CATDOLL : CATDOLL: Where are the best places to raise silkworms? How is the adaptation to the environment? What are the requirements?

Where are the best places to raise silkworms? How is the adaptation to the environment? What are the requirements?

Both greenhouses and cement rooms can be used to raise silkworms (cement rooms are best in cold weather, and greenhouses are best in hot weather). The silkworm room should have a flat and clean floor, with convection windows in the front and back, and preferably ground-level windows. Doors and windows should be equipped with screens to prevent flies, and ground-level windows should be equipped with wire mesh to prevent mice. It takes about 30 square meters of silkworm rearing area and 10 square meters of a special mulberry leaf room to raise one silkworm. The temperature for raising silkworms in summer and autumn is higher, so doors and windows should be opened to increase indoor ventilation. Spraying mulberry leaves with clean water and using electric fans to blow breezes indoors can also help cool down the room.

How to Raise Silkworms

1. Background of the Project

This topic was created purely by chance, in a very natural state, without careful planning in advance. On a spring morning, a little girl in this class brought her own ant silkworms to school to show off to her classmates, which caused an uproar in the class. Most of these children who have lived in matchbox-like buildings since childhood saw and touched the black little creatures crawling on the green mulberry leaves for the first time, which seemed very novel and exciting, and then they had the desire to raise silkworms. The little girl promised to go to her relatives in the countryside to get some silkworms and distribute them to her classmates who share the same hobby as her. The teacher keenly discovered the students' interests and needs, accurately grasped the students' pulse of seeking knowledge, seized this opportunity in time, and made a decisive organization. In this way, a new comprehensive practice activity group came into being, and a new research topic was naturally generated. The purpose of this activity is to satisfy students' exploration psychology of unknown things in their personal experience.

2. Activity plan design

1. Activity theme: Sericulture

2. Activity objectives:

⑴ Cognitive goals:

① Understand the living habits and growth process of silkworms by feeding them.

② Collect information related to silkworms through books, the Internet, and asking others, and learn how to make information cards.

③ Learn to write an observation diary.

⑵ Ability goals:

① Cultivate students' ability to observe things by observing the appearance and changes of silkworms.

② Cultivate students' hands-on ability by feeding silkworms.

⑶Emotional goals:

① Create opportunities for students to get in touch with nature and inspire their love for nature.

② Cultivate students’ willpower to overcome difficulties.

③ Strengthen students’ sense of responsibility and cultivate their beautiful emotions of cherishing small lives.

3.Activity design:

⑴ Make a silkworm breeding box, display it in the group, and select the best "nest" for the silkworms.

⑵ Everyone showed their special abilities to find mulberry leaves and solve the livelihood problem of the silkworms.

⑶ Exchange silkworm-raising experiences and keep the silkworms alive and well.

⑷ Collect relevant information about silkworms by looking up books, surfing the Internet, and asking others, and make information cards.

⑸ Write an observation diary based on the observation of the appearance and growth changes of the silkworms.

⑹Display the results and arrange an oral communication session - "Talking about Silkworm Raising".

2. Implementation of the activity

1. Design and make silkworm boxes by yourself

The members of the silkworm raising group got what they wanted, and got 2 to 6 silkworms of varying numbers, as well as a few mulberry leaves. The silkworm raising activity kicked off, and the first thing to do was to build a comfortable "home" for the silkworms. The group members worked separately, designed and made their own, and each carefully built a comfortable nest for the silkworms, and brought their "nests" to the school for display and evaluation. Most of these "nests" were made of improved paper boxes, and they were filled with the love and wisdom of the children. They were very beautiful, and some were simply exquisite handicrafts. The "nests" had doors and windows that could be opened, painted with gorgeous colors, and matched with cartoon patterns. Some even had greetings for the silkworms written on them. The evaluation conditions were quite harsh, requiring not only a beautiful appearance, but also environmental protection conditions - no odor. I heard that this was a strict regulation made by the silkworm raising group before the silkworm boxes were made, because a group member found out that silkworms would get sick if they smelled odors.

Comment: Today's children have plenty of high-end electronic toys, can play exciting computer games, and watch cartoons episode after episode. However, they rarely come into contact with natural things, such as fishing by the river, catching cicadas with spider webs, and digging amaranth in the suburbs... Most children have never experienced this. Now, letting them feed and care for silkworms by themselves has made up for the missing part of their lives. They find it novel, and this is the motivation that drives them to make efforts, explore, and practice.

(II) Everyone shows off their skills to find mulberry leaves

Silkworms are weak creatures and are very picky about food. Mulberry leaves are their only diet. In a city with tall buildings and asphalt roads, it is not easy to find mulberry leaves. How can we raise silkworms without mulberry leaves? If the silkworms die because they have no mulberry leaves to eat, won’t this vigorous silkworm raising activity become a flash in the pan? Sure enough, within a few days, a student asked the teacher for help: the silkworms have nothing to eat. One child wrote in his diary: I have raised my silkworms for several days. Where did the mulberry leaves come from? At first, the silkworms ate the few pieces of mulberry leaves that Mi Chenyang gave me. Because the silkworms were small, they could still cope with it for several days, but now the silkworms are almost eating up the mulberry leaves. I heard that mulberry leaves are only available in the countryside, and I was extremely anxious. The problem of mulberry leaves is indeed a big problem, which is related to the life and death of silkworms. If the teacher does not care at this time, the silkworms may starve to death, and the silkworm raising group will fall apart; if the teacher takes over to deal with this thorny problem at this time, the activity will lose its autonomy and the children will lose the opportunity to exercise. After repeated consideration, the teacher announced that the mulberry leaves of the silkworms should be provided by the silkworms' first guardian. The result surprised the teacher. All the members of the silkworm-raising group did not let their silkworms go hungry. They showed their talents and got mulberry leaves through various channels. Some were picked by their parents in the suburbs; some were sent by relatives in the countryside by phone; some were picked by neighbors in the yard of the workplace; and some were asked by their own friends in the group. The most interesting thing is that one child actually found a mulberry tree downstairs of his house. Although this mulberry tree has existed for a long time, he did not know it until he raised silkworms this time. Since mulberry leaves are hard to come by, the members of the silkworm-raising group have learned how to preserve mulberry leaves, such as refrigerator preservation method and wet towel preservation method.

