CATDOLL : CATDOLL: Why do fifth-instar silkworms die inexplicably?

1. Why do fifth-instar silkworms die inexplicably?

1. Environmental reasons, such as hygiene. If the silkworm room is not cleaned, the mortality rate will be very high. The silkworm room must be cleaned and the feed must be clean and hygienic.

2. Temperature reasons: the development temperature is 7-40°C, and the suitable temperature for breeding is 20-30°C. Too low or too high temperature will lead to death.

3. Causes of diseases: infectious diseases or parasitic pests. In current production, infectious silkworm diseases, fungal diseases and bacterial diseases are more common and more harmful.

4. Chemical death: Silkworms die of poisoning due to the abuse of pesticides. Non-infectious silkworm diseases are mainly caused by pesticide poisoning, industrial waste gas poisoning and environmental pollution.

If the silkworms die inexplicably, it could be because the temperature is too high or too low, or the silkworm breeder has not taken good care of the silkworms.

2. Should the lime on the white silkworm be washed clean?

A: Don't wash it. The lime on the white silkworm is not real lime, but a kind of fungus. It is a disease caused by Beauveria bassiana invading the silkworm body. Symptoms: In the early stage of the infection of Beauveria bassiana, the appearance of the silkworm is no different from that of the healthy silkworm, except that the body color is slightly darker and the reaction is slow. As the disease progresses, dark brown spots like oil stains appear on the skin of the diseased silkworm. After the silkworm dies, it becomes soft first and then hard, and its whole body is covered with white conidia.

3. What factors should be paid attention to when raising silkworms?

Those who have raised silkworms know that pesticides have a great impact on silkworms. Mild pesticides will affect the quality and yield of silkworm cocoons, easily induce some silkworm diseases, and more serious ones will lead to total crop failure, which is a big blow to farmers. In order to avoid such phenomena, farmers should pay special attention when picking and feeding mulberry leaves. Once the silkworms are found to have symptoms of poisoning, they should analyze the causes and take timely countermeasures. In order to avoid the symptoms of pesticide poisoning in silkworms, it is necessary to understand clearly what factors may cause this phenomenon. There are mainly four points.

1. The layout of the mulberry garden plot is inappropriate

In the hilly areas of the south, arable land resources are relatively scarce, and the plots allocated to each family are relatively scattered. For example, in our village, it is rare for a plot to exceed 5 mu, and most of them are less than 3 mu. Plots with better fertility are often paired with relatively poor plots, which brings great challenges to planting mulberry trees. In some plots, your family has planted mulberry trees, while the surrounding plots are rice fields, fruit trees, vegetable fields, etc. There are great hidden dangers in building mulberry gardens on such plots, and it is easy for silkworms to be poisoned by pesticides. After all, when other people's plots have insect pests and need to use pesticides, it is difficult for farmers to stop them. Sometimes you may be very careful when applying pesticides, but when the wind blows, the pesticides will be on the mulberry leaves invisibly. Silkworms eat mulberry leaves with pesticides, which can easily cause poisoning.

2. Excessive use of pesticides in mulberry fields and weak awareness of anti-poisoning

In addition to the use of pesticides on crops around the mulberry garden, pesticides are also used to eliminate pests and weeds inside the mulberry garden, especially for large mulberry gardens where manual weeding is unlikely. Some farmers do not strictly follow the instructions when using pesticides in mulberry gardens, and some farmers use the same pesticide for a long time, which is prone to drug resistance. Farmers think that the effect is not obvious, so they increase the amount of pesticides used, which is prone to pesticide residues. Silkworms eating such mulberry leaves will naturally have a significant impact.

3. Pesticide quality does not meet standards and contains hidden ingredients

Nowadays, there are many varieties of pesticides, some are new products, and some may be obsolete products. When farmers buy pesticides, it is difficult to tell which one is suitable. Basically, they look at the price first, and then listen to the recommendation of the salesperson. Some pesticides do not have complete ingredients, or the salesperson does not explain clearly, and there is a certain degree of concealment. Some pesticides themselves do not meet the quality standards. On the surface, they are written as safe and controllable, but in fact they bring some uncontrollable factors. When such pesticides are used in mulberry gardens, silkworms are prone to pesticide poisoning symptoms when they eat such mulberry leaves.

4. Pesticides that are highly toxic or extremely toxic to silkworms are used in mulberry gardens, and there are chemical factories nearby.

