CATDOLL : CATDOLL: Seeking silkworm breeding technology and silkworm species

Sericulture technical knowledge

1. Preparation before silkworm rearing

1. Sericulture production layout

The layout of silkworm production refers to how many batches of silkworms are raised in a year, when each batch of silkworms is raised, and the number of silkworms raised in each batch. It is not only a management issue, but also a complex technical issue. The rationality of the silkworm production layout not only directly affects the yield and quality of silk cocoons, but also affects the growth of mulberry trees and the utilization rate of silkworm tools in the silkworm room, and ultimately affects the economic benefits of silkworm business.

When making the layout of sericulture production, we must base it on the local climate characteristics, mulberry tree growth conditions, sericulture equipment conditions, sericulture labor resources, sericulture technology level and local crop farming systems, and take all aspects into consideration.

There are three main types of silkworm production layout:

① The layout of silkworm rearing during the first stage with the main purpose of improving the quality of cocoons is not only the purpose of silkworm production, but also an urgent need for silk processing industry and foreign trade export. To improve the quality of silkworm cocoons and the economic benefits of silkworm management, the number of silkworms raised in the silkworm period with poor cocoon quality and low benefits should be reduced as much as possible or their feeding period should be adjusted, and the number of silkworms raised in the silkworm period with good cocoon quality and high economic benefits should be increased as much as possible.

4. Sericulture

② The layout of silkworm rearing in stages is mainly based on the quality and yield of mulberry leaves. The silkworm rearing time is arranged during the period when the mulberry leaves have the best quality, so that the silkworm cocoon production can easily achieve the goal of high quality and high yield. The mulberry tree sprouts and grows from early spring to fall leaves and dormant in winter, which is a long time span. The age and maturity of mulberry leaves vary greatly at different harvesting periods and different leaf positions. Raising silkworms in stages throughout the year is in line with the growth characteristics of mulberry trees and is conducive to increasing the production of mulberry leaves; it can achieve timely selection of leaves of appropriate maturity; it can also ease the tense state of silkworm tools in the silkworm room, make full use of silkworm tools and silkworm rearing labor resources, so that the silkworms are sparsely placed and the good mulberry leaves are well fed, creating conditions for high-quality and high-yield cocoons.

② The layout of silkworm breeding is mainly aimed at adapting to local climate conditions, farming systems and market demand. Because there are great differences in the proportion of sericulture production, farming systems, climate conditions, etc. in different regions. The layout of silkworm breeding production must take into account local climate conditions, farming systems and other factors. For example, in the Huzhou silkworm area of ​​Zhejiang Province, due to the relatively developed local township industry, the early autumn silkworms and late autumn silkworms have low production, low cocoon production, poor cocoon quality and unstable silkworm production. In order to improve the utilization rate of silkworm breeding labor and adapt to the social and economic development of the region, the three autumn silkworms of early autumn silkworms, mid-autumn silkworms and late autumn silkworms were changed to two autumn silkworms of early mid-autumn silkworms and late mid-autumn silkworms, thereby improving the quality of silk cocoons and improving the economic benefits of silkworm production.

my country has a vast territory, and the layout of sericulture production in various sericulture areas is very different. In the Yangtze River Basin, sericulture is carried out 4 to 5 times a year from late April to mid-to-late October. In the Pearl River Basin, sericulture is carried out 7 to 8 times a year from March to November. In North China, sericulture is carried out 2 to 3 times a year from May to September.

(1) Spring silkworms The spring silkworm season has a suitable climate, high-quality mulberry leaves, and few pathogens, making it the best time of the year for silkworm rearing. Therefore, it is important to raise as many silkworms as possible, so that they are fully fed with leaves. Generally, 650-700 kg of leaves are used per silkworm seed, and the number of silkworm seeds that can be raised is estimated.

(2) Summer silkworms Summer silkworms are mainly raised on the sparse buds and leaves after the summer felling of mulberry trees. They can also be raised on some of the mulberry leaves cut in spring or the remaining leaves from the spring silkworm period. After the summer felling of mulberry trees, timely thinning out the dense, thin, weak and drooping buds and leaves is conducive to the ventilation of the mulberry trees, concentrating nutrients to promote the healthy growth of buds and branches, and ensuring the yield and quality of autumn leaves and spring leaves of the following year. In other words, it is necessary to properly raise summer silkworms. Summer silkworms are generally arranged from late June to mid-July, and the number of silkworms raised accounts for 25% to 30% of the number of spring silkworms. The leaves collected should not exceed 4 to 5 leaves at the base of the new shoots after summer felling.

(3) Early Autumn Silkworms The early autumn silkworm breeding period is July. From the second half of the month to the second half of August, the climate is hot, dry and changeable, which is the worst breeding period of the year. Early autumn silkworms mainly use mulberry branches and leaves for breeding. Proper leaf picking can promote the continued growth of branches and improve the leaf quality of mid-autumn silkworms. However, excessive leaf picking will inhibit the normal growth of mulberry trees, affecting the breeding of mid-autumn silkworms and the yield of spring leaves in the following year. For this reason, early autumn silkworms should not be raised in large numbers, and the number of silkworms raised is about 40% to 45% of that of spring silkworms.

(4) Mid-Autumn silkworms are the focus of autumn silkworms. The climate at this time is more suitable for the growth and development of silkworms and mulberry trees. Therefore, on the basis of doing a good job in estimating the yield of the mulberry garden, it is necessary to raise enough silkworms to make full use of the mulberry leaves. The breeding amount is generally 85% to 95% of the spring silkworms, and 7 to 8 leaves are left at the tip of the branches after the leaves are harvested.

