MULBERRY SILKWORM MOTH
Mulberry silkworm races

Silkworm breed is the most influential factor in the development of sericulture. In the long history of sericulture, many silkworm races have been recognized as valuable for practical use and the same have been preserved.
Bombyx mori silkworms are classified into Japanese, Chinese, European, Korean and Tropical races.  Japanese (dumbbell cocoon shape) and Chinese race (oval cocoon Shape) are mainly used in the temperate zone. In the tropical zone polyvoltine races are used or as one of the parents crossing with Japanese or Chinese race.

Distinct features based on voltinism

Univoltine: Suitable for cooler places, growth period of larvae is longer having big body. Cocoon and silk quality is excellent. High temperature and high humidity are not suitable. The univoltine silkworm, ‘Borapolu’ or ‘Barpat’ endemic to Assam
Bivoltine: Suitable for warmer places. Larval duration shorter compared to univoltines. Larva is robust, cocoon and silk quality is good. Moderately suitable to high temperature and high humidity.
Polyvoltine: Adaptable to warmer places, larval duration is shorter, larva is robust, small cocoon, silk quality is poor. Lays only non-hibernated eggs. ‘Chotopolu’ or ‘Sarupat’ and ‘Moria’ are endemic to this region.

NEW PRODUCTIVE BREEDS/HYBRIDS
CSR2: A new bivoltine breed evolved from the Japanese commercial hybrid at CSRTI, Mysore
EGG: Newly laid eggs are yellow in colour. The egg number ranging from 450-500
LARVA: Newly hatched larvae are deep brown in colour.  Matured larvae bluish white in colour. Larval duration 23-24 days (in controlled condition) . fifth age larval duration 6-7 days.
COCOON: white, oval in shape with fine to medium grains with scanty floss. Survival 85-90%, cocoon weight 1.80-1.95g, cocoon shell weight 0.45-0.5g, cocoon shell ratio 24-26%, Raw silk % 20-22%, filament length 1000-1300mts, neatness 85-90 (points).
MOTH: Spinning to moth emergence period is about 13 days. Lays hibernating eggs. No. of eggs per grem 1880
CSR4:  A new bivoltine breed evolved from the Japanese commercial hybrid at CSRTI, Mysore
EGG: Newly laid eggs are bright yellow in colour. The egg number ranging from 600-650
LARVA: Newly hatched larvae are blakish in colour.  Matured larvae reddish tinge in colour. Larval duration 24-25 days (in controlled condition) . Fifth age larval duration 6-7 days.
COCOON: white, elongated dumbbell with round end,  fine to medium grains with scanty floss. Survival 90-95%, cocoon weight 1.90-2.15g, cocoon shell weight 0.45-0.5g, cocoon shell ratio 21-22%, Raw silk % 16-17%, filament length 1000-1200mts, neatness 85-90 (points).
MOTH: Spinning to moth emergence period is about 14 days. Lays hibernating eggs. No. of eggs per grem 1810
CSR5:  A new bivoltine breed evolved from the Japanese commercial hybrid at CSRTI, Mysore
EGG: Newly laid eggs are bright yellow in colour. The egg number ranging from 475-525
LRVA: Newly hatched larvae are blakish in colour.  Matured larvae bluish with reddish tinge.  Larval duration 24-25 days (in controlled condition) . Fifth age larval duration 6-7 days.
COCOON: white, elongated dumbbell with round end, mild constriction, fine to medium grains with scanty floss. Survival 85-90%, cocoon weight 1.80-1.05g, cocoon shell weight 0.45-0.5g, cocoon shell ratio 24-25%, Raw silk % 20-21%, filament length 1000-1200mts, neatness 85-90 (points).
MOTH: spinning to moth emergence period is about 14 days. Lays hibernating eggs. No. of eggs per grem 1780
NEW PRODUCTIVE BIVOLTINE HYBRIDS
Characteristics of new hybrids CSR2 x CSR4 and CSR2 x CSR5
CSR2 x CSR4 and CSR2 x CSR5 are characterized by its roboutness, high shell ratio, better neatness and reelability. Favourable rearing season September to February in south India and during in temperate/ sub tropical zones. Moulting is uniform, larval period 23 days.

Fecundity: 590
Hatching percentage: 96.2
Larval duration:23 days, Hours: 0.00
Yield /10,000/Nos. :9595
Yield/10,000 larvae/ wt./Kg :21.67
Single cocoon weight(g): 2.26
Single shell weight (g):0.553
Shell ratio percentage:24.5
Filament length(m):1285
Raw silk percentage:19.5
Denier :2.95
Reelability % :88.0
Renditta:4.9