Integrated control of infectious silkworm disease

In the process of infectious silkworm disease, the cocoon is not harvested and the cocoon quality is reduced. Therefore, disinfection and disease prevention must run through the whole process of sericulture. On the basis of focusing on the disinfection before sericulture, we should do a good job in disease prevention and disinfection after sericulture, and carry out comprehensive prevention and control in order to completely eliminate bacteria and put an end to the occurrence of infectious silkworm diseases.

First, eliminate diseased silkworms in time. Many infectious silkworm diseases, such as midgut purulent disease, viral malacia, particle disease, bacterial gastrointestinal disease and so on. At the initial stage of infection with the above diseases, silkworms often show symptoms such as growth retardation, thin silkworm body, uneven development and so on. At this time, there have been a large number of highly virulent pathogenic microorganisms, through the feces and digestive juices of diseased silkworms to pollute mulberry leaves and silkworm seats, which is one of the important reasons for the outbreak of silkworm disease.

Practice has proved that large and small silkworms rearing in the same room often cause a large incidence of silkworm disease in later batches of silkworms. If diseased silkworms are found as soon as possible, young silkworms are reared in separate rooms, and personnel, silkworm rooms and silkworm tools are used exclusively, it can not only improve the level of rearing, but also is an important measure to prevent silkworm disease.

Second, the silkworm body silkworm seat disinfection. The pathogenic microorganisms that pollute the silkworm pedestal are mainly from the feces, digestive juices or body fluids of diseased silkworms. In addition, the outdoor pathogenic microorganisms brought into the room with mulberry leaves, sericulture utensils or breeders can also flow with the air and fall on the silkworm seat with dust. Therefore, regular disinfection of silkworm pedestal can kill pathogenic microorganisms immediately, which is an important measure to prevent the occurrence of silkworm disease.

At present, there are three kinds of disinfectants, fumigants and liquids commonly used in silkworm production. The powder mainly includes lime powder, bleach powder, anti-stiff powder, anti-disease No. 1, silkworm seat net, etc.; liquid agent has Fangzhiling No. 2; fumigant has Youchujing and so on. These agents are generally used once a day from the harvest of silkworms, and increased in the areas and seasons where rigidity often occurs in the feeding period of each age. When a stiff disease has occurred, use it once a day for several days until it no longer occurs.

Fresh lime powder is the most widely used, economical and effective disinfectant in sericulture. It is usually used once a day from the third age. When the silkworm disease has occurred, first of all, strictly pick up the diseased young silkworm, and appropriately increase the number of use.

In addition to disease No. 1, there are two kinds of silkworms: small silkworm and big silkworm. In general, the ant silkworm and each instar silkworm are used once, and can be used once a day when silkworm disease occurs. Spread evenly on the silkworm seat wrapped with gauze, it is appropriate to cover the silkworm seat and the surface of silkworm body with a thin layer of frost, and the usage increases with the increase of silkworm age. Keep the silkworm seat dry when in use, do not wet mulberry leaves.

The usage of silkworm seat net is the same as that of Fangdi No.1.

Bleach can also be mixed with lime powder to form an anti-rigidity powder containing available chlorine of 2% (for small silkworms) or 3% (for large silkworms). The usage is the same as that of disease prevention No. 1, but pay attention to the present use and remove sand immediately after use.

Third, disease prevention measures in sericulture operation. The disease prevention measures in the process of sericulture operation are as follows: ⑴ unsterilized silkworm tools, prohibited to be brought into the silkworm room. The appliances for transporting silkworm sand in ⑵ are strictly separated from those for transporting mulberry leaves. The silkworm net after sand removal by ⑶ is often exposed to the sun and disinfected. ⑷ enters the silkworm room and mulberry storage room and insists on changing shoes, washing hands before mulberry and after desiccation. ⑸ is equipped with a special mulberry storage room, which is sterilized with 0.5% available chlorine bleaching powder per age. After sand removal by ⑹, the silkworm room floor was disinfected with 0.5% available chlorine bleach or lime paste. ⑺ diseased silkworms are not allowed to litter or feed poultry. They should be impregnated and disinfected in lime paste and then buried in the soil. ⑻ silkworm sand used as fertilizer must be composted and fully fermented before it can be used. It is forbidden to spread silkworm sand near silkworm rooms and mulberry gardens.

Fourth, disinfection after sericulture. The disinfection after sericulture is commonly known as Huishan disinfection. After cocoon collection, the pathogenic microorganisms such as diseased silkworm carcass, silkworm feces and dead cage rotten cocoon can easily spread to the silkworm room, silkworm equipment and surrounding environment, and become the source of infection of silkworm in the next season. For this reason, the following must be done: ⑴ will first spray and disinfect silkworm rearing and used silkworm utensils with 0.5% available chlorine bleach or 1-2% lime paste, and then wash, dry and store. ⑵ will use old clusters, burn waste, or compost it together with silkworm sand. If some clusters still need to be used, they must be centrally kept after disinfection. ⑶ silkworm room, mulberry storage room, cluster room cleaning and disinfection, completely eliminate diseased silkworm carcass, rotten cocoon, silkworm sand and other residues. The environment around the ⑷ silkworm room should be cleaned.

Fifth, select and raise strong varieties and strengthen feeding and management. There are obvious differences in disease resistance of silkworms. Therefore, the selection and cultivation of strong silkworm varieties to enhance the physique of silkworm is an important link in the prevention and control of silkworm disease.

The disease resistance of big silkworm is stronger than that of young silkworm, but it has weak adaptability to high temperature and humid environment at this time. In big silkworm period, it is necessary to prevent high temperature and muggy heat, strengthen ventilation, put silkworm seats sparsely, and eat good mulberry.

Sixth, control mulberry pests and avoid mutual infection. Mulberry pests can also have diseases such as stiff disease, virus disease, bacterial disease, microparticle disease and so on. Many pathogenic microorganisms can be infected with silkworm and become the source of infection of silkworm disease. When applying pesticide in mulberry garden, it should cooperate closely with sericulture to avoid mulberry leaf pollution, and divide the pesticide into different areas and collect leaves according to the residual effect period of pesticide.

Seventh, diagnose silkworm disease in time and control the spread of the disease. The types of silkworm diseases are different and the disease symptoms are different. In the same case, due to the different onset period, the symptoms are also different. Most of the diseased silkworms were first found in the retarded and weak silkworms. In the diagnosis and examination of silkworm disease, the late sleeping silkworm and weak silkworm should be taken as the key objects to achieve the purpose of timely diagnosis and comprehensive control of silkworm disease.