Comment: Perhaps it is a professional habit that many primary school teachers like to take care of students like a nanny. In fact, the energy contained in the student group is often suppressed by such monopolization. If teachers believe in students and give them opportunities to display their skills, the talents and abilities shown by students will make us teachers look at them with new eyes. Especially when they have a strong sense of responsibility and take the initiative to do something, the energy they burst out is beyond our expectations.

3. Observe and explore to increase knowledge

The silkworms grow up day by day under the careful feeding of the children. The members of the silkworm raising group often get together to exchange silkworm raising experiences: silkworm feces must be cleaned every day; silkworms have high requirements for hygiene and cannot be touched by dirty hands; silkworms will get sick if they eat mulberry leaves with water... The children have accumulated a lot of experience in silkworm raising, and silkworm raising has entered a stable period. In addition, the children have close contact with silkworms every day and have established a deep relationship with them. At this stage, teachers guide children to observe, discover, and explore, which is undoubtedly striking while the iron is hot. Under the deliberate guidance of the teachers, the children carefully observed the silkworms, wrote observation diaries with great interest, turned over books when encountering problems, searched for information on the Internet, and carefully made knowledge cards. The results are gratifying. The following are excerpts from diaries written by some children:

The silkworm is as thick as my middle finger, with a hint of green in its white and tender skin, and a pair of patterns on its back every few steps. Its mouth is shaped like a figure eight, and it eats mulberry leaves like a razor, shaving off the edges of the leaves one by one...

The eyes of a silkworm are very small and are located on both sides. If you don't look closely, you might think it has no eyes. The silkworm has three pairs of legs in front and four pairs of legs in the back. Its body is soft and cool. When it crawls, it moves like an earthworm, arching its back...

The silkworm baby began to shed its skin again. It first shrank its body, then raised its tail, and a pair of small feet first appeared from under its belly. After a while, it bit the skin with its mouth, shrank its tail, and shed its skin a little more. After an unknown amount of time, it finally took off its old clothes and put on a new white one...

...Sometimes when I touch a silkworm, I find that its body is cool. I wonder why? After checking a book, I found out that silkworms do not have a fixed body temperature. Their body temperature changes with the surrounding temperature. There are many pairs of valves on both sides of the silkworm's body. When the surrounding temperature changes, it uses the method of opening and closing the valves to regulate its body temperature...

Today I searched online for information about silkworms. Why can silkworms produce silk? That is because silkworms absorb nutrients from mulberry leaves and synthesize proteins such as fibroin and sericin in their bodies...

From the above students' diary excerpts, it is not difficult to see that the students are observing with their eyes, experiencing with their emotions, and exploring with their hearts. The gains are so great that there is no need for me to elaborate.

Comment: If the silkworm-raising group's activities only stay at the level of "raising", it will be a great waste of educational resources. At this time, the teacher plays a key role. The teacher's hints, guidance and instruction can help students lead the activities to a deeper level, optimize the activity process, and cultivate students' practical inquiry ability at multiple levels and angles.

(IV) Spring silkworms make cocoons and set up cocoon boxes

In early summer, the silkworms raised by the children went up the mountain to make cocoons. After a period of hard work, the children finally got their rewards and were overjoyed. They brought the white cocoons to school for display, which made the students who did not join the silkworm raising group envious. At this time, the instructor had an idea: in a few days, the silkworm moth will break out of the cocoon and reproduce. If the silkworm seeds are well preserved, when the spring comes next year, larvae will emerge from the silkworm eggs, and then they can be distributed to more children. The silkworm raising group adopted the teacher's suggestion, but the children were immediately stumped by new problems that followed: silkworms that have not mated cannot hatch larvae. What if a classmate's two silkworms are both female or both male? What if the female moth breaks out of the cocoon and lays eggs first? ... Faced with these problems, the members of the silkworm raising group brainstormed and finally came up with a brilliant idea: set up a cocoon collection box in the classroom to put everyone's cocoons together. The new problems were solved easily, and the children's creative thinking was fully reflected.

Comment: When it comes to innovation, some teachers always regard it as too mysterious, and some even associate it with invention. In fact, for primary school students, any new ideas, new perceptions, and new practices that have never been seen before in daily life, study, and practice are innovations. The idea of ​​"setting up cocoon boxes" may be disdainful in the eyes of adults, but for children who have never had the experience of raising silkworms, the process of finding ways and overcoming difficulties by themselves is a process of innovation.

