Control of common diseases of silkworm, Bombyx mori

First, particle disease. Commonly known as flower sausage, it is a devastating infectious disease. 1. Etiology: caused by the spore infection of parasite. The route of transmission: one is embryo transmission, that is, the infected eggs laid by the diseased mother moth are passed to the offspring; the other is ingestion, that is, the silkworm eats the spores of microzoa and causes the disease. two。 Symptoms: population dysplasia, small silkworm body, poor appetite, sleepless silkworms, late rise or poor molting, and sometimes black-brown spots of different sizes on both sides of the ventral surface. When the 5th instar diseased silkworm was torn into the outer skin, the milky white lesion (protuberance) of the silk gland could be seen. He was seriously ill and died without spinning silk. Most of the embryos infected died before 2 or 3 years old, and those infected with 3 years old died at 5 years old. 3. Control: ① seed production farm should strictly carry out microscopic examination of insects and moths in order to produce disease-free silkworm eggs and put an end to embryo transmission. The former silkworm house and silkworm utensils were thoroughly disinfected by ② @ # @ 250mm. During the silkworm period, we should do a good job in disinfection and disease prevention of silkworm, so as to reduce the infection under food. ③ strengthen feeding management, do not collect seedlings, tail ant silkworms, implement high temperature feeding, moths, second sleep to eliminate late dormant silkworms.

Second, white mouth disease. Including midgut purulent disease and emptiness malacia. All instar silkworms can occur, especially in 3-6 high temperature season, which is more likely to cause outbreaks of 5th instar silkworms, which is the most common and serious infectious disease. 1. Etiology: ① cannibalizes the infected mulberry leaves. ② was induced by adverse environmental conditions. Such as high temperature and stuffy heat, poor ventilation, hard leaves and withered leaves, silkworm hunger and other effects, easy to cause disease. The virus nibbled down to the pathogenic amount of the virus fell ill in 4 to 7 days. After 48 hours of infection, the virus was transmitted to healthy silkworms in vitro with the excretion of silkworm feces, resulting in mixed rearing and transmission of silkworms. If a few silkworms are infected at 2-3 years old, a large number of silkworms will be infected at 5-year-old. The silkworm disease broke out in the later stage of the 5th instar when it was infected with the disease at the age of 4 to 5 years old, encountered high temperature and other adverse environment. two。 Symptoms: ① midgut type purulent disease: small nibbling, dull action. Large silkworm body color turned white, silkworm body thin, white soft feces, torn silkworm body, you can see the back of the midgut or the whole midgut is milky wrinkle. ② hollow malacia: the appearance symptom is similar to the midgut type pyomalacia, but the chest of the diseased silkworm is dilated and transparent, like pseudo-ripe phenomenon, discharge thin feces or brown sewage. There is no milky wrinkle in the midgut and no accumulation of mulberry leaves in the intestine, showing yellowish brown and slightly transparent. 3. Prevention and treatment: the silkworm is mainly disinfected to prevent disease and full before eating, and full to prevent heat pot after big sleep, and the disease of white mouth can be controlled. ① should strictly do a good job of disinfection before, during and after sericulture, eliminate diseased silkworms, weak silkworms and late silkworms in time, and prevent mixed rearing infection. ② chooses mulberry to grow young silkworms so that the silkworms can have enough to eat. In dry weather, mulberry leaves should be fed with water to enhance the health of silkworms. ③ strives to be cool and cool in the silkworm room, so that it can be released, released low, released less, and reared separately. ④ will sleep as soon as he has enough to eat, and the silkworm will be released in time.

Third, body cavity type purulence. 1. Etiology: ① is infective under food. The pathogen is a viral virus, which is often infected by silkworms when it is attached to the egg or mulberry leaves. Young silkworms and silkworms have weak disease resistance and are easy to be infected by food. ② trauma infection. After the wound of the silkworm body skin, the virus invaded the silkworm body from the wound and became infected. The morbidity of big silkworm is high because of many opportunities of trauma. ③ was induced by adverse environmental conditions. When the silkworm is infected with the virus, in the wet and heavy environment with great changes in temperature, or eating old and tender mulberry leaves, or over-close breeding, silkworm weakness is more likely to occur. two。 Symptoms: thin silkworm green body, the sleeping silkworm skin is tense and bright, and the silkworm flesh is relaxed and contracted. Big silkworm body color milky white, manic restless, often crawl to the edge of the nest, the link swelling into high section silkworm, the skin is easy to break out of milky white pus and die. The disease was an acute disease and died 4-6 days after infection. 3. Prevention and treatment: ① thoroughly disinfects silkworm houses and silkworm utensils. Diseased silkworms were found to be picked out and thrown into a lime basin in time. ② silkworm body and silkworm pedestal were disinfected with new lime powder before replacing feces of silkworms at each instar, and sprinkled once a day when diseased silkworms were found. ③ silkworms are properly thinned during the period of strong silkworm growth to reduce the scratches of silkworms. Divide the nest carefully and gently to avoid damage to the silkworm body. ④ avoids eating tender mulberry and strengthens the physique of silkworm. Temperature and humidity should be adjusted evenly, not high and low, and do a good job of dehumidification.