CATDOLL : CATDOLL: When does silkworm rearing end?

1. When is the autumn silkworm breeding time in Northeast China?

Spring silkworm breeding begins around April 20th every spring, with a growth cycle of 26-27 days. Summer silkworm breeding begins around May 20th, and after the mulberry trees grow new leaves again, late autumn silkworm breeding begins around June 25th, with a growth cycle of 24-25 days. As the interval between Mid-Autumn silkworms and late autumn silkworms is short, and poor disinfection may affect their growth and quality, Mid-Autumn silkworms are generally not raised. Late autumn silkworms are generally bred starting around September 5th and ending in early October.

2. Why do silkworms die in summer?

If it is a silkworm, then it will die before summer. Because spring silkworms will not stop spinning silk until they die. You can imagine that spring silkworms start spinning silk and making cocoons after April in spring... Once the cocoons are made, it basically declares the end of life, because most of them are directly soaked in hot water to spin silk and peel cocoons, and the silkworm pupae inside are also scalded to death. At this time, it is only the end of spring.

Even after more than 20 days of cocooning, as soon as summer arrives, the silkworm pupae turn into moths, break out of the cocoons, mate and lay eggs immediately, and then die immediately.

3. How long does it take for a third-instar silkworm to become a fourth-instar silkworm?

Usually 3-4 days

First instar silkworm: Brown in color, very small, with a reddish-black head, body length of about 2mm, body width of about 0.5mm, after eating, the body color gradually becomes lighter, and at the end of the instar, the body length reaches 4-5mm. 2. Second instar silkworm: The head is reddish-black, the dorsal thorax is white, and the dorsal abdomen is gray. At the end of the second instar, the body length is about 1cm. 3. Third instar silkworm: The head is no longer black, but gray. At the end of the third instar, the body length is about 1.5-2cm.

4. What is the season for ant silkworms to hatch?

Silkworm eggs usually hatch into young silkworms in spring (late March to around May). Their life cycle is as follows:

1. Silkworm eggs: About 1mm wide and 0.5mm thick. They are light yellow or yellow when just laid. After 1-2 days, they turn into light red bean color or red bean color. After 3-4 days, they turn into gray-green or purple. There is no subsequent change until the larvae hatch, when they turn into white or light yellow.

2. Silkworm: There are 5 instars in total, and they undergo 4 molts. The first instar lasts 4-5 days, the second instar lasts 3-4 days, the third instar lasts 4-5 days, the fourth instar lasts 4-5 days, and the fifth instar lasts 6-8 days. The newly hatched ant silkworm is about 2mm long and 0.5mm wide, and by the fifth instar, the body length of the silkworm can reach 6-7cm.

3. Silkworm pupa: At the end of the fifth instar, the silkworm gradually matures and begins to spin cocoons and become pupae. The silkworm pupa is spindle-shaped, with three body segments: head, thorax, and abdomen. The head has compound eyes and antennae, the thorax has thoracic legs and wings, and the abdomen has 9 body segments.

5. Complete set of techniques for mulberry planting and silkworm breeding?

my country is the origin of mulberry planting and silkworm breeding in the world, with a history of 5,000 years. The silk industry is the industry with the most innovative advantages in my country, and it is a traditional industry that can monopolize and occupy the international market. Moreover, with the improvement of people's living standards, people pay more and more attention to "natural" and "maintenance". Among them, silk clothing with the characteristics of "heat absorption" and "beauty" has been recognized by people, which has led to a continuous increase in the consumption level of silk products. Therefore, it is of great significance to strengthen the research on mulberry planting and silkworm breeding technology.

1. Key points of mulberry technology

1.1 The growing environment of mulberry trees

1.1.1 Temperature. Mulberry trees can only grow healthily in a suitable environment. Usually, when the temperature is above 5℃, the mulberry roots begin to breathe. When the temperature is above 12℃ and there is sufficient water, winter buds can germinate; when the temperature rises to 25-30℃, branches and buds slowly grow out.

1.1.2 Light. Mulberry trees are sunlight-loving species. Sufficient sunlight is needed to ensure smooth photosynthesis and lay the foundation for their healthy growth.

1.1.3 Water. The water content of the whole mulberry tree is about 60%. Insufficient water will affect the growth of mulberry roots and new shoots, causing the leaves to droop and, in severe cases, dead leaves to fall. In the case of excessive water, the soil has poor permeability and lacks oxygen, resulting in poor leaf growth. Long-term flooding will cause the mulberry tree to die, and the mulberry leaves grown cannot be used for silkworm breeding.