3. Activity Summary

This comprehensive practical activity ended with the children talking about "raising silkworms". In this activity, more than a dozen children experienced the whole process of raising silkworms. Among them, only one child raised a silkworm and it died. The silkworms raised by the other children all survived and produced cocoons. In this activity, the children actively practiced, explored, and acquired knowledge in a broad learning context, covering biology, Chinese, computer networks, labor skills and other subjects, improving their abilities to observe things, discover problems, explore problems, and self-study, and also cultivating innovative thinking and strengthening their sense of responsibility. Its effect is far beyond the reach of closed learning.

Sericulture and breeding technology

1. Key points and standards for raising silkworms

1. Accelerate the growth of silkworms before harvesting. After receiving silkworm eggs, the room temperature is raised to 25-25℃ with a dry-wet difference of 1-2℃. The silkworm eggs are shaded for protection and harvested the next morning. 2. Harvest silkworms at the right time: 8-9 am for spring silkworms and 7-8 am for summer and autumn silkworms. 3. Select good mulberry trees and pick leaves that are ripe. 4. Regulate the target temperature and humidity. Use plastic film to cover the breeding. 5. Strengthen the dormancy and wake-up treatment, strictly divide the silkworms into batches, and eliminate sick and dead silkworms.

Table 1 Standards for raising young silkworms

Order Period

project

One order

Second Order

Three orders

Remark

Purpose(℃)

Dry and wet difference (℃)

27-28

0.5-1

26-27

0.5-1

25-26

1-1.5

Reduced by 0.5-1 during sleep, dry and wet difference during sleep 3-3.5

Zhang Zhong

Amount of mulberry used (kg)

Silkworm bed area (R2)

(Plaque)

1.0

7

(2)

3.0

16

(4)

12.5

40

(5-6)

?

Daily number of times to give mulberry

3-4

3-4

3-4

Cut the mulberry leaves into twice the size of the silkworm body and cut them into triangles.

Ventilation

Combine ventilation with mulberry, and ventilate frequently for 5-10 minutes

Sand removal

No sand removal

Waking up and sleeping once

Eliminate once each when waking up, noon, and sleeping

?

2. Key points and technical standards for silkworm breeding technology

1. Use mulberry leaves economically and reasonably to ensure that the mulberry leaves are good and sufficient for feeding. 2. Rearing methods: choose indoor silkworm plaques (beds), silkworm platforms or plastic greenhouse floor coverings according to local conditions. 3. Prevent and control fly maggot disease. Spray silkworm fly killers at appropriate times.

Table 2 Technical standards for silkworms

Order Period

project

Four Orders

Five Orders

Remark

Purpose(℃)

Dry/Wet Difference(℃)

25

2

23-25

2-2.5

?

Zhang Zhong

Amount of mulberry used (kg)

65

500

?

Silkworm bed area (m2)

11

22-25

?

Daily number of times to give mulberry

4

4-5

In spring, you can pick the three-eyed leaves or buds of mulberry green in the fifth month.

Ventilation

Open doors and windows to raise silkworms

Open doors and windows to raise silkworms

Summer and autumn silkworms should be especially protected from heat and stuffiness

Sand removal

1 time each

1 time per day

Remove 1 time

1-2 times a day

?

3. Strict disinfection and disease prevention:

1. Disinfection before raising silkworms: ⑴ Thorough cleaning: Clean the silkworm room and silkworm tools, and spray lime slurry for disinfection. ⑵ Disinfection with chemicals. Spray the silkworm room and silkworm tools with 1% effective chlorine bleach solution for the first time; use poison dissipation and chlorine-concrete mixture for sealing and fumigation for disinfection for the second time. ⑶ Clean the small silkworm tools, steam and disinfect for half an hour, and spray both sides of the nylon membrane with bleach solution one by one.

2. Disinfection and disease prevention in silkworm rearing: ⑴ Strictly implement the disease prevention and sanitation system. Sprinkle a layer of fresh lime at the door of the silkworm room. Change shoes and wash hands before entering the room. Store the silkworm sand pit away from the silkworm room. Clean the ground after removing the sand from the mulberry tree. Throw dead silkworms into the lime jar. Wrap the dead silkworms and burn them. It is strictly forbidden to feed dead silkworms to chickens. ⑵ Adhere to the use of disease prevention agents. Disinfect the mulberry tree once before collecting the queen ants for the second time and before picking up the silkworms in each order. Use the same disease prevention number or bleaching powder to disinfect the mulberry tree once. After the third order of feeding, use silkworm fly killing and chloramphenicol alternately. ⑶ Strictly separate the green silkworms into batches. Eliminate sick and small silkworms. ⑷ Prevent pesticide poisoning and ensure the quality of mulberry leaves.

3. Post-larvae disinfection: Spray the used silkworm room utensils with lime slurry.

4. Cocooning and Cocoon Harvesting

1. Background of the Project

This topic was created purely by chance, in a very natural state, without careful planning in advance. On a spring morning, a little girl in this class brought her own ant silkworms to school to show off to her classmates, which caused an uproar in the class. Most of these children who have lived in matchbox-like buildings since childhood saw and touched the black little creatures crawling on the green mulberry leaves for the first time, which seemed very novel and exciting, and then they had the desire to raise silkworms. The little girl promised to go to her relatives in the countryside to get some silkworms and distribute them to her classmates who share the same hobby as her. The teacher keenly discovered the students' interests and needs, accurately grasped the students' pulse of seeking knowledge, seized this opportunity in time, and made a decisive organization. In this way, a new comprehensive practice activity group came into being, and a new research topic was naturally generated. The purpose of this activity is to satisfy students' exploration psychology of unknown things in their personal experience.

