Wild Silkmoth Conservation: Biodiversity, Ecoraces, and Gene Erosion

Last Updated: January 28, 2026
Estimated reading time ~8 minutes
Word count: 1,280

India holds a unique distinction in the global sericulture map as the only country producing all four commercially known varieties of silk: Mulberry, Tasar, Eri, and Muga. However, the backbone of this industry—the wild silkmoth conservation—is under threat. Unlike the domesticated Bombyx mori, wild silkmoths like Antheraea mylitta, Attacus atlas, and Actias selene depend entirely on natural forest ecosystems. This analysis draws from a doctoral thesis on Western Maharashtra’s fauna to highlight the rich biodiversity of silkmoth ecoraces, the looming threat of “gene erosion” caused by deforestation, and the imperative for in situ and ex situ conservation strategies to protect these economic insects.

Key Takeaways

• Global Unique Status: India is the exclusive producer of all four commercial silks, with “Vanya” (wild) silks like Tasar and Muga being forest-dependent.
• Ecorace Diversity: Antheraea mylitta possesses 44 diverse ecoraces (e.g., Daba, Raily, Sarihan), each adapted to specific ecological niches.
• Gene Erosion: Urbanization and indiscriminate lopping of host plants like Terminalia and Shorea are causing rapid loss of valuable silkmoth genotypes.
• Conservation Necessity: The establishment of “Seed Zones” and preservation of wild genotypes is critical to maintaining hybrid vigor and disease resistance.
• Western Ghats Hotspot: Surveys in Kolhapur and Satara reveal a rich, yet vulnerable, diversity of Saturniid moths requiring immediate protection.

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H1: Biodiversity and Conservation of Wild Silkmoths

The Wealth of Ecoraces: Nature’s Genetic Bank

The resilience of the wild silk industry lies in its genetic diversity. The thesis details how the Indian Tasar silkmoth, Antheraea mylitta, has evolved into numerous “ecoraces”—distinct populations adapted to specific local environments. These ecoraces differ in voltinism (generations per year), cocoon characteristics, and food plant preferences.

Major Ecoraces and Their Traits

• Daba: Ideally suited for commercial rearing, this bivoltine race feeds on Terminalia tomentosa and T. arjuna. It produces dark brown/yellowish cocoons with a long peduncle. It is less wild and more amenable to human handling than others.
• Raily: A wild, Sal-based (Shorea robusta) univoltine race found in dense forests. It produces the hardest cocoons (“stone-like”) with high silk content but is difficult to rear in captivity due to its wild nature.
• Sarihan & Laria: These are trivoltine races (three generations a year). Sarihan larvae exhibit vibrant polymorphism with yellow, blue, and white variants, while Laria produces yellow cocoons with long peduncles.
• Andhra Local: Adapted to shrubby vegetation, this race produces smaller cocoons but is hardy against environmental stress.

“Biodiversity within a species like tasar reveals its potentiality and the genetic adaptability through interaction with environment… Biodiversity is a way of life in wild silkworms.” (Kavane, 2010, p. 27)

Student Note: An Ecorace is a population of a species that has adapted to a specific set of environmental conditions (like altitude, humidity, or host plant) but is not yet a separate subspecies. Preserving these races is vital for breeding programs.

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The Threat of Gene Erosion

While the diversity of wild silkmoths is vast, it is fragile. The thesis highlights “gene erosion” as a critical threat to wild silkmoth conservation. This phenomenon refers to the gradual loss of genetic diversity due to the reduction of population sizes and the disappearance of unique genotypes.

Causes of Decline

1. Deforestation: The primary host plants—Sal (Shorea robusta), Arjun (Terminalia arjuna), and Asan (Terminalia tomentosa)—are forest trees. Indiscriminate felling and lopping for timber or fuel destroy the natural habitat of these moths.
2. Urbanization: Expansion of human settlements into tribal belts (the traditional rearing grounds) fragments the contiguous forests required for gene flow between moth populations.
3. Monoculture: The shift towards cultivating only commercially viable races (like Daba) risks the extinction of rarer, wilder races (like Raily) which hold genes for hardiness and disease resistance.

