---
title: "What the sources say about the Silkworm | AnimalTracks.wiki"
description: "31 claims from the Silkworm profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/silkworm-1.webp"
canonical: "https://animaltracks.wiki/animals/silkworm/sources/"
---

# What the sources say about the Silkworm (*Bombyx mori*)

> 31 claims from the Silkworm profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Silkworm](https://animaltracks.wiki/animals/silkworm/)

## The silkworm (Display board 5, C'era una volta un filo di seta). Fondazione Museo Civico di Rovereto.

https://fondazionemcr.it/silk05-the-silkworm

| The page says | The source says |
| :--- | :--- |
| A caterpillar that grows thousands of times heavier in a month, then wraps itself in one silk thread up to 1,800 metres long. | over the period of a month, the larva has grown by 30 times its length and 9,000 times its weight ... The cocoon is made from a single, highly resistant thread which can be as long as 1,800 metres. (note: tagline) |
| no longer found in the wild | no longer exists in a wild state |
| Mulberry leaves as a larva; the adult moth does not feed | In its larval stage this lepidopteran feeds exclusively on mulberry leaves ... The adult insect does not feed (note: stats.diet) |
| Spins a single silk thread up to 1,800 metres long | The cocoon is made from a single, highly resistant thread which can be as long as 1,800 metres. (note: stats.superpower) |
| A silkworm is the caterpillar of the silk moth Bombyx mori. | Silk is produced by the larva of the Bombyx mori moth |
| A newly hatched larva (the caterpillar stage) is dark, about 3 millimetres long and weighs about half a milligram. | When just born the larva is dark, about 3 millimetres long and weighs about half a milligram. |
| On the figures of the silk museum display in Rovereto, Italy, it reaches 9 cm and 4 grams in about a month, growing 30 times longer. | At its greatest size, the larva reaches 9 cm and weighs 4 grams. Therefore, over the period of a month, the larva has grown by 30 times its length (note: scoped to the Rovereto board because the 2022 Iraq study's fifth-instar mean (5.25 g) exceeds its 4 g maximum) |
| The growth comes in stages separated by moults, also known as sleeps. | takes place in stages separated by moults also known as sleeps |
| The larva feeds on mulberry leaves. | In its larval stage this lepidopteran feeds exclusively on mulberry leaves |
| In the farmhouse kitchens around Rovereto where silkworms were once raised, the noise of their jaws just before they climbed to spin grew into a continuous, deep rumble that made the whole house vibrate | In the big kitchens of these farmhouses ... In the period immediately preceding their climb to the mountages, the silkworms became more and more ravenous. The noise of their jaws grew to become a continuous, deep rumble which made the whole house vibrate ... once so important for the local economy (note: farmhouse kitchens: 'In the big kitchens of these farmhouses, after the eggs hatched, the larvae were looked after') |
| Silk comes from two glands beneath the larva's mouth. | The silk is produced by the larva through two glands beneath its mouth. |
| After four moults, the larva's torpor gives way to a period of agitation known as "fury", and it tries to climb to find a support on which to attach its cocoon. | After four moults, the torpor of the larva stage alters into a period of agitation and movement known as "fury", and the larva tries to climb to find a support on which to attach its cocoon. |
| The cocoon is made from a single, highly resistant thread that can be as long as 1,800 metres. | The cocoon is made from a single, highly resistant thread which can be as long as 1,800 metres. |
| In three or four days the larva has completely wrapped itself in silk and turns into a chrysalis. | In three or four days the larva has completely wrapped itself in silk and turns into a chrysalis. |
| Bombyx mori originated in east central Asia and no longer exists in a wild state. | the Bombyx mori moth originating in east central Asia ... no longer exists in a wild state |
| Its whole life cycle is complete in approximately 45 days. | Its life cycle is completed in approximately 45 days. |
| The adult moth does not feed, and its only duty is to ensure the conservation of the species. | The adult insect does not feed and its only duty is to ensure the conservation of the species. |
| Silk is made of two very fine filaments of a protein called fibroin, which does not dissolve in water. A sticky coat of another protein, sericin, covers both strands. | two very fine filaments of a protein substance called fibroin, not soluble in water. The two filaments/strands are coated with a sticky sheath of a protein called sericin. |
| The larva feeds exclusively on mulberry leaves. The adult moth does not feed at all. | In its larval stage this lepidopteran feeds exclusively on mulberry leaves ... The adult insect does not feed |
| One thread, 1,800 metres long | The cocoon is made from a single, highly resistant thread which can be as long as 1,800 metres. (note: heading) |
| In the farmhouses around Rovereto, the noise of silkworm jaws grew into a continuous, deep rumble that made the whole house vibrate. | In the big kitchens of these farmhouses ... In the period immediately preceding their climb to the mountages, the silkworms became more and more ravenous. The noise of their jaws grew to become a continuous, deep rumble which made the whole house vibrate ... once so important for the local economy (note: vibe.reason; reuses the body claim) |

