Common symptoms of silkworm poisoning and prevention methods

Pesticide poisoning: 1. The pesticides that commonly cause silkworm poisoning fall into several major categories, including organophosphates, organonitrogens, pyrethroids and botanical insecticides. Various pesticides enter the silkworm body through contamination of mulberry leaves, rearing rooms and rearing tools, and the air, and cause poisoning when the silkworms eat them, breathe them in through the spiracles, or come into contact with them.

2. After pesticides enter the silkworm body, three effects may occur: activation, accumulation and detoxification. Most pesticides can accumulate or become activated and cause silkworm poisoning. The common symptom of poisoning by all kinds of pesticides is a sudden stop in feeding on mulberry leaves. Also, because the chemical drugs differ in composition and structure and have different properties, different special symptoms appear, which can serve as a basis for diagnosis. To determine which drug caused the poisoning, one should rely on the body color, posture, behavior, fluid discharge, spasms and corpse state of the poisoned silkworms.

3. Prevention of pesticide poisoning: mainly prevent pesticides from contaminating mulberry leaves, and prevent pesticides from contaminating rearing rooms, rearing tools, the air, and the clothing, hands and feet of the rearers. In addition, attention should be paid to the residual effect period of pesticides: the residual effect period for field application may have passed, but the residual effect period for silkworms may not have passed yet. Because silkworms are raised at home, their resistance is weaker than that of wild insects, and silkworms are very sensitive to concentrations and doses that cannot kill wild insects, so special attention should be paid.

Factory exhaust gas poisoning: Waste gas discharged by factories contaminates mulberry leaves, and silkworms are poisoned after eating the mulberry leaves. The waste gases that cause silkworm poisoning are mainly hf and so2. Silkworms poisoned by waste gas mainly have poor appetite, uneven development, and prolonged instar duration. During the large silkworm stage, the intersegmental areas of poisoned silkworms bulge and have black ring-shaped band spots. The skin breaks easily but the blood is transparent, and microscopic examination shows no pathogens.

Prevention methods: 1. Plant tall shelterbelt tree strips between factories and mulberry fields, such as glossy privet, Chinese scholar tree and Chinese parasol tree, to reduce the harm of waste gas to mulberry trees; 2. Strengthen monitoring of the fluoride content in mulberry leaves; 3. Rear silkworm varieties with strong fluoride resistance; 4. For mulberry leaves near industrial waste gas pollution sources, washing with water or spraying lime slurry can detoxify them and reduce the harm; 5. After silkworms are poisoned, fresh mulberry leaves should be replaced immediately.

Coal gas poisoning: It occurs mostly during the incubation stage or the young silkworm stage, especially during co-rearing of young silkworms, because coal or charcoal is used directly to raise the temperature in the rearing room, and incomplete combustion or certain toxic substances contained in the coal produce harmful gases, which enter the body through the respiration of the silkworms and cause poisoning.

Prevention mainly consists of choosing suitable heating materials, paying attention to heating methods, and changing the air more often, which can avoid it.