(5) Late Autumn Silkworms The late autumn silkworm period is from the 10th day of September to the end of October. The feeding amount is determined by the amount of leaves left after the mid-autumn silkworms (i.e., the late autumn silkworms are raised according to the leaves), which is generally 10% to 15% of the spring silkworms. At least 3 to 4 leaves must be left on the branches after the leaves are harvested. Do not shave the branches completely to maintain normal photosynthesis, allow the tree to accumulate enough nutrients to survive the winter, and maintain the tree's vigor.

2. Silkworm room and silkworm tools

(1) Silkworm room The silkworm room is where the silkworms live and where the breeders operate. Its structure should be conducive to the regulation of indoor temperature and humidity and silkworm rearing operations. It should be located away from poison sources and convenient for cleaning, disinfection, and microclimate regulation. At present, sericulture in rural areas is mostly a sideline production. The scale of sericulture in a household is generally small, and farmers use their houses as silkworm rooms. Therefore, when building new houses in silkworm areas, the requirement of using them as silkworm rooms should be considered. According to the purpose and requirements of sericulture production, silkworm rooms can be divided into small silkworm rooms, large silkworm rooms, mulberry storage rooms, and upper cluster rooms.

① Small silkworm room refers to the silkworm room used to raise silkworms aged 1 to 3. Since young silkworms need a high temperature and high humidity environment, the small silkworm room is required to have good heat preservation and moisture retention properties. In sericulture, farmers with good conditions build special silkworm rooms for young silkworms, while farmers with unsuitable conditions use plastic film to enclose a small room from the original house as a small silkworm room. The heating facilities of the small silkworm room should be selected according to the characteristics of the house. At present, the simple heating facilities that are more suitable for breeding in rural households are as follows:

Ground fire dragon: A rotary flue is built on the floor of the silkworm room with bricks to dissipate heat and heat the silkworm room. It is easy to build and can be removed when not in use without damaging the floor, but it takes up space and affects silkworm breeding operations.

5. Sericulture

Ground Fire Dragon: A rotary flue is built under the floor of the silkworm room, and a thin layer of yellow sand is laid on the flue to dissipate heat and heat the silkworm room. It has the advantages of good heating and humidification performance, small space, and easy operation, but the original floor must be damaged during construction.

Sky Fire Dragon: Use iron pipe as flue, rotate and hang in the air of silkworm room to heat. It is convenient to install, but it takes up space in silkworm room, affects feeding operation, and its heat preservation and moisture retention performance is not as good as ground fire dragon.

② Large silkworm room refers to the silkworm room used to raise silkworms of 4 to 5 years old. Large silkworm room requires good ventilation and air permeability. At present, rural silkworm farmers use large silkworm room as their residence.

③ The mulberry storage room is a place for storing mulberry leaves. It should be low temperature, high humidity, dim light, close to the silkworm room and easy to clean and disinfect. A dedicated mulberry storage room should be a basement or semi-basement, while a combined mulberry storage room should be a small room with a cement floor and no direct light.

④ The cocoiling room is usually used together with the silkworm room, which requires good ventilation and dehumidification performance and uniform lighting.

(2) Silkworm tools All tools needed for silkworm rearing are collectively called silkworm tools. There are many types of silkworm tools. They can be divided into the following categories according to their uses.

① Disinfection equipment: sprayer, bucket (or tank), hose, sterilizer, broom, etc.

② Ant collecting tools include silkworm chopsticks, goose feathers, ant collecting paper (or net), etc.

③ Feeding tools: silkworm plaque, silkworm rack, mulberry feeding rack, silkworm net, plastic film, anti-drying paper, dry-wet thermometer, mulberry cutting knife, mulberry cutting board, scale, sand removal basket, etc.

④ Tools for picking and storing mulberry trees: picking baskets, mulberry shears, mulberry storage jars, air cages, mulberry covering cloths, etc.

⑤ Tools for clustering: clustering tools (square clustering, folded clustering, centipede clustering, etc.), reed curtains, clustering frames, etc.

The production of silkworm tools can be adapted to local conditions, but the material structure must be suitable for the physiological hygiene of silkworms and easy to clean and disinfect; it should be easy to obtain from trees, simple to make, inexpensive and good quality; some can also be used for daily life and production tools; it should be solid and durable, light to use; and easy to carry, store and keep.

3. Preparation of production materials for sericulture

(1) Selection of silkworm varieties Selecting excellent silkworm varieties is an important part of safe silkworm farming and improving the yield and quality of silk cocoons. Different silkworm varieties have different requirements for environmental conditions. Therefore, the selection of silkworm varieties should be based on comprehensive considerations of the climate, leaf quality, feeding conditions and feeding techniques of the local area. The climate is suitable and the leaf quality is good during the spring silkworm season, so spring silkworm varieties with high silk yield should be selected; the climate is harsh in summer and autumn, and the leaf quality is poor, so summer and autumn silkworm varieties with strong physique should be selected; in areas with serious air pollution (fluoride pollution), silkworm varieties with strong fluoride resistance can be selected. Please refer to the previous introduction to silkworm varieties and traits for details.

