Question

Define the correct route for the life cycle of silk worm from the following
A. Eggs, Larvae, pupa and adult silkworm.
B. Eggs, pupa, Larva and adult silkworm.
C. Eggs, Larva, cocoon, pupa and adult silkworm
D. Eggs, Larva, cocoon and adult silkworm.

Answer 1

Hint:- Life cycle is defined as the series of developmental changes that members of a species pass through till the inception of the same beginning developmental stage in the next generation. Silk worm belongs to the insecta and is the caterpillar or larva of a silk moth. To answer this question, let us understand the various developmental stages of the silk moth and based on that, we will try to find the most suitable answer.

Complete Answer:-Let us first know about the various developmental stages of the silk moth.
There are mainly four developmental stages in the life cycle of a silkworm. They are-
Eggs- the life cycle begins with the laying of eggs by female moth in the summer. The eggs so laid remain dormant upto spring allowing the hatching of the eggs. Protection to the embryonic development is provided by the egg shell.
Larvae- known as the silkworm and is a vegetative stage where silkworms feed on smooth mulberry leaves. It includes 5 growth stages called instars and generally lasts for about 27 to 30 days.
 Pupa- in this stage, a protective silk thread called cocoon is weaved by the larva around itself. Final moulting takes place inside the cocoon to convert lava into brown, chitinous structure called pupa.
Adult silk moth- Imago is the adult stage where female moths lay eggs after mating and thus mark the beginning of the life cycle of silkworm again.

From the above discussion, it is clear that the correct answer is (A)- Eggs, Larvae, pupa and adult silkworm.

Note:- Pupa can be killed as the cocoon is plunged into boiling water and unwinding of silk thread is done. Silk moths differ from most of the members of their genera due to incapability of adult moths to fly and also because of the lack of colour pigments and functional mouthparts.