I remember as a child when my aunt, an agricultural engineer, once brought me a handful of silkworms. My father and I used to bring them mulberry leaves from a tree in our neighborhood. It was such a relaxing amusement to watch their rhythmic and consistent feeding movements.
Now that I have grown up, I realize what was so inspiring about these small creatures: they lead a very disciplined life and achieve their goals in a timely manner. Like bees, they have been of significant economic value to humans, which is becoming greater everyday thanks to non-stop technological advancements.
Silkworm Life-Cycle
The Silkworm Lifecycle
The lifecycle of silkworms typically spans between 45 to 55 days. During the larva or caterpillar phase, which continues through 24–28 days, the worms focus on one mission: nutrition. They consume mulberry leaves voraciously at an astonishing rate to get the nutrients needed to spin their cocoons.
Eventually, the fully-grown larva will spin a cocoon around itself using a silk strand it secreted from glands in its mouth. This process continues for a few days and the strand can reach up to 915 meters long. The result is a marvel of architecture, structured out of an economically valuable material. Inside the safe and sturdy cocoon, the caterpillar pupates.
It takes around 8 to 10 days for the pupa to turn into the last phase: the mature moth. The female moth only lives for 3 or 4 days, and dies after laying 300–500 eggs. The eggs hatch within one or two weeks depending on the temperature, and the tiny larvae start the cycle all over again.
Sericulture: A Brief History
Attributed to Liang Kai
Cleveland Museum of Art.
Before around 4000 years, the Chinese managed to unwound the silkworm cocoon and wove it into a valuable fabric we still use until today: silk. Very soon, the sericulture became an important feature of the Chinese rural economy.
As a matter of fact, the popular Eurasian caravan routes, known as the Silk Road, derived its name from the flouring trade of the silk textiles that were exclusively produced in China. It was not before the mid-first millennia CE that the sericulture secrets found its way to Europe. Then, it gradually spread around the world, to reach the Americas in the early 1600s.
Most of the current production of silk relies mainly on the mass cultivation of domesticated silkworms.
Sericulture: Future Potential
Commonly known as the queen of textiles, silk is elegant, soft, and durable. Yet, technological advancement never fails to make things better. Although both kinds of natural silks are known for their strength, spider silk is at least two times stronger than silkworm. However, spiders produce silk in much lesser amounts than the silkworms, mainly to build prey-hunting webs, which makes commercialized production very difficult.
In a recent study published in September 2023, a team from Donghua University, China, led by researcher Junpeng Mi, found a way to bring together the advantages of spider silk and the production mechanism of silkworms . Using the state-of-the-art gene-editing tool, CRISPER/Cas9, the team inserted the complete instructions for making spider silk protein into silkworms. According to the researchers, the resulting fabrics “offer promising potential as sustainable alternatives to synthetic commercial fibers”.
Silkworms life cycle from egg to moth in one minute
References
britannica.com/animal/silkworm-moth
britannica.com/topic/silk
cell.com
everythingsilkworms.com.au
bibalex.org/SCIplanet
hts.assam.gov.in
mansfieldct-history.org