(2) Preparation of mulberry leaves Before raising silkworms, it is necessary to estimate the yield of mulberry leaves, determine the species based on the leaves, and balance the species. Under the premise of making full use of mulberry leaves without affecting the physiology of mulberry trees, the cocoon yield per mu of mulberry trees can be increased. The yield of mulberry leaves should be estimated based on a comprehensive analysis of factors such as mulberry tree variety, tree age, planting form, fertilizer management, climatic conditions, leaf use time, and leaf production in previous years. There are two main methods for estimating the yield of spring leaves: strip length estimation method and experience estimation method. Strip length estimation method is a method of estimating the yield of mulberry leaves based on the total strip length of the mulberry garden and the leaf production per meter of mulberry branches. It is a commonly used method in production. Shouguang classified mulberry gardens according to the growth, age, and variety of mulberry trees, and then selected 15 to 20 representative mulberry trees from each type of mulberry garden to investigate the total length of mulberry branches per mu, and then estimated the yield of meter-long spring leaves (the yield of meter-long spring leaves is 0.08 to 0.1 kg, which is flexibly controlled according to the mulberry tree variety, age, fertilizer cultivation level, climatic conditions, germination rate, actual situation of the previous spring, etc.), and finally deduced the commercial mulberry leaf yield; the empirical yield estimation method is to determine the spring leaf yield based on the previous year's spring leaf yield combined with fertilizer cultivation management, branch length and thickness, current year's climatic conditions and harvest date. It is generally suitable for silkworm farmers with rich experience in mulberry planting. The estimated yield of summer leaves and autumn leaves is based on the yield of spring leaves and the timing of summer felling, the climate conditions at that time, fertilizer management, and the growth of mulberry trees. The yield of spring leaves is 100%, and the general yield of summer leaves is 15%~20%, the yield of early autumn leaves is 30%~35%, the yield of mid-autumn leaves is 65%~70%, and the yield of late autumn leaves is 15%~20%. The amount of leaves used varies depending on the feeding season, silkworm species, feeding conditions and feeding techniques. For spring silkworms, each silkworm seed generally requires 650~700 kg of leaves (bud leaves, spring); for summer and autumn silkworms, each silkworm seed generally requires 450~550 kg of leaves (leaves, summer and autumn).

(3) Labor arrangement The labor required for sericulture varies according to the breeder's technical level, breeding method, breeding season, etc. For young silkworms, dry-proof rearing and normal rearing, the amount of silkworms that a skilled breeder can afford is generally: 4-5 silkworms for 1-2 year old silkworms, 3 silkworms for 3 year old silkworms, 2-2.5 silkworms for 4 year old silkworms, and 1-1.5 silkworms for 5 year old silkworms. The period from 3 to 5 year old silkworms does not include leaf picking. Other breeding methods and breeders can be appropriately increased or decreased according to the above standards.

(4) Preparation of silkworm rooms, silkworm tools and consumables The required quantity of silkworm rooms, silkworm tools and major consumables should be calculated according to the number of silkworm seeds to be raised and all should be prepared before silkworm rearing.

6. Sericulture

2. Sericulture Technology

Feeding standards

In sericulture, it is customary to call the main technical requirements developed based on different feeding methods as feeding standards or feeding reference tables. For example, the feeding standards for young silkworms in three-times of bed-raising, and the feeding reference table for silkworms in strips of mulberry. The contents of the feeding standards or feeding reference tables generally include age, date, feeding temperature and humidity, feeding time, number of feedings, feeding amount, silkworm bed area, technical treatment points, etc. During the young silkworm stage, the mulberry size should be increased, and during the adult silkworm stage, it should be noted whether buds, leaves, or strips of mulberry should be used.

Standards for mulberry trees of different ages

The moisture content of silkworms in the larval stage is 75%, rising to 85% at the end of the first instar; thereafter, it remains relatively stable between 85% and 88%, and begins to decline in the third silkworm of the fifth instar, and drops to around 75% when the silkworm is mature. The analysis data of the chemical composition of the dry matter of silkworms show that the quality requirements for mulberry leaves given at different instars are different. The combination of the silkworms' requirements for moisture and nutrients constitutes the standards and principles for selecting mulberry leaves for each instar. Young silkworms, especially those in the first and second instars, require mulberry leaves that are soft, tender, and contain more moisture and protein. As the age of the silkworm increases, the carbohydrate content of the mulberry leaves used should be gradually increased, and the moisture and protein content can be gradually reduced. The moisture, protein, and carbohydrate content of mulberry leaves are related to the location of the leaves on the branches, that is, the leaf position. From the tip to the base, the moisture and protein gradually decrease, and the soluble carbohydrates increase accordingly. Therefore, the selection standards for mulberry trees at different ages are generally as follows, taking lake mulberry trees as an example: in the first age, select the 3rd and 4th leaves from the top of the bud tip, and the leaf color will turn dark green; in the second age, select the 5th and 6th leaves, and the leaf color will just turn dark green; from the third age onwards, three-eyed leaves can be picked, and the color is dark green; in the fourth and fifth ages, in addition to paying attention to choosing softer mulberry leaves when feeding, three-eyed leaves, new shoot leaves or strip mulberry leaves can be used for feeding.