Fig: Impact of Deforestation on Wild Sericulture

Factor	Consequence for Silkmoths	Long-term Impact
Habitat Loss	Loss of breeding grounds and food	Extinction of local ecoraces
Forest Lopping	Scarcity of quality foliage	Poor cocoon weight & high mortality
Fragmentation	Isolation of populations	Inbreeding depression & weak offspring
Pesticide Use	Direct mortality of larvae	Collapse of local wild populations

Professor’s Insight: The “Raily” ecorace is a classic example of a conservation dilemma. It produces superior silk but refuses to be domesticated. If the Sal forests vanish, the Raily moth vanishes with them, taking its unique high-denier silk genes forever.

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Direct thesis quotes remain cited; remaining content is original and educational.

Conservation Strategies: In Situ and Ex Situ

To combat the decline of these valuable insects, the thesis advocates for a dual-approach to wild silkmoth conservation. This involves both protecting them in their natural habitat and creating artificial reserves.

In Situ Conservation (On-Site)

This involves protecting the silkmoths within their natural forest ecosystems.

• Seed Zones: Establishing protected forest areas where no commercial harvesting is allowed. These serve as “gene banks” where wild moths can breed naturally, maintaining their genetic purity.
• Forest Protection: Enforcing bans on the lopping of Sal and Asan trees in core tasar areas. The thesis notes that tribal communities must be integrated into this effort, balancing their livelihood needs with forest preservation.

Ex Situ Conservation (Off-Site)

This involves maintaining populations outside their natural habitat.

• Germplasm Banks: Systematic plantation of food plants (Economic Plantations) to rear specific silkworm stocks under controlled conditions.
• Grainage Management: Using scientific methods to preserve seed cocoons (pupae) during diapause to ensure healthy moth emergence for the next season. The thesis highlights the role of agencies like the Central Silk Board in maintaining distinct lines of A. mylitta.

Student Note: Germplasm refers to living genetic resources such as seeds or tissues (or in this case, fertilized eggs/pupae) that are maintained for the purpose of animal and plant breeding, preservation, and other research uses.

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Economic Zoology: Beyond Textiles

The conservation of wild silkmoths is not just about saving a species; it is about preserving an economic lifeline for millions of tribals and exploring medical applications. The thesis sheds light on the “non-textile” value of these insects.

Medical & Industrial Potential

• Biomaterials: Wild silk (especially from Antheraea species) is porous, unlike the compact Mulberry silk. This porosity makes it excellent for medical applications, including sutures and drug delivery systems.
• Health Benefits: The thesis references studies suggesting wild silk proteins may have roles in cholesterol control and alcohol metabolism in humans.
• UV Protection: Wild silk fabrics offer superior UV absorption compared to synthetic fibers or cotton, adding a “health” dimension to the textile.
• Waste Utilization: Even the cocoons that cannot be reeled (like those of Attacus atlas or pierced cocoons) are spun into “Ghicha” or “Katia” yarn, ensuring zero waste in the wild silk value chain.

Real-Life Applications

1. Forestry Policy: The data on host plant diversity supports the implementation of “mixed forestry” policies, planting Terminalia and Ziziphus alongside timber trees to support biodiversity.
2. Tribal Welfare Schemes: Conservation programs can be linked to employment guarantees (like MNREGA in India), paying locals to protect “seed zones” rather than harvest from them.
3. Ecotourism: The presence of giant moths like Attacus atlas (Atlas Moth) and Actias selene (Moon Moth) in the Western Ghats can be leveraged for butterfly/moth parks, promoting eco-tourism.
4. Pharmaceutical Research: Conserving diverse ecoraces ensures a genetic library for future bioprospecting, potentially leading to new silk-based biomaterials for surgery.

