Model Answer
0 min readIntroduction
*Bombyx mori*, the domesticated silkworm, is central to the sericulture industry, providing the raw material for silk production. Understanding its life cycle is crucial for optimizing silk yield and quality. The life cycle of *Bombyx mori* is a complete metamorphosis, progressing through four distinct stages: egg, larva, pupa, and adult moth. Each stage is characterized by specific morphological and physiological changes essential for the continuation of the species and silk production.
The life cycle can be represented as follows:
Stages of Life History:
1. Egg Stage:
Small, oval, and initially pale yellow, turning grayish before hatching. Incubation lasts approximately 10-14 days depending on temperature.
2. Larval Stage (Instars):
The larva (caterpillar) undergoes five instars, separated by molts. During each instar, the larva voraciously consumes mulberry leaves, increasing in size and weight. This stage lasts around 20-30 days.
3. Pupal Stage (Cocoon Formation):
The larva spins a cocoon made of silk fibroin, a protein secreted from its silk glands. This stage lasts about 10-14 days. Inside the cocoon, the larva transforms into a pupa.
4. Adult Moth Stage:
The adult moth emerges from the cocoon. Adult moths are incapable of flight and their primary function is reproduction. Females lay approximately 300-500 eggs before dying. The entire life cycle takes about 45-60 days.
Conclusion
The life cycle of *Bombyx mori* is a fascinating example of complete metamorphosis, intricately linked to silk production. Understanding each stage – from the tiny egg to the reproductive adult – is vital for successful sericulture practices. Optimizing conditions for each stage, particularly the larval stage, directly impacts the quantity and quality of silk produced, making it a cornerstone of the textile industry.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.