How to breed silkworms

Silkworm farming is favored due to its low cost, easy management, short growth cycle, wide market demand and significant economic benefits. Mastering the correct breeding techniques can effectively reduce the difficulties and losses in the breeding process, thereby increasing the economic returns of silkworm breeding. Let’s learn how to raise silkworms.

1. Silkworm egg hatching and silkworm collection

Silkworm egg hatching: From the day the silkworm eggs are shipped out of the warehouse to the fourth day, the temperature should be maintained at 24°C, with a humidity difference of 2.5°C; from the fifth day to the hatching period, the temperature should be adjusted to 26-28°C, with a humidity difference of 1-1.5°C. On the eighth day, when 20% of the silkworm eggs have green spots (a small black spot on one end), they should be shielded from light to promote hatching. At 5 a.m. on the tenth day, remove the shade and turn on the lights to allow the larvae to hatch.

Collection of silkworms: The best time to collect silkworms is 9 am. Use the second mulberry leaf under the terminal bud as food for the silkworms. Cut it into shreds or small cubes and sprinkle it directly on the silkworm seed paper. After letting the larvae crawl onto the mulberry leaves for 10 minutes, turn the larvae and the leaves over onto the silkworm bed and tidy them up.

2. Raising young silkworms

Temperature and humidity: Young silkworms need a high temperature and humid environment to ensure normal development. The temperature of 1-year-old silkworms should be controlled at 28℃, with a humidity difference of 1℃; the temperature of 2-3-year-old silkworms should be 26-27℃, with a humidity difference of 1-1.5℃. To maintain these conditions, 1-2 year old silkworms need to be covered with a lid and have a mat underneath, while 3 year old silkworms only need to be covered with a lid without a mat. If the temperature and humidity are not up to standard, they should be heated and humidified, and the light should be kept distinct during the day and at night.

Feed selection: The mulberry leaves for young silkworms should be strictly selected. The third leaf below the terminal bud (yellow with green) is used for one-year-old silkworms; the 5th to 6th leaf or the second-eye leaf (dark green and shiny) is used for two-year-old silkworms. After mulberry leaves are picked, they should be covered with plastic film and stored in a place with low temperature and slightly higher humidity to keep them fresh.

Feeding frequency: The young silkworms should be kept under plastic film to prevent dryness and fed 3-4 times a day and night. Before each feeding, the seats should be expanded and evenly spaced to ensure that each silkworm has room for two to move around. The feeding amount should be adjusted according to the age of the silkworms. One-year-old silkworms should be fed 1.5-2 layers of leaves each time, two-year-old silkworms should be fed 2-2.5 layers, and three-year-old silkworms should be fed 2.5-3 layers.

Management of young silkworms during sleep:

Sleeping and waking characteristics: The body color of the first-instar silkworm changes from blue-gray to fried beige, the body is slightly shrunk, the body surface is shiny, and the body is sticky with silkworm feces; the body color of the second-instar silkworm changes from blue to milky white, the silkworm has a hunchback phenomenon, and the skin is shiny; the body color of the third-instar silkworm changes from blue-gray to milky white, the body is fat and short, and the body skin is tight and shiny.

Before the silkworms sleep, remove the feces and residues with a net to keep the silkworm beds clean and prevent the spread of silkworm diseases.

Sleep after eating: The silkworms should be fed 1-2 times after removing the sand before sleeping, so that they can sleep quietly after eating.

Raise the silkworms in batches: When more than 95% of the silkworms have fallen asleep, and there are still a few that have not fallen asleep, sprinkle lime powder, add a net and feed them again to lure out the late-sleeping silkworms and raise them separately. After 4-6 hours, these silkworms will fall asleep.

Protection during sleep: First, remove the film and sprinkle fresh lime powder, then lower the temperature in the silkworm room by 1°C and the humidity difference by 1.5-2°C, and avoid strong wind, direct sunlight and vibration.

Feed processing technology:

Feeding time: When more than 98% of the silkworms have shed their skins, their heads have changed from blue-gray to light brown, and they have started to look for food, they can be fed.

