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Molting in insects : Fresh skin every time

Molting, or the process of shedding old and degenerated skin for a new one in insects and animals, is a way of regeneration.

All insects have segmented bodies made up of many small sections. Insects have three major body divisions, the head, thorax and abdomen. Mouth-parts, eyes and antennae are found on the head, while legs and wings grow from the thorax. In some insects, these body divisions are easy to see, while in others, they are not so separate. The antennae are often long and carry sense organs for touch and smell. The head also has the usually large compound eyes and some ocelli or simple eyes. The head carries several pairs of mouth-parts, which are very important in distinguishing the insect order. Some are adapted for biting, with two mandibles, and some are modified to form a tube for sucking the liquid food. The thorax has legs and wings. The legs have spines and claws. The thorax carries a pair of wings. The wings are often colored and may have hairs or scales.

The outer covering of the insect is strengthened on all or some parts of the body by a hard cuticle, which protects the body, gives it a shape and as an external skeleton or exoskeleton provides a fixture for the soft body parts. This strengthened skin or cuticle consists of chitin and sclerostin. These two substances together form a very hard and resistant, but very light structure which in the course of evolution has served a variety of functions. Finally, the cuticle is covered by a waxy layer, which acts as water repellant. This very resistant and powerful form of skin has, however, one great disadvantage. Once formed it cannot be altered; that is, it can no longer grow. As the rest of the insect’s body grows, a new skin begins to form under the old one. When the insect molts, the old skin splits and the insect crawls out. The soft, new exoskeleton expands at first just like elastic, but once it has dried and hardened, it will not grow any longer. Some newly molted insects eat their old skins, other just leave them behind.

 

About the Author /

Yuwaraj Gurjar works with Raymond Limited - a renowned textile manufacturing company, but his love for nature always drives him to go places into wild India – being hugely diversified habitats. He has traveled across the country & Sri Lanka for nature observations and photography. His photographs have won many national and international awards; have been exhibited across the world. Some photos were included in field guides, educational websites and magazines. He actively spreads the awareness & knowledge about nature, wildlife & photography especially Macro Photography. He has developed a free Mobile App on Butterflies of Mumbai named “I love Butterflies”.

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