Overview of Secretion Animals Insects

by Elizabeth / Thursday, 29 July 2021 / Published in Sericulture

Insects have developed remarkable strategies for survival, and among these, silk production stands out as a fascinating example of biological ingenuity. From constructing protective cocoons to crafting intricate webs, various insects utilize silk for a multitude of purposes. This article delves into the world of insect secretions, focusing on silk and its significance in the lives of these creatures.

1. The Purpose of Silk Secretion in Insects

Insects secrete silk primarily for protection, movement, and reproduction. When a silkworm larva transitions into a pupa, it spins a cocoon to shield itself from environmental threats and predators. Similarly, other insects might use silk for molting, nesting, and escaping danger. Spiders, though not insects, famously use their silk to construct webs for capturing prey. These examples underscore the critical role of silk in insect survival, demonstrating a biological adaptation refined over millennia.

2. Understanding Silkworm Silk

Silk is essentially a protein fiber produced, secreted, and spun by certain insects. The silkworms raised commercially for their cocoons belong mostly to the Lepidoptera order, encompassing families like Bombycidae and Saturniidae. Here are some noteworthy silkworm species:

Species	Scientific Name	Family	Characteristics
Domestic Silkworm	Bombyx mori	Bombycidae	Most widely cultivated for silk production
Oak Silkworm	Antheraea pernyi	Saturniidae	Produces a coarser silk, often used in textiles
Celestial Silkworm	Antheraea yamamai	Saturniidae	Known for producing a fine, luxurious silk
Eri Silkworm	Philosamia cynthia ricini	Saturniidae	Produces open-end cocoons, often used for spun silk
Tussah Silkworm	Antheraea mylitta	Saturniidae	Produces a strong, textured silk
Muga Silkworm	Antheraea assama	Saturniidae	Known for its golden-colored silk

3. Other Silk-Producing Insects

Besides the commercially cultivated silkworms, several other insects within the Bombycidae family also produce silk. These include:

Wild Silkworm (Bombyx mandarina): A wild relative of the domestic silkworm.
Mulberry Butterfly (Rondotia menciana): A silkworm species that feeds on mulberry leaves.
Himalayan Wild Silkworm (Theophila huttoni): Another wild silkworm species.

Chinese Tussah Silkworm

Moreover, the moth family includes various species known by names such as Giant silkworm, Wild silkworm, and Day-flying moths, many of which also produce silk. Some notable examples are:

Camphor Silkworm (Eriogyna pyretorum): Larvae feed on camphor, maple, and chestnut leaves and are often used for fishing lines.
Chestnut Silkworm (Dictyoploca japonica): The larvae of this silkworm feed on chestnut, camphor, ginkgo, and walnut leaves, creating a brown cocoon.
Ubai Silkworm Moth: Known as the “King of Moths,” this species can have a female adult with a wingspan of up to 27cm.

4. Silk Production in Spiders

While not insects, spiders also secrete silk, demonstrating a different form of silk application. Orb-weaving spiders, for example, have up to seven different types of silk glands, which each synthesize different silk proteins. These multiple spinning tubes at the end of the abdomen allow for the production of silks with different properties, suitable for various parts of the web and specific functions. Spiders’ ability to produce and manipulate different silks highlights the versatility of silk as a material.

Spider Silk

5. Conclusion

The ability of insects to secrete silk is a remarkable evolutionary adaptation, offering protection, aid in movement, and help in reproduction. From the cocoons of commercially cultivated silkworms to the intricate webs of spiders, silk serves a multitude of purposes. Studying these secretions not only sheds light on the complexity of nature but also provides a deeper understanding of the ways that organisms adapt to thrive in their environment.