Mulberry leaves to be used as food and the amount to be given: The leaves of mulberry leaves should be slightly tender, and the amount of leaves given should be enough to make the silkworms 80% full.

Disinfection of silkworm bodies: Use "Disease Prevention No. 1" to disinfect silkworm bodies and silkworm seats before feeding. Let the silkworms crawl for about 10 minutes, then add the net to the leaves, and remove the sand after 30 minutes.

3. Raising silkworms

Ventilation and humidity: Good ventilation should be maintained during the silkworm period, and doors and windows should be opened to prevent excessive humidity and high temperature.

Hygiene management: Use fresh lime powder to disinfect silkworm bodies and silkworm seats every morning, remove sand every day, and sprinkle lime powder twice a day when the humidity is high on rainy days to keep it dry. Be careful to pick out sick and dead silkworms and eliminate weak silkworms to prevent the spread of silkworm diseases.

The 4th instar is the critical period for the growth of silkworm body to silk gland. Insufficient nutrition will affect the yield and quality. You should choose fresh and good quality mulberry leaves, and pick the 7th to 15th leaves below the top leaves for feeding.

Reasonable use of mulberry trees at the 5th age: The use of mulberry trees at the 5th age accounts for about 85% of the use of mulberry trees at all ages. Reasonable use of mulberry trees is the key to improving efficiency. The specific operation is to tighten the two ends and loosen the middle, that is, the amount of leaves given on the 1st-2nd day and the 6th-7th day of the 5th instar must be strictly controlled, and the silkworms should be fully fed on the 3rd-6th day.

Add chloramphenicol: Add 500 units of chloramphenicol at the start of each age, on the 3rd day of the 4th age, and on the 3rd and 5th days of the 5th age to prevent silkworm diseases.

Spray silkworm fly killing emulsion: spray silkworm fly killing emulsion once on the 2nd day of the 4th instar and the 2nd, 4th and 6th days of the 5th instar, with a concentration of 300 times or 500 times, to prevent fly maggot disease.

4. Cocooning and Cocoon Harvesting

The upper clustering process is to place the mature silkworms on the clustering tool and let them spin silk and make cocoons. Characteristics of mature silkworms include reducing or stopping eating mulberry leaves, excreting large amounts of soft green feces, having a transparent thorax, a slightly soft and shortened body, and raising and swinging the head and thorax from side to side in search of a place to make a cocoon.

Cluster tools: There are various types of cluster tools, bamboo flower clusters, square clusters and plastic folding clusters are commonly used.

Cluster density: 700-800 mature silkworms per square meter on bamboo flower clusters, 156 on square clusters, and 200 on each plastic folding cluster.

Cluster Management:

After the clusters are filled with mature silkworms, arrange the clusters in a "human" shape or hang them in a grid. Pick up the wandering silkworms and rotate their positions every 4 hours.

The temperature in the upper cluster room should be controlled at around 24°C, not exceeding 28°C or below 20°C, with a dry-wet difference of 3-4°C. Strengthen ventilation and dehumidification, and sprinkle moisture-absorbing materials on the ground. The light should be slightly dim and even, and avoid strong winds.

Two days after the cocoons are laid, sick and dead silkworms are picked out to prevent contamination of good cocoons.

Cocoon picking:

The best time to collect cocoons is when the silkworms have pupated and the pupae have turned brown. The suitable period is 5-7 days after spring silkworms have been bred, and 4-6 days after summer and autumn silkworms have been bred.

Before picking cocoons, you should pick out dead silkworms and rotten cocoons first, and then pick good cocoons. The collected cocoons should be placed according to five categories: upper cocoons, lower cocoons, double cocoons, lower cocoons (with yellow spots, purple marks, deformities, etc.), and lower rotten cocoons. The harvested cocoons are spread out on the silkworm tray in a thickness of 2-3 grains.

The above is how to raise silkworms. Silkworm breeding can be regarded as a new industry nowadays, but it is not recommended that you invest blindly. It is more important to learn management techniques and find good sales channels.