What if a misunderstood “pest” could help restore ecosystems, empower women, preserve cultural heritage and support climate resilience?
In Indonesia, the use of Cricula trifenestrata wild silk moths’ golden cocoons has achieved just that since the 1990s. The species is found across tropical Asia, with notable presence in Indonesia (especially Yogyakarta) and in Sulawesi, Thailand, Southern China, India and Sri Lanka.
Rooted in the Javanese philosophy Hamemayu Hayuning Bawana, to leave the world better for future generations; this initiative resonates deeply with the IUCN World Conservation Congress 2025 vision of transitioning to nature-positive economies and societies.
For over 30 years, the Royal Golden Cocoon of Java initiative has woven science, heritage and diplomacy into a living model of a nature-positive society. Initiated by the Royal Family of Yogyakarta and supported by the Yogyakarta–Kyoto Sister Provinces relationship since 1985, this collaboration has brought together Japanese scientists, Kyoto artisans and local communities in Yogyakarta, Indonesia.
What began as a grassroots effort to improve rural livelihoods has since transformed a “pest” into a functional biomaterial, showcasing how open science and cross-cultural partnerships can deliver tangible conservation solutions.
The hidden value of a “pest”
Unlike the common silk produced by the domesticated Bombyx mori, which has a smooth, nonporous surface, the wild silk of Cricula trifenestrata stands out for its unique structure.
First observed by Prof. Dr. Hiromu Akai in 1988, Cricula cocoons contain an intricate network of pores measuring just 0.1 to 0.8 microns in diameter. Among Saturniidae species, only the protected Argema mittrei (the Madagascan Moon Moth) has a higher pore density.
This natural porous structure gives Cricula silk a range of properties that are not found in conventional silk, making it what some are calling the “healthy silk” of the future. Its breathable, UV-shielding, and antimicrobial characteristics open promising uses across multiple industries.
In textiles, it offers a sustainable option for non-toxic, skin-friendly fabrics. In cosmetics, the silk proteins are valued for being non-allergenic and rich in antioxidants. In the pharmaceutical sector, pigments derived from Cricula cocoons have even been patented for use in cataract treatment. By highlighting these links between the cocoon’s porous structure and its potential for innovation, Cricula silk demonstrates how wild species can lead the way toward high-performance, nature-based materials.
Restoration and empowerment through a circular economy in Java
Just over a kilometre from the culturally significant Javanese landscape of the Imogiri Royal Tomb, built in 1632, the Cricula wild silk moth afforestation zone is helping to stabilise erosion-prone slopes along the shared ridgeline.
By planting a diversity of fruit and shade trees - preferred by the polyphagous Cricula wild silk moth - the local community reduced landslide risk and enhanced both biodiversity and cultural heritage, demonstrating how nature-based solutions can reinforce biocultural resilience. The initiative operates on zero emissions and follows a regenerative, circular model with minimal environmental impact. But its greatest strength may lie in its social impact.
Rural women, trained as Royal Wild Silk spinners, are gaining not only a steady income but also a renewed sense of purpose and identity. With greater economic independence, they are better able to protect themselves and their children from early or forced marriage.
In advancing gender equality, the project directly supports SDG 5 and offers a powerful example of how empowering women can enhance local stewardship - a key factor for inclusive, long-term conservation success under the 30 by 30 global targets being discussed at the IUCN World Conservation Congress 2025.
An open science model for global replication
With more than 160,000 known moth species around the world - many of which produce their own uniquely structured cocoons - this natural resource remains largely unexplored.
By revisiting these species through the lens of modern science and innovation, we have the chance to uncover hidden value. Access to biodiversity knowledge isn’t a luxury - it’s a basic human right, deeply tied to health, well-being, and sustainable futures. Unlocking this potential depends on open, inclusive collaboration.
Mapping widely distributed species like Cricula trifenestrata can only succeed through collaboration that ensures local communities are respected as knowledge holders and receive a fair share of the benefits; such as income and recognition arising from the use of the local natural resources.
The IUCN World Conservation Congress 2025 offers a vital opportunity to deepen knowledge exchange, build capacity, and scale solutions grounded in transparency and collective stewardship.
The Royal Golden Cocoon of Java reflects the vision of the IUCN Congress 2025 and Motion 081 on transitioning to regenerative economies. Originating as a grassroots initiative, it offers a living example of how biocultural knowledge, biodiversity stewardship, and inclusive governance can support transformative change toward nature-positive futures.
The Congress offers a timely platform to exchange practices, deepen alliances, and chart new pathways that connect biodiversity, open science, and cultural heritage. Let us scale what works, honour fair access and benefit-sharing, and ensure that every community has the knowledge, tools, and recognition they need to thrive.