2. Activity plan design

1. Activity theme: Sericulture

2. Activity objectives:

⑴ Cognitive goals:

① Understand the living habits and growth process of silkworms by feeding them.

② Collect information related to silkworms through books, the Internet, and asking others, and learn how to make information cards.

③ Learn to write an observation diary.

⑵ Ability goals:

① Cultivate students’ ability to observe things by observing the appearance and changes of silkworms.

② Cultivate students' hands-on ability by feeding silkworms.

⑶Emotional goals:

① Create opportunities for students to get in touch with nature and inspire their love for nature.

② Cultivate students’ willpower to overcome difficulties.

③ Strengthen students’ sense of responsibility and cultivate their beautiful emotions of cherishing small lives.

3.Activity design:

⑴ Make a silkworm breeding box, display it in the group, and select the best "nest" for the silkworms.

⑵ Everyone showed their special abilities to find mulberry leaves and solve the livelihood problem of the silkworms.

⑶ Exchange silkworm-raising experiences and keep the silkworms alive and well.

⑷ Collect relevant information about silkworms by looking up books, surfing the Internet, and asking others, and make information cards.

⑸Write an observation diary based on the observation of the appearance and growth changes of the silkworms.

⑹Display the results and arrange an oral communication session - "Talking about Sericulture".

2. Implementation of the activity

1. Design and make silkworm boxes by yourself

The members of the silkworm raising group got what they wanted, and got 2 to 6 silkworms of varying numbers, as well as a few mulberry leaves. The silkworm raising activity kicked off, and the first thing to do was to build a comfortable "home" for the silkworms. The group members worked separately, designed and made their own, and each carefully built a comfortable nest for the silkworms, and brought their "nests" to the school for display and evaluation. Most of these "nests" were made of improved paper boxes, and they were filled with the love and wisdom of the children. They were very beautiful, and some were simply exquisite handicrafts. The "nests" had doors and windows that could be opened, painted with gorgeous colors, and matched with cartoon patterns. Some even had greetings for the silkworms written on them. The evaluation conditions were quite harsh, requiring not only a beautiful appearance, but also environmental protection conditions - no odor. I heard that this was a strict regulation made by the silkworm raising group before the silkworm boxes were made, because a group member found out that silkworms would get sick if they smelled odors.

Comment: Today's children have plenty of high-end electronic toys, can play exciting computer games, and watch cartoons episode after episode. However, they rarely come into contact with natural things, such as fishing by the river, catching cicadas with spider webs, and digging amaranth in the suburbs... Most children have never experienced this. Now, letting them feed and care for silkworms by themselves has made up for the missing part of their lives. They find it novel, and this is the motivation that drives them to make efforts, explore, and practice.

(II) Everyone shows off their skills to find mulberry leaves

Silkworms are weak creatures and are very picky about food. Mulberry leaves are their only diet. In a city with tall buildings and asphalt roads, it is not easy to find mulberry leaves. How can we raise silkworms without mulberry leaves? If the silkworms die because they have no mulberry leaves to eat, won’t this vigorous silkworm raising activity become a flash in the pan? Sure enough, within a few days, a student asked the teacher for help: the silkworms have nothing to eat. One child wrote in his diary: I have raised my silkworms for several days. Where did the mulberry leaves come from? At first, the silkworms ate the few pieces of mulberry leaves that Mi Chenyang gave me. Because the silkworms were small, they could still cope with it for several days, but now the silkworms are almost eating up the mulberry leaves. I heard that mulberry leaves are only available in the countryside, and I was extremely anxious. The problem of mulberry leaves is indeed a big problem, which is related to the life and death of silkworms. If the teacher does not care at this time, the silkworms may starve to death, and the silkworm raising group will fall apart; if the teacher takes over to deal with this thorny problem at this time, the activity will lose its autonomy and the children will lose the opportunity to exercise. After repeated consideration, the teacher announced that the mulberry leaves of the silkworms should be provided by the silkworms' first guardian. The result surprised the teacher. All the members of the silkworm-raising group did not let their silkworms go hungry. They showed their talents and got mulberry leaves through various channels. Some were picked by their parents in the suburbs; some were sent by relatives in the countryside by phone; some were picked by neighbors in the yard of the workplace; and some were asked by their own friends in the group. The most interesting thing is that one child actually found a mulberry tree downstairs of his house. Although this mulberry tree has existed for a long time, he did not know it until he raised silkworms this time. Since mulberry leaves are hard to come by, the members of the silkworm-raising group have learned how to preserve mulberry leaves, such as refrigerator preservation method and wet towel preservation method.

Comment: Perhaps it is a professional habit that many primary school teachers like to take care of students like a nanny. In fact, the energy contained in the student group is often suppressed by such monopolization. If teachers believe in students and give them opportunities to display their skills, the talents and abilities shown by students will make us teachers look at them with new eyes. Especially when they have a strong sense of responsibility and take the initiative to do something, the energy they burst out is beyond our expectations.

