Care guide
What a Silkworm Is Worth: Every Part, Accounted For
An Accounting
Most farmed animals yield one or two things. A silkworm has been made to yield at least six, and the list is still growing. Set out together it is a genuinely unusual inventory.
The Cocoon → Silk
The obvious one. One continuous filament, reeled with others into thread. Five thousand years of the entire industry.
The Coating → Cosmetics
Sericin, discarded for centuries into wastewater at something like 50,000 tonnes a year, now in creams and shampoos for hydration, elasticity and protection against bleaching damage.
The Pupa → Food
About 60% of cocoon weight, 18 amino acids, mainly unsaturated fat, eaten across Asia and used in Chinese traditional medicine.
The Droppings → Fertiliser
Frass raises crop yield, soil organic matter and soil enzyme activity.
The Gland → Fishing Line
For centuries the finest fly-fishing leader in the world was silkworm gut — the silk gland itself, drawn out and dried. An industry in Murcia existed to supply it.
The Fibroin → Medicine and Electronics
Sutures since 500 BC and still FDA-approved. Tissue scaffolds and drug delivery. Sensors and memory devices designed to biodegrade.
The Animal Itself → Research
A validated infection model for screening antibiotics, a model organism with a sequenced genome, the animal in which the first pheromone and an insulin-like peptide were found — and, engineered, a factory for recombinant human proteins.
The Pattern
Every one of these began as a by-product somebody was throwing away. The history of the silkworm is largely a history of people slowly noticing that the parts they discarded were worth more than the disposal.
Related: how silk is reeled · sericin in cosmetics