Feeding temperature and humidity

Silkworms are cold-blooded animals, and their body temperature is controlled by the ambient temperature. When there is no airflow, the body temperature is slightly higher than the external temperature (no more than 1 degree Celsius), and when there is airflow, the body temperature is slightly lower than the external temperature. It is generally believed that the temperature range suitable for the growth and development of mulberry silkworms is 20-30℃. Within this developmental temperature range, the temperature should be higher during the young silkworm stage and lower during the adult silkworm stage. The most suitable feeding temperature for each age is 27-29℃ for the first age, and then decreases by about 1℃ for each age, to 22-24℃ for the fifth age; during the hibernation of each age, the temperature should be about 1℃ lower than when eating mulberry. Long-term exposure to high temperatures above 30℃ or low temperatures below 20℃ will disrupt the growth and development of silkworms. The relative humidity of feeding should be avoided as much as possible, 80%-85% for the first and second ages, and then reduced by about 5% for each age, and 75% is appropriate for the fifth age. Too wet or too dry will affect the development and health of silkworms.

Feeding method

It is also called feeding method or feeding type. In silkworm production, a feeding method with certain characteristics is usually referred to as "feeding". For example, according to the number of mulberry feeding per day, those less than 4 times are collectively called "few-time feeding", and are further divided into four-time feeding, three-time feeding, two-time feeding and one-time feeding; according to the feeding place, those feeding outside formal buildings are collectively called "outdoor feeding", those using the bottom of the earth pit as the silkworm seat and building a shed to cover it are called "earth kang feeding", and those using the shade of the trees to build feeding sheds are called "forest feeding" or "shade of the trees"; those using silkworm plaques as silkworm seats are called "silkworm plaque feeding", and those that set up silkworm frames and lay reed curtains to fix the silkworm seats so that they cannot move freely are called "silkworm platform feeding"; there are heated kangs on the surface or underground of the silkworm room, Flue, specially used for raising young silkworms is called Kang bed breeding, among which the one with larger area and larger feeding capacity is called Kang room breeding; after feeding mulberry, anti-drying paper is covered to prevent mulberry leaves from withering, and polyethylene plastic thin wax is used to cover it in the 1960s and 1970s, which is called plastic film covering breeding; according to the form of mulberry leaves, the one with leaves is called leaf breeding, the one with full buds is called full bud breeding, and the one with strips of mulberry is called strip mulberry breeding; according to the feed, the one fed with mulberry leaves is called mulberry leaf breeding, and the one fed with artificial feed is called artificial feed breeding. Sometimes several characteristics are combined to set a name, such as: three-time Kang bed breeding for young silkworms, strip mulberry breeding, standing breeding for young silkworms with leaves, artificial feed for young silkworms, etc.

Cocoon breeding

The cocoons used for laying eggs and producing seeds are called seed cocoons, and the silkworm breeding for the purpose of obtaining cocoons for producing seeds is called seed cocoon breeding. In seed cocoon breeding, purebred or original species of both Chinese and Japanese systems are raised at the same time. The seed cocoons obtained by the Chinese system are short ellipsoidal, while those of the Japanese system are waisted.

Silk cocoon breeding

The cocoons used for reeling silk are called silk cocoons, and the silkworm breeding for the purpose of obtaining raw materials for reeling silk is called silk cocoon breeding. The cocoons obtained by raising silk cocoon breeding are generally long oval in shape.

Moth breeding

The eggs laid by a female moth are considered a group, and the unit of measurement is moth or moth zone. Raising silkworms in moth zones is called moth zone rearing, also known as single moth rearing. There are 400-500 silkworms in a moth zone, and about 4-6 silk cocoons can be obtained after rearing. Moth zone rearing is often used in the silkworm variety selection stage; the silkworm seed breeding technology operation regulations stipulate that moth zone rearing must be used to breed the original mother seed and the original seed.

7. Sericulture

Ant breeding

Mix the larvae hatched from several or even dozens of moth areas, and weigh a certain weight of larvae as a breeding unit, which is called mixed larvae breeding or larvae breeding. To breed the original species, use 1 gram of larvae in a fixed moth area; to breed the original species, use 28 moth frames to breed the original species or 4 grams of larvae in the scattered egg original species. The breeding of hybrids is calculated in boxes, and each box has about 10 grams of larvae. 1 gram of larvae contains about 2100-2300 larvae.

Upper cluster

The process of collecting mature silkworms, transferring them to cocoons, and letting them spin silk and make cocoons is called cocooning. There are four methods of cocooning: (1) Manual picking, where the silkworms of appropriate maturity are picked up one by one by hand and then spread on the cocoons. This method is time-consuming and labor-intensive and is generally used for cocoon breeding. Manual picking is also adopted in the early stage of silk cocoon breeding, but when a large number of mature silkworms appear in the most mature stage, most people adopt other methods to cocoon them; (2) Natural cocooning, where the mature silkworms have the tendency to turn their backs to the ground and like to climb upwards. In the most mature stage, the cocoons are placed directly on the silkworm seats, allowing the mature silkworms to automatically climb onto the cocoons to spin silk and make cocoons. This method is highly efficient, but it is easy to produce cocoons in the silkworm beds. At the same time, special attention must be paid to ventilation and dehumidification, otherwise the cocoon quality will be affected; (3) The shaking-off method: when the silkworms are grown in the adult stage, the upper mulberry strips can be removed, the mature silkworms can be shaken off and collected on the cocoon beds; (4) The mesh collection method: when the silkworm beds are mature, a layer of perforated plastic film is covered on the silkworm beds. The mature silkworms that have climbed onto the film through the holes can be collected and put on the cocoon beds by taking advantage of the upward climbing characteristics of the mature silkworms. This method is being gradually promoted in some major silkworm-breeding areas in China.