3. Observe and explore to increase knowledge

The silkworms grow up day by day under the careful feeding of the children. The members of the silkworm raising group often get together to exchange silkworm raising experiences: silkworm feces must be cleaned every day; silkworms have high requirements for hygiene and cannot be touched by dirty hands; silkworms will get sick if they eat mulberry leaves with water... The children have accumulated a lot of experience in silkworm raising, and silkworm raising has entered a stable period. In addition, the children have close contact with silkworms every day and have established a deep relationship with them. At this stage, teachers guide children to observe, discover, and explore, which is undoubtedly striking while the iron is hot. Under the deliberate guidance of the teachers, the children carefully observed the silkworms, wrote observation diaries with great interest, turned over books when encountering problems, searched for information on the Internet, and carefully made knowledge cards. The results are gratifying. The following are excerpts from diaries written by some children:

The silkworm is as thick as my middle finger, with a hint of green in its white and tender skin, and a pair of patterns on its back every few steps. Its mouth is shaped like a figure eight, and it eats mulberry leaves like a razor, shaving off the edges of the leaves one by one...

The eyes of a silkworm are very small and are located on both sides. If you don't look closely, you might think it has no eyes. The silkworm has three pairs of legs in front and four pairs of legs in the back. Its body is soft and cool. When it crawls, it moves like an earthworm, arching its back...

The silkworm baby began to shed its skin again. It first shrank its body, then raised its tail, and a pair of small feet first appeared from under its belly. After a while, it bit the skin with its mouth, shrank its tail, and shed its skin a little more. After an unknown amount of time, it finally took off its old clothes and put on a new white one...

...Sometimes when I touch a silkworm, I find that its body is cool. I wonder why? After checking a book, I found out that silkworms do not have a fixed body temperature. Their body temperature changes with the surrounding temperature. There are many pairs of valves on both sides of the silkworm's body. When the surrounding temperature changes, it uses the method of opening and closing the valves to regulate its body temperature...

Today I searched online for information about silkworms. Why can silkworms produce silk? That is because silkworms absorb nutrients from mulberry leaves and synthesize proteins such as fibroin and sericin in their bodies...

From the above students' diary excerpts, it is not difficult to see that the students are observing with their eyes, experiencing with their emotions, and exploring with their hearts. The harvest is so great that I don't need to elaborate on it.

Comment: If the silkworm-raising group's activities only stay at the level of "raising", it will be a great waste of educational resources. At this time, the teacher plays a key role. The teacher's hints, guidance and instruction can help students lead the activities to a deeper level, optimize the activity process, and cultivate students' practical inquiry ability at multiple levels and angles.

(IV) Spring silkworms make cocoons and set up cocoon boxes

In early summer, the silkworms raised by the children went up the mountain to make cocoons. After a period of hard work, the children finally got their rewards and were overjoyed. They brought the white cocoons to school for display, which made the students who did not join the silkworm raising group envious. At this time, the instructor had an idea: in a few days, the silkworm moth will break out of the cocoon and reproduce. If the silkworm seeds are well preserved, when the spring comes next year, larvae will emerge from the silkworm eggs, and then they can be distributed to more children. The silkworm raising group adopted the teacher's suggestion, but the children were immediately stumped by new problems that followed: silkworms that have not mated cannot hatch larvae. What if a classmate's two silkworms are both female or both male? What if the female moth breaks out of the cocoon and lays eggs first? ... Faced with these problems, the members of the silkworm raising group brainstormed and finally came up with a brilliant idea: set up a cocoon collection box in the classroom to put everyone's cocoons together. The new problems were solved easily, and the children's creative thinking was fully reflected.

Comment: When it comes to innovation, some teachers always regard it as too mysterious, and some even associate it with invention. In fact, for primary school students, any new ideas, new perceptions, and new practices that have never been seen before in daily life, study, and practice are innovations. The idea of ​​"setting up cocoon boxes" may be disdainful in the eyes of adults, but for children who have never had the experience of raising silkworms, the process of finding ways and overcoming difficulties by themselves is a process of innovation.

3. Summary of the activity

This comprehensive practical activity ended with the children talking about "raising silkworms". In this activity, more than a dozen children experienced the whole process of raising silkworms. Among them, only one child raised a silkworm and it died. The silkworms raised by the other children all survived and produced cocoons. In this activity, the children actively practiced, explored, and acquired knowledge in a broad learning context, covering biology, Chinese, computer networks, labor skills and other subjects, improving their abilities to observe things, discover problems, explore problems, and self-study, and also cultivating innovative thinking and strengthening their sense of responsibility. Its effect is far beyond the reach of closed learning.

Sericulture and breeding technology

1. Key points and standards for raising silkworms

1. Accelerate the growth of silkworms before harvesting. After receiving silkworm eggs, the room temperature is raised to 25-25℃ with a dry-wet difference of 1-2℃. The silkworm eggs are shaded for protection and harvested the next morning. 2. Harvest silkworms at the right time: 8-9 am for spring silkworms and 7-8 am for summer and autumn silkworms. 3. Select good mulberry trees and pick leaves that are ripe. 4. Regulate the target temperature and humidity. Use plastic film to cover the breeding. 5. Strengthen the dormancy and wake-up treatment, strictly divide the silkworms into batches, and eliminate sick and dead silkworms.

Table 1 Standards for raising young silkworms

Order Period

project

One order

Second Order

Three orders

Remark

Purpose(℃)

Dry/Wet Difference(℃)

27-28

0.5-1

26-27

0.5-1

25-26

1-1.5

Reduced by 0.5-1 during sleep, dry and wet difference during sleep 3-3.5

Zhang Zhong

Amount of mulberry used (kg)

Silkworm bed area (R2)

(Plaque)

1.0

7

(2)

3.0

16

(4)

12.5

40

(5-6)

?

Daily number of times to give mulberry

3-4

3-4

3-4

Cut the mulberry leaves into twice the size of the silkworm body and cut them into triangles.