## Mohammed & Ayoub (2022). Biology and Behavior of Mulberry Silkworm (Bombyx mori) in Northern Iraq. ISPEC Journal of Agricultural Sciences, FAO AGRIS record.

https://agris.fao.org/search/es/records/6851867daab9439e79fcfa26

| The page says | The source says |
| :--- | :--- |
| Strains differ: in a 2022 rearing study in northern Iraq, final-stage larvae averaged 5.25 grams. | Biology and Behavior of Mulberry Silkworm (Bombyx mori) in Northern Iraq 2022 ... The durations of larval instars (1st, 2nd, 3rd, 4th, 5th) ... Average weight of 4th and 5th instars larvae were 3.45 ± 0.90 g and 5.25 ± 1.25 g respectively (note: fifth instar is the final one (five instars listed); 'strains differ' because this is the Bursa White strain against the Rovereto board's 4 g) |
| Cocoons in the Iraq study weighed 1.7 to 2.5 grams each. | Biology and Behavior of Mulberry Silkworm (Bombyx mori) in Northern Iraq 2022 ... Weight of a single cocoon was 1.7 to 2.5 gm (note: 2022 study in northern Iraq, Bursa White strain) |
| The Iraq study set out to revive rearing there after three decades without it, using silkworms imported from a sericulture centre in Bursa, Turkey. | This study was aimed to revive the neglected valuable insect in Iraq after its absent for three decades ... Bombyx mori (Bursa White; ‘Bursa Beyazi’) were imported from Sericulture Center in Bursa, Turkey. |
| In a 2022 rearing study in northern Iraq, adult males lived an average of 115 hours and adult females 135.5 hours. | Biology and Behavior of Mulberry Silkworm (Bombyx mori) in Northern Iraq 2022 ... Adult male longevity was 115.00 ... adult female longevity was 135.50 (note: 'average' is the mean in the +/- format) |

## Bombyx mori. Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Bombyx_mori/

| The page says | The source says |
| :--- | :--- |
| Not Evaluated | Bombyx mori is currently not an endangered or threatened species ... IUCN Red List [Link] Not Evaluated (note: stats.conservationStatus. GBIF's Red List copy holds no category for Bombyx mori and the prefetch found no assessment DOI, so no IUCN reference is cited. The ADW page lists the species as Not Evaluated.) |

## Tong et al. (2022). High-resolution silkworm pan-genome provides genetic insights into artificial selection and ecological adaptation. Nature Communications.

https://doi.org/10.1038/s41467-022-33366-x

| The page says | The source says |
| :--- | :--- |
| Reared by people for silk | the domestic silkworm ( B. mori ) is a completely domesticated economic insect entirely dependent on humans for survival (note: stats.habitat; 'for silk' is the economic use the Rovereto board describes (Silk is produced by the larva of the Bombyx mori moth); the no-longer-wild half is the Rovereto claim below. The ADW 'silk industry in Asia and Australia' line was dropped: page last updated 2001, citing Savela 1998) |
| It was domesticated from its wild ancestor, Bombyx mandarina, about 5,000 years ago. | was domesticated from its wild ancestor, B. mandarina , ~5000 years ago (note: ~5000 years ago written as about 5,000) |
| Compared with its wild ancestor, the domestic silk moth has lost the ability to fly. | behavior differences between B. mori and B. mandarina , such as larval ability to withstand crowding and handling, relatively docile feeding (without a strong drive for finding food), and loss of flight ability (note: 'wild ancestor' is B. mandarina per the domestication claim above (same paper); flight is an adult trait) |
| A genome study calls the domestic silkworm a completely domesticated insect that is entirely dependent on humans for survival. | the domestic silkworm ( B. mori ) is a completely domesticated economic insect entirely dependent on humans for survival |

## Hybrid silkworms spin stronger spider silk. University of Notre Dame College of Science.

https://science.nd.edu/news/34100-hybrid-silkworms-spin-stronger-spider-silk/

| The page says | The source says |
| :--- | :--- |
| Genetically engineered silkworms carrying both silkworm and spider silk proteins spun fibres tougher than normal silkworm silk and as tough as the dragline silk spiders make, according to a 2012 report from the University of Notre Dame. | Published: January 06, 2012 ... transgenic silkworms with both silkworm and spider silk proteins ... Results showed that the fibers were tougher than typical silkworm silk and as tough as dragline silk fibers produced by spiders |