Suitable period for clustering

The silkworms should be placed on the cocoons when they are mature enough. Placing them on the cocoons too early or too late will have an adverse effect on the cocoon yield and quality. If the immature silkworms are placed on the cocoons or stopped too early, there will be an increase in the number of silkworms that do not form cocoons or die in the cocoons, the cocoon layer will be thin, the silk yield will be small, and the feces of the late-forming silkworms will contaminate the early-forming cocoons due to the different cocooning speeds of the group, resulting in unclean cocoon color; if the over-mature silkworms are placed on the cocoons or stopped too late, part of the silk yield will be wasted, and more cocoons will be formed, such as double palaces, firewood seals, thin skins and irregular shapes.

Clustering density

Refers to the number of mature silkworms placed per unit area or per cocoon. There are 450-500 mature silkworms per square meter in centipede cocoons, and 400-450 per square meter in folded cocoons. Too sparse is not economical, and too dense will affect the cocoon quality and cocoon rate. Each square cocoon sheet has 156 grids (13 vertical holes, 12 horizontal holes, 3×4.5cm grid, 3cm deep). When cocooning, it is appropriate to place mature silkworms at 80%-85% of the number of grids.

Cluster management

Including the environment and protection in the cocoon, whether it is appropriate or not has a great impact on the quality of cocoon growth. Under the premise of appropriate maturity and reasonable density, the key in the cocoon is to manage the temperature, humidity, light and airflow in the cocoon room. The temperature should be around 24℃. If it is too high, the mature silkworms are eager to make cocoons, which is easy to increase and slow to make cocoons, and it is easy to increase thin cocoons and silkworms that do not make cocoons. As the saying goes, two pounds of mature silkworms make one pound of cocoons. The amount of feces and urine discharged by mature silkworms in the cocoon and the amount of water emitted during the spinning process are large, so the temperature naturally rises. Excessive humidity seriously affects the relaxation of cocoons, and will also increase the number of dead silkworms and silkworms that do not make cocoons. Therefore, the relative humidity of the cocoon room should be controlled at about 75%, and there should be a certain amount of airflow in the room. Mature silkworms have a certain tendency to phototropism, but they avoid strong light above 100L. The general requirements for management in cocoons are: the temperature is centered at 24°C, and it should be slightly higher in the early stage of cocooning, and can be appropriately lowered after the cocoon shape is formed; the humidity should be 75°C, and it should not be stuffy or damp; avoid strong winds in the early stage of cocooning, and after the cocoon shape has been initially formed after a day and a night, doors and windows should be opened to increase ventilation, so that there is a wind speed of 0.5-1.0m/s in the room to continuously expel the emitted moisture; the light should be uniform and bright; the environment should be quiet, and all kinds of vibrations should be avoided as much as possible.

Spinning silk and making cocoons

At the end of the fifth instar, the silk gland cavity of mature silkworms is filled with liquid silk material. At this time, the silkworm body's head and chest are raised and wandering on the silkworm seat, swaying left and right to spit out silk threads, looking for a place to build a cocoon. Spinning silk and building a cocoon is an instinctive habit of silkworms. The process of spinning silk and building a cocoon after mature silkworms go on the cocoon can be roughly divided into four periods: the first is to tie the cocoon net, which serves as a support for formal cocooning; the second is to tie the cocoon coat, which gives it a cocoon-shaped outline. The silk fibers of the cocoon net and the cocoon coat are relatively messy and cannot be reeled, but can only be used as raw materials for silk spinning; the third is to tie the cocoon layer, which is the main part that can be used for reeling; and the fourth is to tie the pupa lining. The average spinning speed is 1.1cm/s at 24℃, and it takes about 60-70h from the beginning of going on the cocoon to the end of spinning. The form of the silk arrangement, the outer layer of hybrids is generally S-shaped, and it changes to ∞ shape at the stage of tying the cocoon layer.

Cocoon Harvesting

Picking the cocoons from the cocoon is called picking cocoons. Except for the cocoons on the square cocoon, which can be picked by mechanized or semi-mechanized cocoon pickers, the cocoons on other cocooning tools can only be picked by hand. The silkworms start to spin silk after about 3 days from maturity, and then molt and pupate after 2-3 days. As the age of the newly molted pupae increases, the body color gradually turns to light yellow, yellow, light brown, and jade tea brown, and the body wall gradually hardens. Generally, the time for picking cocoons is when the pupae's body color turns yellow, that is, the 6th to 7th day after being cocooned in the spring silkworm period, the 5th to 6th day after being cocooned in the summer and autumn silkworm period, and the 7th to 10th day after being cocooned in the late autumn silkworm period. The cocoons picked before pupation are commonly known as hairy cocoons, and it is not easy to dry them evenly when drying them; the cocoons picked when they have just pupated are too tender and easy to be injured and bleed, thus contaminating the cocoon layer and causing inner cocoons; the cocoons picked too late will increase the number of maggot holes when the silkworms are parasitic on maggots. The cocoons should be picked and placed gently, and the upper cocoons, lower cocoons and lower cocoons should be placed separately. The picked cocoons should be thinned in a plaque in time, with a thickness of 2-3 cocoons being the best. Too thick will cause heat and affect the cocoon quality.