Ventilation

Combine ventilation with mulberry, and ventilate frequently for 5-10 minutes

Sand removal

No sand removal

Waking up and sleeping each time

Eliminate once each when waking up, noon, and sleeping

?

2. Key points and technical standards for silkworm breeding technology

1. Use mulberry leaves economically and reasonably to ensure that the mulberry leaves are good and sufficient for feeding. 2. Rearing methods: choose indoor silkworm plaques (beds), silkworm platforms or plastic greenhouse floor coverings according to local conditions. 3. Prevent and control fly maggot disease. Spray silkworm fly killers at appropriate times.

Table 2 Technical standards for silkworms

Order Period

project

Four Orders

Five Orders

Remark

Purpose(℃)

Dry/Wet Difference(℃)

25

2

23-25

2-2.5

?

Zhang Zhong

Amount of mulberry used (kg)

65

500

?

Silkworm bed area (m2)

11

22-25

?

Daily number of times to give mulberry

4

4-5

In spring, you can pick the three-eyed leaves or buds of mulberry green in the fifth month.

Ventilation

Open doors and windows to raise silkworms

Open doors and windows to raise silkworms

Summer and autumn silkworms should be especially protected from heat and stuffiness

Sand removal

1 time each

1 time per day

Remove 1 time

1-2 times a day

?

3. Strict disinfection and disease prevention:

1. Disinfection before raising silkworms: ⑴ Thorough cleaning: Clean the silkworm room and silkworm tools, and spray lime slurry for disinfection. ⑵ Disinfection with chemicals. Spray the silkworm room and silkworm tools with 1% effective chlorine bleach solution for the first time; use poison dissipation and chlorine-concrete mixture for sealing and fumigation for disinfection for the second time. ⑶ The small silkworm tools should be cleaned and boiled for disinfection for half an hour. The nylon membrane should be sprayed on both sides with bleach solution one by one.

2. Disinfection and disease prevention in silkworm rearing: ⑴ Strictly implement the disease prevention and sanitation system. Sprinkle a layer of fresh lime at the door of the silkworm room. Change shoes and wash hands before entering the room. Store the silkworm sand pit away from the silkworm room. Clean the ground after removing the sand from the mulberry tree. Throw dead silkworms into the lime jar. Wrap the dead silkworms and burn them. It is strictly forbidden to feed dead silkworms to chickens. ⑵ Adhere to the use of disease prevention agents. Disinfect the mulberry tree once before collecting the queen ants for the second time and before picking up the silkworms in each order. Use the same disease prevention number or bleaching powder to disinfect the mulberry tree once. After the third order of feeding, use silkworm fly killing and chloramphenicol alternately. ⑶ Strictly separate the green silkworms into batches. Eliminate sick and small silkworms. ⑷ Prevent pesticide poisoning and ensure the quality of mulberry leaves.

3. Post-larvae disinfection: Spray the used silkworm room utensils with lime slurry.

4. Cocooning and Cocoon Harvesting

1. Background of the Project

This topic was created purely by chance, in a very natural state, without careful planning in advance. On a spring morning, a little girl in this class brought her own ant silkworms to school to show off to her classmates, which caused an uproar in the class. Most of these children who have lived in matchbox-like buildings since childhood saw and touched the black little creatures crawling on the green mulberry leaves for the first time, which seemed very novel and exciting, and then they had the desire to raise silkworms. The little girl promised to go to her relatives in the countryside to get some silkworms and distribute them to her classmates who share the same hobby as her. The teacher keenly discovered the students' interests and needs, accurately grasped the students' pulse of seeking knowledge, seized this opportunity in time, and made a decisive organization. In this way, a new comprehensive practice activity group came into being, and a new research topic was naturally generated. The purpose of this activity is to satisfy students' exploration psychology of unknown things in their personal experience.

2. Activity plan design

1. Activity theme: Sericulture

2. Activity objectives:

⑴ Cognitive objectives:

① Understand the living habits and growth process of silkworms by feeding them.

② Collect information related to silkworms through books, the Internet, and asking others, and learn how to make information cards.

③ Learn to write an observation diary.

⑵ Ability goals:

① Cultivate students’ ability to observe things by observing the appearance and changes of silkworms.

② Cultivate students' hands-on ability by feeding silkworms.

⑶Emotional goals:

① Create opportunities for students to get in touch with nature and inspire their love for nature.

② Cultivate students’ willpower to overcome difficulties.

③ Strengthen students’ sense of responsibility and cultivate their beautiful emotions of cherishing small lives.

3.Activity design:

⑴ Make a silkworm breeding box, display it in the group, and select the best "nest" for the silkworms.

⑵ Everyone showed their special abilities to find mulberry leaves and solve the livelihood problem of the silkworms.

⑶ Exchange silkworm-raising experiences and keep the silkworms alive and well.

⑷ Collect relevant information about silkworms by looking up books, surfing the Internet, and asking others, and make information cards.

⑸ Write an observation diary based on the observation of the appearance and growth changes of the silkworms.

⑹Display the results and arrange an oral communication session - "Talking about Silkworm Raising".

