Laboratory Report on Sericulture Farm Visit in Arbaminch
1. Morphology of Silkworm Life Stages
During the visit to the sericulture farm in Arbaminch, we observed the morphology of various life stages of the silkworm (Bombyx mori):
Egg
- Shape: Ovoid to elliptical, measuring approximately 0.5-0.6 mm in length.
- Color: Initially pale greenish-white, later turning darker as they mature.
- Surface Texture: Smooth, with a delicate membrane.
- Hatching Duration: Approximately 10-14 days depending on environmental conditions.
Larva
- Instars: The silkworm undergoes five instars, each characterized by distinct morphological changes.
- Color: Initially light green, later developing into a creamy white or yellow.
- Size: Grows from about 1 mm at hatching to approximately 80 mm at the end of the fifth instar.
- Body Segmentation: Notable segmentation with a soft, fleshy texture.
Pupa
- Shape: Capsule-like structure, approximately 25-30 mm in length.
- Color: Cocoon varies from white to golden-yellow depending on the silk variety.
- Surface Texture: Smooth exterior, indicative of the silk produced during the larval stage.
Adult
- Appearance: Moths with two pairs of wings; females larger than males.
- Sexual Dimorphism: Males are smaller with slender bodies; females are bulkier.
- Wingspan: Approximately 25-30 mm.
- Coloration: Generally creamy white or light yellow, with darker patterns in some phenotypes.
2. Sex Identification
Sex identification in silkworms can be observed as follows:
- Males: Smaller, with slender elongated bodies and more pronounced genitalia. Examined by gently pressing the abdomen, which exhibits a pointed tip.
- Females: Larger, rounder abdomen with a wider base. The genital opening is more prominent.
3. Disinfection
Types of Disinfection
- Physical Methods: Heat treatment, ultraviolet radiation.
- Chemical Methods: Use of disinfectants such as formalin, bleaching powder, and sodium hypochlorite.
Dosages
- Formalin: 0.1% solution for equipment and surfaces.
- Bleaching Powder: 1:10 ratio with water for thorough cleaning.
- Sodium Hypochlorite: 0.5% for surface disinfection.
4. Rearing Techniques
The following rearing techniques were utilized at the farm:
- Housing: Adequately ventilated and insulated sericulture houses.
- Temperature & Humidity Control: Maintenance of optimal temperature (25-28°C) and humidity (70-80%).
- Feeding: Regular feeding with fresh mulberry leaves, provided in adequate amounts to prevent wastage.
- Health Monitoring: Regular checks for diseases and parasites, implementing biosecurity measures.
5. Biology of Mulberry Plant
- Species: Primary species used is Morus alba (white mulberry).
- Growth: Mulberry plants are fast-growing, requiring well-drained soil and full sunlight.
- Nutritional Value: High in protein, carbohydrates, and minerals; essential for silkworm growth.
- Harvesting: Leaves harvested every 7-10 days for optimal nutrition.
6. Raising of Nursery
Nursery raising involved:
- Seed Selection: Quality silkworm eggs sourced from approved suppliers.
- Incubation: Eggs were incubated in disinfected trays under controlled conditions (temperature and humidity).
- Hatching Management: Regular monitoring to ensure proper environmental conditions for maximum hatch rate.
7. Estimation
Hatching and Brushing Percentage
- Hatching Percentage: Approximately 85% observed.
- Brushing Percentage: 90% of larvae actively feeding.
Moisture Content of Mulberry Plants
-Optimal Moisture Content: Maintained at 70%, determined by scientific methods.
Silkworm Larval Density
- Density: 500 larvae per kg of mulberry leaves.
Cocoon Shell Ratio
- Cocoon Shell Ratio: Average observed ratio was 10-12% of the total cocoon weight.
8. Evaluation of Different Types of Mountages
Several mountages were evaluated for their effects on defective cocoons. Types included:
- Bamboo Sticks: Most efficient with minimal defects.
- Aluminum Frames: High incidence of defective cocoons due to improper support.
- Cardboard Mounts: Intermediate results; used to balance costs and effectiveness.
Effects on Defective Cocoons
- Bamboo mounts correlated to lower rates of defects (less than 5%).
- Aluminum frames resulted in over 20% defective cocoon rates.
- Cardboard mounts demonstrated an 11% defect rate, suitable for cost-effective operations.
Conclusion
The visit to the sericulture farm in Arbaminch provided comprehensive insights into the various aspects of silk production, from the biological aspects of the silkworm and mulberry plant to effective management practices crucial for a successful giriculture venture. The experiences gained will be pivotal in enhancing knowledge and practices in local sericulture initiatives.