Since silkworms have high requirements for mulberry leaves, there cannot be insect eggs on the leaves. This also puts higher requirements on mulberry garden management, and it is necessary to do a good job in mulberry garden pest control. In many cases, in order to save trouble and reduce costs, farmers often use drugs for prevention and control. There will be obvious effects in a short time, but it will also bring some disadvantages. When using drugs, many farmers are not very clear about which drugs cannot be used and which drugs cannot be mixed. Some drugs

4. What should I pay attention to when raising silkworms? When should I change the mulberry leaves? When does it mean that the silkworms are sick?

I hope my answer can help you.

Usually, silkworms are raised indoors on the ground and outdoors on scaffolds during the silkworm raising season. When raising silkworms, 5 ml of fermentation liquid can be added to one catty of water, and 10 catties of mulberry leaves can be sprayed to add food. Screen doors and windows should be installed in the silkworm room, and sick silkworms should be cleaned up in time. In spring and summer, the growth cycle of mulberry trees should be roughly the same to ensure an adequate supply of mulberry leaves.

How to raise silkworms

1. Rearing method: 4-5-year-old silkworms are in the adult stage, and the suitable growth temperature is 25 degrees. Silkworms have weak resistance to high temperature, humidity and carbon dioxide, eat a lot of mulberry leaves and excrete a lot. They can be raised on the ground indoors or on outdoor sheds.

2. After receiving the silkworm eggs, protect them in a suitable environment to allow the embryos to develop normally. The specific method is: in a disinfected silkworm room, spread the silkworm eggs flat on the silkworm plaque with the eggs facing upward. The room temperature should be 24℃ and the dry-wet difference should be 2-2.5℃ for the first 4 days. The room temperature should be 27℃ and the dry-wet difference should be 1.5-2℃ for the fifth to tenth days. When the embryos develop to the later stage and a small number of silkworm eggs are found to be blue dots, immediately cover the silkworm eggs with black cloth. After about 40 hours, that is, 4-5 o'clock before dawn on the third day, remove the black cloth, wrap the silkworm eggs with white paper, with the eggs facing upward, turn on the light to let the ants bite through the egg shells and hatch.

3. The main technical measures for raising silkworms are:

⑴ Improve the environment and ensure ventilation to prevent stuffiness.

⑵ Build a shed to provide shade and prevent hot air from entering the silkworm room.

⑶ The silkworm seats should be placed sparsely and low, and fed frequently and in small amounts.

⑷ Pay close attention to the management of the mulberry garden, ensure the quantity and quality of mulberry leaves at the fifth age, so that the silkworms can be well fed and eat well, and prevent the silkworms from eating old and hard leaves, too tender leaves, malnourished leaves, and leaves that lack water.

Details to pay attention to when raising silkworms

1. Remove sand before dormancy. This is to avoid excessive accumulation of silkworm feces, which can easily breed and spread pathogens and invade the silkworms during their dormancy.

2. Silkworms do not eat or move during the dormant period. They mainly rely on the nutrients absorbed by eating mulberry before dormancy to maintain their life activities. Therefore, they must sleep when they are full. If you stop feeding mulberry too early, they will starve to sleep. Starved silkworms are weak in constitution, poor in resistance, and prone to illness.

3. Silkworms have weak resistance to various external interferences during their hibernation period, so it is important to pay attention to their protection during sleep.

When 95% of the silkworms have settled, fresh lime powder and silkworm medicine "Disease Prevention No. 1" should be sprinkled on them to prevent pathogens from invading. If a small number of silkworms do not eat mulberry and do not settle, it is because they have not found a place to settle. At this time, some mulberry leaves should be added to settle the silkworms in batches.

4. Silkworms are temperature-changing animals, and their adaptability range is 20-30℃. In the spring silkworm period, the climate is often low and humid, so the focus is on replenishing warmth and removing moisture. In the summer silkworm period, the climate is hot and humid, so the focus is on cooling and removing moisture, keeping the air in the silkworm room flowing, and removing the stuffiness. In the autumn silkworm period, if the climate is hot and dry, it is necessary to replenish moisture indoors and combine disinfection, that is, spray the ground and walls with fresh lime powder and bleaching powder; you can also hang a wet cloth on the silkworm rack to keep the silkworm room moist to prevent the silkworms from having difficulty molting or half molting.

Silkworm breeding 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 are not smelly, 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. Spray mulberry leaves to keep them fresh: In summer, when the temperature is high, the collected mulberry leaves will turn yellow and deteriorate if they are piled for a long time. In autumn, when the climate is dry, the collected mulberry leaves will dry out and become hard 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 remain as fresh and green as before after 24 hours.

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.

Precautions for 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 will 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.