2. Implementation of the activity

1. Design and make silkworm boxes by yourself

The members of the silkworm raising group got what they wanted, and got 2 to 6 silkworms of varying numbers, as well as a few mulberry leaves. The silkworm raising activity kicked off, and the first thing to do was to build a comfortable "home" for the silkworms. The group members worked separately, designed and made their own, and each carefully built a comfortable nest for the silkworms, and brought their "nests" to the school for display and evaluation. Most of these "nests" were made of improved paper boxes, and they were filled with the love and wisdom of the children. They were very beautiful, and some were simply exquisite handicrafts. The "nests" had doors and windows that could be opened, painted with gorgeous colors, and matched with cartoon patterns. Some even had greetings for the silkworms written on them. The evaluation conditions were quite harsh, requiring not only a beautiful appearance, but also environmental protection conditions - no odor. I heard that this was a strict regulation made by the silkworm raising group before the silkworm boxes were made, because a group member found out that silkworms would get sick if they smelled odors.

Comment: Today's children have plenty of high-end electronic toys, can play exciting computer games, and watch cartoons episode after episode. However, they rarely come into contact with natural things, such as fishing by the river, catching cicadas with spider webs, and digging amaranth in the suburbs... Most children have never experienced this. Now, letting them feed and care for silkworms by themselves has made up for the missing part of their lives. They find it novel, and this is the motivation that drives them to make efforts, explore, and practice.

(II) Everyone shows off their abilities to find mulberry leaves

Silkworms are weak creatures and are very picky about food. Mulberry leaves are their only diet. In a city with tall buildings and asphalt roads, it is not easy to find mulberry leaves. How can we raise silkworms without mulberry leaves? If the silkworms die because they have no mulberry leaves to eat, won’t this vigorous silkworm raising activity become a flash in the pan? Sure enough, within a few days, a student asked the teacher for help: the silkworms have nothing to eat. One child wrote in his diary: I have raised my silkworms for several days. Where did the mulberry leaves come from? At first, the silkworms ate the few pieces of mulberry leaves that Mi Chenyang gave me. Because the silkworms were small, they could still cope with it for several days, but now the silkworms are almost eating up the mulberry leaves. I heard that mulberry leaves are only available in the countryside, and I was extremely anxious. The problem of mulberry leaves is indeed a big problem, which is related to the life and death of silkworms. If the teacher does not care at this time, the silkworms may starve to death, and the silkworm raising group will fall apart; if the teacher takes over to deal with this thorny problem at this time, the activity will lose its autonomy and the children will lose the opportunity to exercise. After repeated consideration, the teacher announced that the mulberry leaves of the silkworms should be provided by the silkworms' first guardian. The result surprised the teacher. All the members of the silkworm-raising group did not let their silkworms go hungry. They showed their talents and got mulberry leaves through various channels. Some were picked by their parents in the suburbs; some were sent by relatives in the countryside by phone; some were picked by neighbors in the yard of the workplace; and some were asked by their own friends in the group. The most interesting thing is that one child actually found a mulberry tree downstairs of his house. Although this mulberry tree has existed for a long time, he did not know it until he raised silkworms this time. Since mulberry leaves are hard to come by, the members of the silkworm-raising group have learned how to preserve mulberry leaves, such as refrigerator preservation method and wet towel preservation method.

Comment: Perhaps it is a professional habit. Many primary school teachers like to take on students like nanny. In fact, the energy contained in the student group is often restrained by such a snatch. If teachers believe in students and give students the opportunity to display their abilities, the talents and abilities shown by students will be admired by our teachers. Especially when they have a strong sense of responsibility and take the initiative to do something, the bursting energy is unexpected to us teachers.

(III) Observation and exploration, increase knowledge

Silkworms grow up day by day under the careful feeding of children. Members of the silkworm breeding group often gather together to exchange experiences in silkworm breeding: silkworm sand should be cleaned every day; silkworms have high hygiene requirements and cannot touch it with dirty hands; silkworms will get sick if they eat mulberry leaves with water... Children have accumulated a lot of experience in raising silkworms, and silkworms have entered a stable period. In addition, children have close contact with silkworms every day and have established deep feelings. At this stage, the teachers guide children to observe, discover and explore, undoubtedly strike while the iron is hot. Under the deliberate guidance of the teacher, the children carefully observe the silkworms, write observation diaries with great enthusiasm, read books when they encounter problems, search for information on the Internet, and carefully make knowledge cards. The result is gratifying. The following are the diary fragments written by some children:

The silkworm is about thick and long as my middle finger, and the white and tender skin is full of blue. Every part of its back has a pair of patterns. Its mouth is in a 8-shaped shape, and it tastes like a razor, shaving it one by one from the edge of the mulberry leaves...

The silkworm's eyes are very small and grow on both sides. If you don't look carefully, you will think you don't have eyes. There are three pairs of feet in front of the silkworm and four pairs of feet in the back. Its body is soft and cool. It is similar to an earthworm when crawling, arching one by one...

The silkworm began to shed its skin again. It first tightened its body, then thrust its tail, and a pair of small feet first exposed from under its belly. After a while, it bit the skin with its mouth again, and its tail shrank, and the skin was a little wet. I don’t know how long it took, but it finally took off its old clothes and changed into a white new dress...

...Sometimes when I touch the silkworm, I find that it is cold. I don’t know why? After checking the book, I realized that the silkworm has no fixed body temperature, and its body temperature will change with the surrounding temperature. There are many pairs of valves on both sides of the silkworm’s body. Once the temperature around it changes, it uses the method of opening and closing the valve to adjust the body temperature...

Today I found information about silkworms online. Why can silkworms spit out silk? That is because silkworms absorb nutrients from mulberry leaves and synthesize silkworms, sericin and other proteins in their bodies...