3. Silkworm disease prevention technology

Disinfection and disease prevention in silkworm breeding is the basis for increasing the yield of silkworm cocoons and the income of silkworm breeding. According to statistics, the proportion of silkworm diseases causing income reduction in silkworm breeding is as high as 70%. To reduce the occurrence of silkworm diseases, disinfection and disease prevention are the key. To do a good job in disinfection and disease prevention in silkworm breeding, we should pay attention to the following:

1. The basic principle of silkworm disease prevention and control is prevention first, combined with fire prevention.

2. Choose the correct method of use according to the disinfectant:

Silkworm houses, utensils, environment, etc. should be soaked or sprayed with clarified bleach containing 1% effective chlorine for disinfection, and kept moist for more than half an hour; airtight silkworm rooms can also be sprayed with a mixture of 2% formalin and 1% lime, and then fumigated with sulfur and cypress, sealed for 24 hours, and left open to dry.

3. Pay attention to disinfection work at all stages of silkworm rearing.

(1) Cleaning and disinfection before silkworm rearing. About a week before silkworm rearing, the silkworm room, silkworm tools, and environment should be cleaned, air-dried, and disinfected with drugs.

(2) Disinfection at each age:

Regularly disinfect the silkworm room and the environment with drugs;

Use "3.7" bran (3 parts lime mixed with 7 parts charred bran) to disinfect silkworms at each age;

When starting silkworms, disinfect the silkworm bodies with silkworm body and silkworm seat disinfectants (use bleaching powder containing 2% effective chlorine to prevent silkworms from becoming stiff when starting silkworms from 1-3 instars, and use bleaching powder containing 3% effective chlorine to prevent silkworms from becoming stiff when starting silkworms from 4-5 instars);

If sick, weak or uncocooned silkworms are found, they should be promptly placed in disinfection tanks and buried in concentrated pits.

During the growth period of silkworms, remove silkworm excrement frequently and spread dry materials such as lime to keep the silkworm bed dry;

Silkworm feces of all ages should not be thrown away or placed randomly, but buried in pits and fermented at high temperature.

(3) Immediate disinfection after silkworm harvesting: Immediately after the cocoon harvesting is completed each season, the silkworm room and silkworm tools must be disinfected, washed, dried, and collected.

Put it in a paper box or a small sieve for sifting rice. If using a sieve, put some paper at the bottom of the sieve.

When the silkworms have just hatched from eggs, you need to be especially careful with them, feed them with relatively tender mulberry leaves, and use a very soft brush to move them when changing mulberry leaves, and pay attention to the strength; sometimes the mulberry leaves are too dry, and if you are not careful, the silkworms will be left on the mulberry leaves that are about to be discarded during the process of changing mulberry leaves. It is a little difficult to raise them when they are young, but it will be easier to handle when they grow up.

When it is about to make a cocoon, just take some wheat straw and tie it into the shape of branches.

After the moths break out of their cocoons, place them together in a box. They will mate together and lay eggs. Sometimes, because there are few silkworms, some moths will be left alone when they break out of their cocoons, but don't worry, as long as you have a pair of silkworms, I believe it will be enough for you to raise.

Mulberry leaves should be fresh. You can also collect them in a plastic bag each time, use a few leaves every day, and sprinkle some water on the rest and put them in the refrigerator to keep them fresh. The collected leaves will have some dust, so you can wash them and dry them. You must dry them, otherwise the young or adult silkworms will have diarrhea after eating them, and they may even die.

Sericulture technology

1. Spray mulberry leaves to feed silkworms: add 5 ml of fermentation liquid to 1 kg of water, spray 10 kg of mulberry leaves to feed them, once a day. Silkworms love to eat, their feces do not stink, they grow fast, their cocoons are thick and of good quality, and they can increase production by about 10%.

2. Spray the silkworms to cool down and relieve heat: In summer, the temperature is high, silkworms are prone to illness, and if the room temperature is too high, silkworms are prone to heatstroke and death. In hot weather, add 5 ml of fermentation liquid to one pound of water and spray it on the silkworms, once in the afternoon and once every day.

3. 3. Spray mulberry leaves to keep them fresh: In summer, the temperature is high, and the collected mulberry leaves will turn yellow and deteriorate if they are piled for a long time. In autumn, the climate is dry, and the collected mulberry leaves will dry out and harden if they are kept for a long time. You can add 5 ml of fermentation liquid to one pound of water, use it to wet the mulberry leaves, then put the mulberry leaves into a woven bag or pile them on the ground, cover them with plastic cloth, and they will still be as fresh and green as before after 24 hours.

4. 4. Spray mulberry leaves to promote growth: add 1-2 ml of fermentation liquid to one pound of water, spray the mulberry leaves in the mulberry field, spray 2-3 times a month, add 0.2% potassium dihydrogen phosphate for better effect. Spray until the mulberry leaves are completely wet without dripping. Mulberry leaves grow fast, the leaves are green and thick, and the yield can be increased by 20-25%. It can also reduce diseases and insect pests.

Note: Antibiotics cannot be used 6 hours before and after using the Vitality 99 Fermentation Agent fermentation liquid. No matter how long the fermentation liquid is stored, as long as it still has a sweet and mellow aroma, it can be used. If it smells, it cannot be used.

What should we pay attention to when raising silkworms in summer and autumn?

1. Prevent pesticide poisoning. During the silkworm-raising season, do not spray the farmland near the silkworm room with organochlorine pesticides such as dimethoate, as the fumigation effect can cause poisoning to the silkworms; mulberry leaves should be fed to the silkworms only after they have been tested and confirmed to be non-toxic.

2. Mosquito-repellent incense or mosquito repellent or insecticide is prohibited in the silkworm room. If it is used in the house near the silkworm room, the doors and windows of the silkworm room should be closed to prevent the silkworms from being poisoned.

