Chinese Tallow Silkworm (Attacus Atlas Linnaeus)

The Attacus atlas, often called the Chinese Tallow Silkworm or the “King of Moths,” is a remarkable insect renowned for its massive size and its silk-producing capabilities. This moth provides a unique type of silk, known for its strength and durability, and plays a significant role in traditional textile production in certain regions.

1. Geographical Distribution and Life Cycle

The Attacus atlas is widely distributed across Southeast Asia and parts of China. Specifically, in China, it is found mostly in mountainous areas of southern provinces, including Guangdong, Guangxi, and Fujian, with sightings in other provinces like Jiangxi, Sichuan, Yunnan, and Taiwan. The moth typically undergoes 2 to 3 generations annually, overwintering in the pupal stage. The breeding season spans from April to November, with non-diapause pupae completing their development in about 30 days and diapause pupae requiring 155-170 days.

2. Physical Characteristics of the Adult Moth

The adult Attacus atlas is a sight to behold, boasting a wingspan of 25 to 30 cm, earning it the title “King of Moths.” Key physical traits include:

• Wing Shape: Sickle-shaped wingtips with prominent curved edges.
• Coloration: Head, thorax, and abdomen are russet in color.
• Wing Markings: A distinctive triangular transparent marking in the center of each wing, edged in black and then light red to purple-brown. Yellow-brown outer edges with wavy black lines.
• Eye Pattern: A noticeable eye pattern is present on the top of the forewings.

3. Mating and Egg Laying Habits

Adult Attacus atlas moths are nocturnal, mating at night and laying eggs the following evening. Each female typically deposits around 200 eggs over two nights on branches and leaves of suitable host plants.

4. Larval Development and Behavior

Attacus atlas larvae undergo 6 or 7 instars before pupation. These caterpillars are not gregarious, particularly the 5th instar, which is solitary, slow-moving, and exhibits a strong grip using its gastropods and tail feet. Final instar larvae are about 11 cm long, exhibiting a blue and milky white coloration. Mature larvae often rest for 1 to 2 days before constructing their cocoons.

5. Cocoon Characteristics and Silk Production

The silkworms create oval-shaped, brown cocoons, with spring cocoons being larger than those made in the autumn. The average cocoon measures about 8 cm long and 3 cm wide.

The silk produced by the Attacus atlas is notably strong and has good elongation properties. After degumming, the silk can be spun. The spun silk, traditionally known as ““水紬” (water spun silk), is known for its exceptional durability.

6. Larval Diet

The larvae of the Attacus atlas are polyphagous, feeding on the leaves of various plants. Among the most favored are coral leaves and Chinese tallow leaves. Other plants include Niu’er maple, holly, camphor, maple, poplar, sand pear, barnyard tree, Liquidambar formosana, and Qianjin elm.

The Attacus atlas silkworm stands as a unique example of nature’s ingenuity, providing a robust silk material while exhibiting incredible biological traits. Its ecological and traditional importance make it a fascinating subject of study and a valuable resource.