Ten observations for silkworm disease prevention and control: remember these ten key points when raising silkworms

1. Observe the development of the colony. When the ants are collected, the hatching is uneven, the ant silkworms are uneven in size, with big heads and small tails, spin a lot of silk, and crawl around the rearing seat, indicating a weak constitution. During rearing, touch the silkworm body with your hand or lift the silkworm up; if the silkworm contracts and resists, it is healthy; if it has no reaction, it indicates a weak constitution. In the large silkworm stage, touch the silkworm body flatly with the back of your hand; if it feels cold, it is a healthy silkworm; if it feels damp and hot, it indicates that the constitution is not strong.

2. Observe the posture before and after molting. When a healthy silkworm is about to molt, its head and thorax are raised, and molting is uniform. If it does not enter sleep for a long time, and after entering sleep its head and thorax lie flat and the tail is small; or if half-molting or no molting occurs, these are signs of weak or diseased silkworms.

3. Observe leaf eating. Healthy silkworms have a normal appetite, and very little mulberry leaf remains. If at the next feeding there is a lot of leftover leaf in the silkworm tray, the silkworms move sluggishly, raise their head and thorax, and lie hidden in the rearing seat or among the leftover leaves, it is mostly a sign of weak constitution or disease.

4. Observe silkworm droppings. Healthy silkworm droppings are hexagonal-columnar, black, and hard. If the droppings are thin and soft, irregular in shape, or several pellets joined in a string and stuck to the tail, with sewage exuding, they mostly belong to weak or diseased silkworms.

5. Observe movement. Before feeding leaves, gently blow on the silkworm body with your mouth; if it responds sensitively and raises its head and thorax, it is a healthy silkworm. If it responds slowly, is often motionless, or hides in the rearing seat, or crawls around, it is a weak or diseased silkworm.

6. Observe body color. Healthy silkworms have a clear white body color. Diseased silkworms are mostly dirty and dull, with diseased spots of varying sizes appearing on the whole body or part of the skin, the abdominal legs and tail horn burnt black, the skin loose, wrinkled, or tense and shiny, and the intersegmental membrane losing its elasticity.

7. Observe the pulse. The pulse is the speed of pulsation of the silkworm's dorsal vessel. Under the same conditions, the pulse of diseased silkworms is slower than that of healthy silkworms. Poisoned silkworms or silkworms with flacherie are at first faster than healthy silkworms, and later slower than healthy silkworms, with uneven intervals, until they stop completely.

8. Observe water vomiting. Water vomiting mostly occurs in diseased silkworms; some vomit a large amount of water, some have a swollen thorax and vomit a small amount of water, and some curl their head and thorax and vomit water.

9. Observe diseased spots. Silkworms with spots appearing around the spiracles, on the back, at the junction of head and thorax, or on both sides of the tail are diseased silkworms.

10. Observe blue-headed silkworms and late-sleeping silkworms. Generally, diseased silkworms first appear among the late-developing blue-headed silkworms or late-sleeping silkworms.

When observing signs of disease, these silkworms should be the focus. If the blue-headed silkworms and late-sleeping silkworms show no signs of disease, it indicates that the whole batch of silkworms is relatively healthy; if disease has already been found in this batch of silkworms, the large batch of silkworms should be observed in time, and effective measures should be taken for prevention and control. When a small number of diseased silkworms appear in the colony, the diseased silkworms should be discarded and the silkworm bodies and rearing seats disinfected; if there are many diseased silkworms, they should be isolated and culled in time, and chemical control should be carried out according to the different types of diseased silkworms.