The silkworm is a small animal known to most of us for its great contribution to the world of fashion through the natural production of silk.
But what is its story?
Who is this great silk producer of all time?
Strange as it may seem, the silkworm is actually the larva of a small moth belonging to the Bombicidae family.
So we are talking about a real lepidopteran!
In short, it's a butterfly!
This group, although extremely important in the global production of many of our favourite items of clothing, is actually very small for an insect family.
In fact, it contains only In fact, it contains only 300 species, an extremely small number when we consider orders (groups) of insects such as the Coleoptera, with 392,415 species,, numero estremamente piccolo se consideriamo ordini (gruppi) di insetti come i Coleotteri con le loro 392.415 specie
or the Hymenoptera (wasps, hornets, bees, bumblebees and ants), with 100,000 species!
Returning to our Bombicidae, Bombyx mori, the adult of what we know as the silkworm, is the only Lepidoptera species that has been completely domesticated by man and bred on an industrial scale.
This small, productive moth no longer exists in the wild, but has been turned into a productive tool, losing all of its wild characteristics over time.
Terrible, eh?
But let us discover the origins of the silkworm
The evolution and history of the silkworm has always gone hand in hand with the evolution of human civilisation, starting with Chinese civilisation.
In fact, it is on Chinese soil that we have the first evidence of intensive breeding of this small larva, which led to an explosion in silk production only in 2600 BC,
the year in which this industry dominated the entire Chinese continent.
It was during this period, and with this great "domestication" of the silkworm,
that the poor moth had to give up all its wild characteristics in order to submit completely to the great global fashion market.
In fact, although the origin of the market is certainly Chinese, the use of this poor species was very quickly established in world production!
The silkworm is not the only animal that can fascinate us, even if we do not know everything about it!
In the animal and plant world there are so many wonders hidden behind behaviours, shapes and colours that we, as humans, do not always understand.
That is why I have decided to dedicate an entire section to the other creatures that inhabit our planet.
I am waiting for you!
A short life for the silkworm
Bombyx mori has a life cycle that, although short in our eyes, encompasses all possible life stages in the environmental world.
In fact, its entire life cycle is divided into four stages.
1. The egg:
the life of a young butterfly is always the result of some activity on the part of the adult female.
In this case, it is oviposition, or more precisely, the laying of eggs by the female on mulberry leaves, the moth's favourite food.
Black mulberry or white mulberry, the moth makes no difference!
So it is on the leaves of this fragrant plant that the adult female lays small, spherical, white eggs that take a good 10 to 12 days to hatch.
2. The larva:
after 12 days the eggs will hatch into small larvae and then into the well known and much loved silkworms!
These small larvae, initially black in colour, will begin to feed on mulberry leaves.
This activity allows them to grow in size in a short time.
This larval stage, during which the silkworms will devote their time to growth, lasts about 30 days.
During this time, the larvae must shed their skin up to four times before moving on to the next stage of development.
3. Pupa:
and we are now in the developmental stage following the fourth moult of the larvae.
They are ready to pupate!
And there they are, in the midst of their activity, dedicated to the creation of their warm and comfortable silk cocoon.
How do they manage to create this miracle of nature that is the cocoon?
Well, for them it is very simple: they use glands (called 'sericin glands') which, together with four openings at the sides of their mouths,
release a thin slime which, when it comes into contact with air, solidifies to form a long silk fibre!
And slowly the cocoon, made of a single continuous thread of silk, takes shape, completely enveloping the larva in no more than 14 days!
4. Adult:
after 14 days of warmth and comfort inside the cocoon, the pupa emerges as an adult moth.
The adults of this species are actually small moths with a wingspan of about 4 cm, nothing more!
Furthermore, unlike all previous stages, where the main purpose is to feed,
adults have no reason to eat, and for this very reason their mouthparts are completely atrophied.
Their only motivation in life is to mate and lay eggs.
Once even these two activities are completed within a few days, the adults die and a new life cycle begins for their young!
The silkworm and its strict diet
We saw a few paragraphs ago how the life of the silkworm has been dependent on global trade and production for several centuries.
This even applies to its diet.
The diet must be costant and regular in order for the silk producers to be able to produce excellent, high quality silk at all times.
Any deficiency or change in the quality of the black mulberry or white mulberry leaves may in fact damage the growth of the larvae or produce a lower quality of silk.
The diet of this species is mainly based on mulberry leaves, so breeders try to provide the silkworm with fresh, clean leaves.
Over the centuries, the silkworm has become a key player in the development of the human economy.
Its 'domestication' has enabled man to develop a world-class industry, creating a valuable textile product that, after centuries, is still synonymous with high quality.
But it is also a living being, like all of us, with a particularly complex evolutionary dynamic, its own life cycle and its own needs.
Are we so sure that we still want to see it as a mere tool for production and profit?
EN 
IT
Leave a Reply