ingredient but as a 'functional feed ingredient.'

④ Comments from Joint Research Partners
- Koudai Fukunaga, Specially Appointed Assistant Professor, University of the Ryukyus
"This experiment has shown that raw materials derived from wild silkworm elisone can function as a partial substitute for fishmeal. These findings are significant as a new feed option for sustainable aquatic resource utilization, and we will proceed with verification for practical application."
- Taegyeong Seong, Specially Appointed Assistant Professor, University of the Ryukyus
"While much research has been conducted on feeds using insect-derived materials, studies on aquaculture feeds focusing on elisone pupae are limited. Considering elisone's broad diet and the potential for utilizing underutilized local resources, its future development as a sustainable feed ingredient is highly anticipated."

Furthermore, the verification of the effectiveness of the compound feed for terrestrial aquaculture and its efficacy as aquaculture feed was conducted with the support of the 2025 Spring Grant Program for Environmental Initiatives (Food Systems) by the PwC Charitable Foundation.

2. Event Hosting: Co-creating Terrestrial Aquaculture as a New Food Culture with 'Local Blue Table 2026'

To promote the social implementation of research outcomes, a tasting event for farmed fish raised on elisone-derived feed will be held.
'Local Blue Table' is a co-creative event that brings together not only researchers, aquaculture operators, and food-related companies who are stakeholders in terrestrial aquaculture, but also creators such as designers and architects, and students. It serves as a multi-stakeholder dialogue to examine the 'positive cycle for the region brought about by terrestrial aquaculture,' fostering consideration for the future of sustainable blue food utilizing local resources.

- Date and Time: Friday, June 26, 2026, 17:30 - 19:30 (Doors open at 17:00)
- Venue: Marked Shibuya, 1F, Shibuya Cast, 1-23-21 Shibuya, Shibuya-ku, Tokyo 150-0002
- Features: Tasting of various terrestrial aquaculture blue foods, guest talks, proposals by students from Japan Women's University, report on our company's research findings.
- Details and Registration: https://lbt2026.peatix.com/

Tasting of 'Ryukyu Silk Grouper' will also be available at the event.

3. Our Aimed Business Model: Sericulture Culture x Aquaculture Technology = Regional Food Cycle

Insect Technology Co., Ltd. aims to build a regional circular new industrial model that organically connects sericulture (Local Culture) with terrestrial aquaculture (Food Tech).

Conceptual Diagram of Insect Technology Co., Ltd.'s Business Model

[Local Culture: Elisone Sericulture]
- Utilization of food scraps and underutilized agricultural resources as feed for silkworms, establishing an intra-regional cycle.
- Collaboration with agriculture and welfare: Creating employment opportunities for people with disabilities and the elderly.
- Cocoons for the textile industry: Utilization as natural functional materials with UV-cut and deodorizing properties.

[Food Tech: Terrestrial Aquaculture Feed Development]
- Development and provision of high-functionality aquaculture feed using elisone pupae as raw material.
- Rearing of high-quality fish with antioxidant and stress-reducing effects through closed-cycle land-based aquaculture.
- Production in collaboration with sericulture sites nationwide, including Okinawa, Gunma, Saitama, Nagano, and Niigata.
- Sales as 'Silk-Fed Fish,' a local product and high-value blue food.

Insect Technology Co., Ltd. has initiated elisone sericulture not only in Okinawa but also in Tomioka City, Gunma Prefecture, the home of the World Heritage site Tomioka Silk Mill. Through the establishment of a new circular industrial model utilizing insect resources, we aim to socially implement a Japanese-originated sustainable food production system.