3. Screen doors and windows should be installed in the silkworm room to prevent flies from entering the room and harming the silkworms, and "silkworm fly killing" emulsion should be added or sprayed on the silkworm bodies to kill the maggots.

4. Before raising silkworms, rat holes should be blocked, silkworm racks should be kept at a certain distance from the wall, and lime powder or silkworm medicine should be sprinkled around the legs of the silkworm racks to prevent rats from climbing up. When raising silkworms, drugs should be used to kill rats.

5. In summer and autumn, the temperature is high when raising silkworms. Open doors and windows to increase indoor ventilation. Spraying mulberry leaves with clean water and using electric fans to blow breeze indoors can also help cool down the room.

6. If sick silkworms are found, they should be cleaned up in time and placed in a disinfection basin filled with bleach solution or lime slurry. It is forbidden to feed sick silkworms to livestock and poultry to prevent the spread of pathogens and pollute the environment.

7. Silkworm feces contain a large amount of pathogens. Do not spread them out to dry around the silkworm room. Instead, compost them in a pile outdoors or in a manure pit to prevent the spread of pathogens.

8. In summer and autumn, the temperature is high and pathogens multiply quickly. Pay attention to picking leaves on demand, transporting leaves in time, and storing leaves properly. The mulberry pool should be disinfected once for each age, and do not feed mulberry leaves overnight.

9. Avoid feeding wet leaves in hot and humid weather. Do not water the stored mulberry leaves. Remove sand frequently and sprinkle more fresh lime powder, dry straw and other materials to inhibit the growth and reproduction of pathogens.

10. When it is not the silkworm-raising season, do not store grains, bran and other items in the silkworm room to avoid moisture and the generation of mites, which will harm the silkworms during breeding.

What are the tips for raising silkworms and saving mulberry leaves?

Under normal circumstances, 15 kg of mulberry leaves are needed to produce 1 kg of silk cocoons. By taking measures to save mulberry leaves, about 50 kg of mulberry leaves can be saved for each silkworm seed, while the production and quality of silk cocoons will not be affected at all. The measures to save mulberry leaves are:

1. Mulberry leaves should be picked, transported and stored properly. Try to pick leaves in the morning or evening, transport them as soon as they are picked, and pack them loosely for fast transportation. After the picked mulberry leaves are loosened, put them in the mulberry storage pool or mulberry storage room, and store them properly to prevent them from being blown away by the wind or piled up and heated and deteriorated, which will cause waste of mulberry leaves.

2. Prevent mulberry leaves from wilting. During the young silkworm stage, use a kang bed (room) and cover the mulberry leaves with plastic film to keep the temperature and moisture, so that the mulberry leaves remain fresh. During the adult silkworm stage, close the doors and windows appropriately after feeding the silkworms, and then open the doors and windows for ventilation after the silkworms have eaten about 70% of the mulberry leaves, which can effectively prevent the mulberry leaves from wilting.

3. Ensure the temperature of the silkworm room. The suitable temperature for large and small silkworms is 24℃ and 25℃ respectively. Within the suitable temperature range, the silkworms have a strong appetite, which reduces the defective mulberry leaves and improves the leaf-silk conversion rate.

4. Promote less-return rearing and mulberry-strip rearing. Labor-saving silkworm rearing technologies such as flat three-dimensional rearing of small silkworms once a day, rearing of full-age silkworms twice, and rearing of large silkworms in mulberry strips not only improve the efficiency of silkworm rearing, but also help silkworms eat mulberry leaves, saving about 5% of mulberry leaves compared with ordinary rearing.

5. Plan the use of mulberry and feed it in a fixed amount. Set a standard amount of mulberry for each age, day, and period according to the different stages of silkworms, so as to ensure that "the silkworms are well fed and not wasted, and the mulberry is used economically and not starved". At the beginning and end of each age of silkworms, the silkworms consume less mulberry, so feed them leaves in moderation. The silkworms should be fully fed during the peak feeding period of the 5th-age silkworms, but the maximum daily amount of mulberry should be controlled within 110 kg.

6. Add molting hormone. When the silkworms are about 5% mature, use one molting hormone for each seeding sheet, add 25 kg of water, mix with 20 kg of mulberry leaves, and feed them to the silkworms at once. This can help the silkworms mature together, and each seeding sheet can save about 10 kg of mulberry leaves.

How to grasp the key technical links of sleep-wake processing?

The treatment of sleep and wake-up is a very important silkworm breeding technology. Whether it is handled well or not is related to the health status and morbidity of silkworms, as well as the amount of cocoons produced. Therefore, the following technical links should be emphasized:

1. Timely dormancy and weeding. Young silkworms develop quickly, go to sleep quickly, and have a short dormancy period. It is better to put down the dormancy net earlier. The dormancy period of fourth-instar silkworms is long, so it is better to put down the net later. It is better to put down the net earlier in hot and humid weather and later in low and dry weather. It is better to put down the dormancy earlier in the morning and later in the afternoon. When weeding, if there are a small number of (2-3) dormant silkworms on the silkworm nest, sprinkle chaff ash or fresh lime powder (to make the silkworms climb up quickly), add the dormancy net, and give mulberry leaves (the mulberry leaves should be slightly tender when they are ripe). After all the silkworms have climbed up, we can proceed. If we add the dormancy net at night, we should give mulberry leaves once the next morning before dormancy and weeding.

