- Egg
- Larva
- Pupa
- Adult
- Small, flat on ventral side, ellipsoidal or oval in shape.
- Size & shape: About 1-1.3mm in length,0.9-1.2 mm in width.
- Weight: Approx. 0.55-0.6mg.
- Newly laid eggs are white to pale yellow (non hibernating type) initially & dark brown subsequently (hibernating type).
- Micropyle is present at the anterior end.
- Egg shell is transparent, with a protective covering named chorion.
- Numerous funnel shaped respiratory canals are distributed over entire surface to allow air exchange.
- Arrangement: Deposited stuck together on the substrate.
- Distinctly segmented body divided into head, thorax, and abdomen.
- Size and Appearance: Newly hatched larvae measure about 4 to 6 mm in length and are initially yellowish-white to grayish. Fully grown larvae reach about 6 to 8 cm in length, with a wrinkled, hairless, and smooth body.
- Coloration: The larva is generally pale buff or white, often becoming transparent and golden light brown by the final instar.
- Head is small & covered with brown chitin.
- Head bears mandibulate (biting) mouthparts,3 segmented antennae and three pairs of simple eyes (ocelli).
- A distinct hook-like spinneret (silk-spinning organ) is located on the mouth region, used for producing silk threads.
- Thorax is 3 segmented, each bears a pair of jointed legs on the ventrolateral sides.
Brown markings are present on the thoracic segments.
Prothorax has a pair of spiracles on the lateral sides.
Mesothorax has eye spots on the dorsal surface.
Abdomen has 11 segments with 8 pairs of spiracles,4 pairs of abdominal legs, a pair of caudal legs and one caudal horn.
The larva undergoes five growth stages called instars, molting four times.
In males, a spot called Herold's imaginal bud is situated on the ventral side between 8th & 9th segments.
In female, a pair of spots, Ishiwata's imaginal buds, are situated on the ventral side between 8th & 9th segments.
Silk Glands: Large lateral silk glands develop in the 4th and 5th instars, producing silk to spin the cocoon.
Brown, chitin-covered, almost motionless stage enclosed within the protective silk cocoon.
Presence of imaginal buds viz., a pair of compound eyes, a pair of antennae, two pairs of wings & three pairs of thoracic legs.
It is compact and slightly curved, matching the shape of the cocoon, resembling a small, rounded capsule.
Ventrally 8 segments & dorsally 9 segments are visible.
Presence of 7 pairs of spiracles on ventro-lateral side of abdomen.
It is made of a continuous silk thread offers protection during this vulnerable phase.
Sexual Dimorphism: Male pupae are smaller and less plump compared to female pupae, which are larger and bulkier. A vertical line across the centre of ventral side of 8th segment is visible which is completely absent in females.
- Body is creamy white or pale buff, covered with fine, soft hair-like scales giving a fluffy appearance.
Length 25 mm with a wingspan of 40 to 50 mm.
Body is divided into three regions: head, thorax, and abdomen. The robust, thick, and bristly body is larger in females than males.
Two pairs of cream-colored wings with faint or thin brown lines and dark veins are present. The forewings overlap the hindwings when at rest.
The head has a pair of large compound eyes and a pair of bipectinate antennae. Males have bushy or feathery antennae, while females have smaller, less feathery antennae.
Adults have reduced or absence of mouthparts and do not feed during their brief adult life.
Three pairs of six-segmented legs are present on the thorax.
Tibia has one spur(in female)two spurs (in male)
In male abdomen consists of eight segments and a pair of hook-like structures called Harpes on the caudal end; females have seven abdominal segments and a knob-like projection with sensory hairs.
Six pairs of spiracles are present in the abdomen.
Hence, the specimen seems to be a adult stage of Bombyx mori.
🟢For diagrams: 👉 https://drive.google.com/file/d/1c8JERpKbQ0MIQiiy0P5J_-iyn3089LPJ/view?usp=sharing
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