Question

Silk clothes are prepared from silkworms at which stage of its life cycle?
A) Fly
B) Pupa
C) Larva
D) Egg

Answer 1

Hint:Silkworms are the caterpillar stage of the silk moth, Bombyx mori. They feed on the leaves of the white mulberry plant though they can also feed off the red plant. Occasionally, in the absence of either, silkworms can feed on the Osage orange.

Complete answer:
Like any member of the moth family, the silk moth goes through several stages, including a larval and pupal stage. The female moth lays about 300-500 eggs on the leaves of the mulberry tree. When the caterpillars hatch, they immediately begin feeding on the leaves. Starting off at a bare 2-3 mm in length, over a period of 45 days these caterpillars grow to 75mm. They feed continuously through the day to support this growth. At this point, pupation begins and the caterpillars spin a cocoon made out of a continuous thread of silk that they secrete from a special gland. This thread is usually more than 900 metres in length. Adult silk moths have lovely cream-coloured wings.

 Let us look into the given options
>To extract the silk thread, the pupa are steamed to kill them and soften the cocoon, and the silk is then extracted as one intact fibre. Option B is the correct answer.
>Silkworms are not members of the fly family, but are lepidopterans. Option A is incorrect.
>The caterpillars are the larval stage of the silk moth. These form the pupa. Option C is incorrect.
>Eggs cannot produce silk, therefore option D is incorrect.

Hence the correct answer is option ‘B’

Note:Interestingly, having been cultivated for thousands of years, the silk moth used for sericulture is now no longer found in the wild, only in silk factories. As with many lepidopterans, the larval form has teeth, but the adults do not feed at all.