1.1.4 Air. Air is an important factor for the growth of mulberry trees. Mulberry trees need to absorb oxygen at night and carbon dioxide during the day for photosynthesis to produce nutrients.

1.1.5 Nutrients. Mulberry trees need a variety of nutrients to grow. For example, phosphorus can guide cell division, promote the growth of rhizomes and the formation of chlorophyll, and enhance the tree's resistance to stress; potassium can transport nutrients, enrich the roots, and accelerate maturity; nitrogen is an important component of mulberry leaf protein synthesis. In addition to the above three substances, trace elements such as iron, copper and manganese are also needed.

1.1.6 Soil. Soil is the foundation for the growth of mulberry trees. The growth of mulberry trees is closely related to soil structure, pH, water and nutrients. Mulberry trees have high adaptability and can grow in soils with a pH value of 4.5 to 9.0, that is, slightly acidic or slightly alkaline. Mulberry trees can be planted in sandy soil and red soil, but the best planting effect is in neutral sandy soil.

1.2 Mulberry seedling planting

1.2.1 Planting period. The first is spring sowing, which is around the Qingming Festival, that is, late March to early April, and no later than the end of April, because it will be affected by rain and high temperature. Rain will wash away the newly planted mulberry seedlings, and high temperature will affect the growth of tender seedlings. The second is autumn sowing, which is around the autumnal equinox, that is, late September. If there is a drought problem during this period, fertilizer and water management should be strengthened. Spring sowing has the best effect.

1.2.2 Planting methods. The first method is scattering, using about 1.00 kg of mulberry seeds for 667 m2; the second method is row sowing, using about 0.65 kg of mulberry seeds for 667 m2, the furrow depth and width can reach 1 cm×1 cm, and the furrow spacing is 17-20 cm. To ensure a more balanced sowing, four or five times the amount of fine sand or fine soil can be mixed in, and a thin layer of plant ash can be spread after sowing, and then the grass nodes are covered and sprayed with water. After two leaves appear, the grass nodes are uncovered, and a sunshade net can also be used for protection.

1.2.3 Planting mulberry trees. First, prepare mulberry seedlings. The best time to plant mulberry seedlings is during the dormant stage of mulberry trees in winter. If you buy seedlings, you should buy those without any problems, especially pay attention to bacterial wilt, and the seedlings should not be affected by wind and light. Secondly, usually 5,000 to 7,000 hybrid mulberry trees are planted per 667 m2, with single row and wide and narrow row planting. Single row planting is more conducive to weeding and fertilization; it is better to choose east-west direction to facilitate photosynthesis. The specifications of single row planting are 0.60 to 0.67 m in row spacing and 0.10 to 0.13 m in plant spacing.

2 Key points of silkworm rearing technology

2.1 Disinfection and disease prevention

In order to prevent the occurrence of silkworm diseases, effective disinfection is required during the breeding process, which is an important measure to improve the quantity and quality of silkworms. Disinfection is usually carried out 7 days before silkworm breeding. Before disinfection, the silkworm room, leaf room and surrounding environment should be cleaned first. When disinfecting the silkworm room, 500 g of NaClO stock solution can be dissolved in 12 kg of clean water to prepare 0.4% NaClO disinfectant for disinfection. In the process of disinfecting the silkworm room or tableware, make sure to spray it wet and thoroughly, or directly soak the items to be disinfected in the solution to achieve the purpose of disinfection.

In addition, workers should wash their hands and change shoes frequently, that is, wash their hands before entering the silkworm room, before picking leaves or feeding silkworms, and after removing silkworm feces. Whether entering the silkworm room or the leaf room, they should change their shoes in time to prevent viruses or substances that are not conducive to the growth of silkworms from entering under the soles of their shoes.

2.2 Feeding and management

In the process of silkworm rearing, feeding is very important, which can improve the efficiency and quality of actual rearing work. During the feeding process, on the one hand, the silkworm seats should be kept even, ensuring that each silkworm can occupy about 2 spaces. When feeding silkworms, it is necessary to adhere to the principle of multiple feedings and reasonable control of the number. On the other hand, the freshness of mulberry leaves should be ensured to ensure the healthy growth of silkworms.

