Life Cycle of Bombyx mori — PPT Note 1. Introduction Scientific name: Bombyx mori Linnaeus, 1758 Common name: Mulberry silkworm / Domestic silkworm Order: Lepidoptera Family: Bombycidae Bombyx mori is one of the most economically important insects because its larva produces commercial silk. It is a completely domesticated insect and depends largely on humans for its maintenance and reproduction. � Research Journals The life cycle shows complete metamorphosis (holometabolous development) with four major stages: Egg → Larva → Pupa → Adult moth Only the larval stage is actively feeding. � MDPI Slide 1 — Title LIFE CYCLE OF BOMBYX MORI Mulberry Silkworm Scientific name: Bombyx mori Order: Lepidoptera Family: Bombycidae Importance: Production of natural silk Presentation focus: Development from egg to adult moth. Slide 2 — General Life Cycle Use a circular diagram: Adult moth ↓ mating & oviposition Egg ↓ hatching Larva / Silkworm ↓ moulting & feeding Cocoon formation ↓ pupation Pupa ↓ metamorphosis Adult moth The four fundamental developmental stages are egg, larva, pupa and adult. � MDPI Key point Bombyx mori undergoes complete metamorphosis, because the larva and adult are morphologically and functionally very different. Slide 3 — Egg Stage Egg / Embryonic stage The life cycle begins when the female moth lays eggs after mating. Important features Eggs are very small and generally round/oval and flattened. Newly laid eggs are generally pale or creamy yellow. Fertile eggs progressively become dark grey/blackish during development. Embryonic development occurs inside the egg. Under suitable conditions, hatching generally occurs in approximately 7–14 days. The newly hatched larva is small, dark and hairy. � Research Journals +1 Special point In some races, the egg may undergo diapause, in which embryonic development temporarily stops. This is important in seasonal management of silkworm races. Slide 4 — Larval Stage Larva — the silkworm The larval stage is the most important stage from the viewpoint of silk production. After hatching, the larva feeds mainly on mulberry (Morus) leaves and undergoes rapid growth. The larva passes through five instars separated by four moults. � Research Journals Sequence 1st instar → Moult → 2nd instar → Moult → 3rd instar → Moult → 4th instar → Moult → 5th instar During this period: Body size increases greatly. Feeding activity increases. Silk glands develop enormously. Larval cuticle is periodically shed. The final instar prepares for cocoon formation. Slide 5 — Five Larval Instars Instar Approximate duration* 1st instar 3–4 days 2nd instar 2–3 days 3rd instar 3–4 days 4th instar 4–5 days 5th instar 6–7 days *Approximate values under favourable rearing conditions; actual duration varies among races and environmental conditions. � Research Journals Important observation The fifth instar is particularly important because the mature larva develops a highly active silk gland and accumulates resources before spinning the coc
Life Cycle of Bombyx mori — PPT Note 1. Introduction Scientific name: Bombyx mori Linnaeus, 1758 Common name: Mulberry silkworm / Domestic silkworm Order: Lepidoptera Family: Bombycidae Bombyx mori is one of the most economically important insects because its larva produces commercial silk. It is a completely domesticated insect and depends largely on humans for its maintenance and reproduction. � Research Journals The life cycle shows complete metamorphosis (holometabolous development) with four major stages: Egg → Larva → Pupa → Adult moth Only the larval stage is actively feeding. � MDPI Slide 1 — Title LIFE CYCLE OF BOMBYX MORI Mulberry Silkworm Scientific name: Bombyx mori Order: Lepidoptera Family: Bombycidae Importance: Production of natural silk Presentation focus: Development from egg to adult moth. Slide 2 — General Life Cycle Use a circular diagram: Adult moth ↓ mating & oviposition Egg ↓ hatching Larva / Silkworm ↓ moulting & feeding Cocoon formation ↓ pupation Pupa ↓ metamorphosis Adult moth The four fundamental developmental stages are egg, larva, pupa and adult. � MDPI Key point Bombyx mori undergoes complete metamorphosis, because the larva and adult are morphologically and functionally very different. Slide 3 — Egg Stage Egg / Embryonic stage The life cycle begins when the female moth lays eggs after mating. Important features Eggs are very small and generally round/oval and flattened. Newly laid eggs are generally pale or creamy yellow. Fertile eggs progressively become dark grey/blackish during development. Embryonic development occurs inside the egg. Under suitable conditions, hatching generally occurs in approximately 7–14 days. The newly hatched larva is small, dark and hairy. � Research Journals +1 Special point In some races, the egg may undergo diapause, in which embryonic development temporarily stops. This is important in seasonal management of silkworm races. Slide 4 — Larval Stage Larva — the silkworm The larval stage is the most important stage from the viewpoint of silk production. After hatching, the larva feeds mainly on mulberry (Morus) leaves and undergoes rapid growth. The larva passes through five instars separated by four moults. � Research Journals Sequence 1st instar → Moult → 2nd instar → Moult → 3rd instar → Moult → 4th instar → Moult → 5th instar During this period: Body size increases greatly. Feeding activity increases. Silk glands develop enormously. Larval cuticle is periodically shed. The final instar prepares for cocoon formation. Slide 5 — Five Larval Instars Instar Approximate duration* 1st instar 3–4 days 2nd instar 2–3 days 3rd instar 3–4 days 4th instar 4–5 days 5th instar 6–7 days *Approximate values under favourable rearing conditions; actual duration varies among races and environmental conditions. � Research Journals Important observation The fifth instar is particularly important because the mature larva develops a highly active silk gland and accumulates resources before spinning the coc
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This overview delves into the life cycle of Bombyx mori, highlighting the significance of silk. It outlines the complete metamorphosis from egg to adult, detailing egg characteristics, larval development through five instars, and the crucial role of mulberry feeding. The silk production process is examined, including cocoon formation and its impact on yield, supported by a comparative chart of instar durations. Key takeaways emphasize the connection between larval care and silk quality.