2. Raise the silkworms in batches. After the silkworms are dormant, feed them two mouthfuls of mulberry. When all the silkworms are dormant, there is no need to raise them. The few weak and late-dormant silkworms can be picked out by hand and eliminated. If half of them have not fallen asleep, use the center-batch method to divide the silkworms into two batches to let them sleep. The method is: when half of the silkworms are dormant, add the dormancy net once and feed mulberry evenly, so that the silkworms can climb the net and move to a nest for feeding and then dormant. If the growth and development of the silkworms are uneven, use the center-batch method to separate the large number of silkworms in the dormant state, and raise the early-dormant and late-dormant silkworms in the same nest when the silkworms are raised and fed.

3. Management during sleep. After the silkworms fall asleep, they should be kept quiet, well ventilated, and protected from direct sunlight. In hot and humid weather, chaff ash or lime powder should be sprinkled on the silkworm beds to absorb moisture, which can prevent the growth of pathogens and prevent early-rising silkworms from eating the remaining mulberry leaves and causing uneven development.

4. Feeding at the right time: Feeding should be carried out late, that is, feeding when the silkworms have basically molted and 80-90% of the silkworms have light brown heads. In case of high temperature and sultry weather or white rain, it is advisable to feed early. Generally, feeding should be carried out 5-7 hours after waking. Before feeding at all ages, the silkworm bodies and silkworm seats should be disinfected, and then the nets should be put down and mulberry trees should be used. The mulberry trees should be fresh and tender.

5. Control daytime sleep. To control daytime sleep, the third and fourth sleeps should be the focus. Generally speaking, the third sleep is the daytime sleep, and the big sleep is also the daytime sleep. The third sleep is the night sleep, and the big sleep is also the night sleep. For silkworms that sleep during the day, the mature silkworms will be at noon, so it is convenient to cluster.

How to accelerate the growth of silkworm eggs and harvest silkworm larvae?

The silkworm eggs should be placed in a ventilated bamboo cage or wire rack. Do not use plastic film, cloth or newspaper to pack them to prevent the silkworm eggs from being suffocated. After receiving the seeds, immediately put them in the disinfected silkworm room for protection. Keep the indoor temperature at 22℃ on the 1st to 4th day, and keep it at 25℃ from the 5th day to the hatching period. If the indoor temperature is low in spring, add a brazier to heat up and keep warm (use charcoal, not firewood). The brazier should be more than 1 meter away from the silkworm eggs to avoid drying them to death. Remember to add water to moisten them when adding fire to heat up. On the 8th day of the acceleration, there will be a small black dot on one end of the silkworm eggs, which is called "pointing green". When 20% of the eggs in a sheet of silkworm eggs are point green, wrap the silkworm eggs with newspaper, hold the egg surface down, and shade them to make them black, so that the silkworm eggs develop uniformly. From the day of "pointing green", the eggs will turn green on the second day (the egg surface will be gray), and the ants and silkworms will hatch on the third day. At 5 o'clock in the morning on the day of hatching, remove the shade, turn on the light to sense light, and promote uniform hatching. If there are late-hatching silkworm eggs, continue to shade them and make them black. Then, perform photosensitive ant harvesting at 5 a.m. the next day. Harvest the ants at the end. In spring, when the temperature is low, harvest the ants at around 10 a.m., and in summer and autumn, harvest the ants at around 8 a.m. The mulberry leaves used for harvesting the ants should be picked in the morning of the same day. Mulberry leaves should be selected when they are slightly tender and ripe. The amount of mulberry leaves used is 4-5 times the amount of ants harvested. Method of harvesting the ants: Sprinkle the cut mulberry leaves directly on the silkworm seed paper. After 10-15 minutes, the silkworms will crawl onto the mulberry leaves. Then pour the silkworms and the mulberry leaves onto the silkworm seat paper. Use goose feathers to spread the silkworms evenly. After harvesting the ants, disinfect the ants' bodies when giving the mulberry leaves for the second time. Use "No. 1 Disease Prevention" (special medicine for disinfecting the silkworm bodies, containing 1.25% formaldehyde for small silkworms and 2.5% formaldehyde for large silkworms) and evenly sprinkle the powder on the silkworm bodies in a gauze bag. The amount of medicine should be like a thin layer of frost. After 5 minutes, sprinkle a layer of burnt bran (rice husk burned into black) to separate the powder, and then apply the second round of mulberry leaves.

What first aid measures should be taken when silkworms are poisoned by pesticides?

1. Quickly open doors and windows or move the silkworms to a ventilated place, spread sand-blocking materials, add nets to remove sand, and feed them fresh mulberry leaves.

2. Quickly identify the source of the poison, cut off the source of the poison, and avoid further poisoning.

3. Detoxification: Spray the young silkworms with clean water, wash the adult silkworms with clean water for two minutes, then remove them and dry them in the shade. Some can be revived and fed with fresh leaves; all poisonous utensils are washed with alkaline water and then exposed to the sun. If they can still eat leaves after being poisoned by organophosphorus, they can be given appropriate amounts of atropine.

4. For mildly poisoned silkworms and revived silkworms, nutrition should be strengthened, and suitable mature and tender leaves should be given, and small amounts of feeding should be adopted. A small amount of sugar solution can also be added.

There are very few people raising silkworms now. You can search online to see if there is a silkworm breeding company in your area.

There are very few people raising silkworms now. You can search online to see if there is a silkworm breeding company in your area. If there is, they can provide technology.