2.3 Feeding techniques

When raising young silkworms, you need to choose a special small silkworm room; when raising adult silkworms (strong silkworms), remember the following 20-word mantra, "Young silkworms are raised in nylon, adult silkworms are raised in ground resistance, thoroughly prevent fire poison, and feed them well to prevent heatstroke."

Specifically, first, expand and evenly distribute the silkworm seats, carry out reasonable sleeping and waking treatment, scientifically divide the batches, and feed appropriately; second, adjust the size of the mulberry trees appropriately, and balance the feeding of mulberry trees. Pay attention to the silkworms and the feeding of mulberry trees, and do a good job of replenishment; third, remove sand in time to ensure that the silkworm seats are clean and pollution-free. Adult silkworms need to do a good job of ventilation and dehumidification, and strengthen the disinfection of silkworm bodies and silkworm seats; fourth, carry out effective mulberry leaf collection and transportation to ensure the appropriate age and heat, and optimize the preservation of mulberry leaves; fifth, disinfection and disease prevention work cannot be relaxed, ensure overall disinfection before silkworm rearing, disinfection at any time during silkworm rearing, and disinfection immediately after silkworm rearing. In order to prevent the invasion of diseases, wash hands before feeding, and change shoes before entering the silkworm rearing room; sixth, put the silkworms in the cocoon appropriately to prevent the situation of being too unfamiliar and too dense. The density of the cocoon should be appropriate, with 600 to 700 heads in a flower cluster and about 300 heads in a plastic folding cluster; seventh, do a good job of cluster protection and silkworm rearing. After being put on the cocoon, the silk-spinning process usually ends in two or three days, and then the silkworms molt for about 2 days. The silkworms need to excrete 50% of the water in their bodies, so the room temperature should be very high, and ventilation and dehumidification should be done well. The location where the silkworms are put on the cocoon should meet the requirements of "three dryness".

At the same time, appropriate silkworm collection can prevent premature behavior from damaging the pupae or hair feet. If the silkworms are too late, they will appear moths or maggots. Usually, they can be studied by skinning the silkworms. If they are found to have pupated and the pupal skin turns yellow, they can be collected. When collecting silkworms, thin skin, internal and external dyeing should be separated. The collected silkworms cannot be piled up to heat up, so as not to affect the quality of the silkworms.

2.4 Silkworm disease prevention and control

2.4.1 Classification of silkworm diseases. The first is infectious silkworm diseases. Usually, they are manifested in the form of microparticle diseases, viral diseases, and fungal diseases. In my country's rural silkworm breeding work, infectious silkworm diseases generally have the greatest impact. For example, if there is a serious pus disease, the silkworms will not be able to cocoon, which will have a great impact on the development of agricultural economy. The second is non-infectious silkworm diseases. This non-infectious silkworm disease is mostly caused by parasites, or physiological diseases caused by poisoning, punctures, etc.

2.4.2 Prevention and treatment measures. Because there are many types of silkworm diseases, prevention and treatment should be carried out according to local conditions. The cure of silkworm diseases is often not obvious, so prevention should be the main focus during silkworm rearing. First, strengthen disinfection efforts to prevent the emergence of pathogens and comprehensively hinder the spread of silkworm diseases. Strengthen the management of silkworm rooms, improve the resistance of silkworms, and effectively protect the safety of silkworms. Secondly, once suspected diseases and insect pests are found, timely judgment and identification should be made, and the causes of the problems should be studied to comprehensively prevent the impact of diseases and insects and provide protection for the growth of other healthy silkworms.

3 Conclusion

As people's living standards continue to improve, high-end silk clothing has become something that ordinary people can buy. At the same time, as manufacturers continue to innovate products and expand their own development paths, the needs of consumers from all walks of life can be met, thereby increasing the sales volume of the silk market. Therefore, strengthening the research on the key points of mulberry planting and silkworm breeding technology can effectively increase farmers' economic income.

6. How many days does it take for silkworms to spin silk and make cocoons?

It takes about 10 hours to 2 days for silkworms to spin silk and make cocoons.

The larval stage of a silkworm lasts about twenty-five days, the first instar lasts four to five days, the second instar lasts about three to four days, the third instar lasts about four days, the fourth instar lasts about six days, the fifth instar lasts about seven to nine days, the pupal stage lasts fourteen to eighteen days, and the moth stage lasts three to five days. After the silkworms emerge from their pupae, they will no longer eat, and their wings will only harden after an hour.