Why this matters: Conservation is not charity; it is an investment. Protecting the wild silkmoth ensures the stability of the Vanya silk industry, which sustains the poorest demographics in India.

MCQs

1. What is the primary cause of “gene erosion” in wild silkmoths as described in the thesis?
A) Excessive rainfall
B) Competition from Mulberry silkworms
C) Deforestation and urbanization
D) Bacterial diseases
Correct Answer: C
Difficulty: Easy
Explanation: The thesis explicitly identifies urbanization and the lopping of forests (deforestation) as the main drivers of gene erosion in wild non-mulberry flora and fauna.

2. Which ecorace of Antheraea mylitta is known for producing “stone-like” hard cocoons and is difficult to domesticate?
A) Daba
B) Raily
C) Sarihan
D) Laria
Correct Answer: B
Difficulty: Moderate
Explanation: The text describes the ‘Raily’ ecorace as Sal-based, univoltine, and producing hard, blackish cocoons that are difficult to rear in captivity.

3. Which of the following is an In situ conservation strategy for wild silkmoths?
A) Indoor rearing in plastic boxes
B) Establishing Germplasm banks
C) Creating protected Seed Zones in forests
D) Commercial grainage centers
Correct Answer: C
Difficulty: Moderate
*Explanation: *In situ* conservation means protecting the species in its natural habitat. Establishing protected seed zones in forests fits this definition.*

4. Why is the “porous” nature of wild silk filaments considered commercially significant?
A) It makes the silk cheaper to produce.
B) It allows for better dye absorption and comfort.
C) It makes the silk waterproof.
D) It prevents the silk from being spun.
Correct Answer: B
Difficulty: Challenging
Explanation: The thesis mentions that the porous structure of wild silk (Saturniidae) allows for better temperature/humidity regulation (comfort) and is suitable for fashionable clothing.

FAQs

Q: What is the difference between In situ and Ex situ conservation for silkmoths?
A: In situ conservation involves protecting silkmoths in their natural forest habitats (e.g., bio-reserves). Ex situ conservation involves maintaining them outside their natural habitat, such as in research institutes, grainages, or artificial plantations.

Q: Why are “ecoraces” important for the silk industry?
A: Ecoraces carry unique genetic traits (like disease resistance or hardiness) adapted to specific local conditions. Utilizing them allows for breeding stronger hybrids and ensuring silk production continues even in adverse climates.

Q: Does the Moon Moth (Actias selene) have commercial value?
A: While not as commercially exploited as Tasar, the thesis confirms that Actias selene produces a durable, lustrous silk. However, its primary value currently lies in biodiversity and potential “spun silk” markets.

Q: How does deforestation affect silk quality?
A: Deforestation forces rearers to use inferior or secondary food plants. The thesis shows that larvae fed on optimal hosts (like T. tomentosa) produce significantly heavier and silk-rich cocoons compared to those fed on poor-quality foliage.

Lab / Practical Note

Field Surveying: To assess wild silkmoth biodiversity, conduct “one man one hour” search surveys in forest pockets. Look for larvae on host plants, distinct cocoon peduncles hanging from twigs, or adult moths near light sources. Record the specific host plant for every specimen found, as this is crucial for identifying the ecorace.

External Resources

• Convention on Biological Diversity (CBD) – International standards for conserving genetic resources.
• Ministry of Textiles, Govt. of India – Policies regarding Vanya silk and tribal welfare.

Sources & Citations

Kavane, R. P. (2010). Biosystematics of wild silkmoths from Western Maharashtra. (Doctoral dissertation, Shivaji University, Kolhapur). 1-304.

Source Note: Information on ecoraces, conservation strategies, and gene erosion was sourced from Chapter I (Introduction) and the Review of Literature (Chapter II), specifically pages 23-29 and 38.

Correction Invitation: If you are the author of this thesis and wish to provide updates or corrections to this summary, please contact us at contact@professorofzoology.com.