From the above diary fragments of students, it is not difficult to see that students are observing with their eyes, experiencing with their emotions, and exploring with their hearts. The great gains do not need to be explained by the author.

Commentary: If the activities of the silkworm breeding group are only at the level of "raising", it will greatly waste educational resources. At this time, teachers play a key role. Teachers' hints, guidance and guidance can help students lead the activities to a depth, optimize the activity process, and cultivate students' practical exploration abilities at multiple levels and angles.

(IV) Spring silkworms make cocoons and set up cocoon boxes

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Comment: When it comes to innovation, some teachers always regard it as too mysterious, and some even more related it to creation and invention. In fact, for primary school students, in daily life, study, and practice, any new ideas, new insights, and new practices that have never been seen before are innovation. The idea of ​​"setting up a cocoon box" may be disdainful to adults, but for children who have never had the experience of raising silkworms, the process of finding ways to overcome difficulties by themselves is an innovation process.

3. Activity summary

This comprehensive practical activity ended with the children's talk about "silk cultivation". In this activity, more than ten children experienced the entire process of silkworm breeding. Among them, only one child raised a silkworm to death. The other children raised silkworms all survived and formed cocoons. In this activity, the children actively practiced, explored and grabbed knowledge in a broad learning background, and dabbled in a variety of disciplines such as biology, Chinese, computer networks, and labor technology. They improved their abilities to observe things, discover problems, explore problems, and self-learning, and cultivated innovative thinking and strengthened their sense of responsibility. The effect is far from comparable to closed learning.

Silkworm breeding technology

1. Key points and feeding standards for small silkworm feeding

1. Replenish green before harvesting ants. After the silkworm seeds are harvested, the room temperature rises to 25-25℃ and the dry and wet difference is 1-2℃. The silkworm seeds are shading and protected, and the next morning is light-sensitive to harvest ants. 2. Recover ants in time: spring silkworms are 8-9 am, and summer and autumn silkworms are 7-8 am. 3. Select good mulberry and pick mature leaves. 4. Regulate the temperature and humidity of the purpose. Cover and breed with plastic film. 5. Strengthen sleeping treatment, strictly divide into batches, and eliminate dead silkworms.

Table 1 Silkworm breeding standards

Lingqi

project

One order

Second order

Three orders

Remark

Degree of purpose (℃)

Dry and wetness difference (℃)

27-28

0.5-1

26-27

0.5-1

25-26

1-1.5

Reduce 0.5-1 during sleep, dry and wetness difference between sleep, 3-3.5

Zhang Zhong

Mulberry quantity (kg)

Silkworm seat area (R2)

(Plalate)

1.0

7

(2)

3.0

16

(4)

12.5

40

(5-6)

?

Daily replies

3-4

3-4

3-4

Cut mulberry leaves into silkworms twice square three orders into triangular leaves into chicken feet

Ventilation

Combined ventilation when giving mulberry, and regularly breathe for 5-10 minutes

Sand removal

No sand removal

Get up and sleep once

Get up, middle, and sleep once

?

2. Key points and technical standards for feeding silkworms

1. Use mulberry trees economically and reasonably to ensure that good mulberry trees are full. 2. Feeding method: Choose indoor silkworm plaques (beds) to breed, silkworm platform or plastic greenhouse floor clothes according to local conditions. 3. Prevent and treat myiasis. Spray silkworm and fly-killing agents in time.

Table 2 Technical standards for silkworms

Lingqi

project

Four orders

Five Orders

Remark

Degree of purpose (℃)

Dry and wetness difference (℃)

25

2

23-25

2-2.5

?

Zhang Zhong

Mulberry quantity (kg)

65

500

?

Silkworm seat area (m2)

11

22-25

?

Daily replies

4

4-5

In spring, you can pick mulberry green, four or three eye leaves or bud leaves

Ventilation

Open doors and windows to raise silkworms

Open doors and windows to raise silkworms

Summer and autumn silkworms should be particularly hot and stuffy

Sand removal

Sleep once each

Discard once a day

Get rid of 1 time

1-2 times a day

?

3. Strict disinfection and disease prevention:

1. Disinfection before raising silkworms: ⑴ Clean thoroughly: Clean the silkworms in the silkworms and spray them with lime mortar to disinfect. ⑵ Disinfection of the agent. The first time, spray the silkworms and silkworms with 1% effective chlorine bleach; the second time, dissipate them with toxicity, and seal the chlorine concrete mixture to smoke and disinfect. ⑶ Clean the small silkworms and swallow them, steam and disinfect for half an hour, and spray the nylon membrane with bleaching liquid on both sides.

2. Disinfection and disease prevention during silkworm raising: ⑴ Strictly control the disease and sanitation system, sprinkle a layer of fresh lime at the door of the silkworm room, change shoes and wash hands. Silkworm sand pits are piled away from the silkworm room. Clean the ground after removing sand, throw the dead silkworm into the lime tank, and burn it. It is strictly forbidden to feed the dead silkworm chickens. ⑵ Adhere to the use of disease prevention agents. Before the ants are collected, the silkworm will be given the same number of disease prevention or bleaching powder to disinfect it once. After eating, the silkworm will be killed and chlorine-toxic. ⑶ Strictly improve the green and divide the disease into batches. Eliminate disease and small silkworms. ⑷ Prevent pesticide poisoning and ensure the quality of mulberry leaves.

3. Disinfection after silkworms: Spray the used silkworm chamber tools thoroughly with lime mortar.

4. Top clusters and cocoons