What to Do If Silkworms Don't Spin Cocoons? Causes and Solutions

I. Main Causes

1. Pathological factors. For example, with pébrine or flacherie, infection and onset before mounting for spinning destroys the secretory function of the silkworm's silk glands; or the pathogen produces large amounts of toxic metabolites in the silkworm's body, paralyzing the silkworm's nerves so it cannot spin silk or form a cocoon.

2. Physiological factors. Abnormal middle silk glands, mainly caused by excessively high rearing temperatures, overly tender leaves, disordered secretory glands, etc., leading to abnormal silk glands and inability to spin. Next is abnormal anterior silk glands, mainly caused by exposure to large amounts of coal gas, fishy odors, alcohol and other harmful gases during rearing, causing spinning impairment.

3. Trace pesticide poisoning. During rearing or mounting for spinning, silkworms ingest or come into contact with trace amounts of pesticides, causing disordered endocrine glands in the silkworm's body and inability to spin.

4. Improper mounting for spinning. This can rupture the silkworm's silk glands, or temperatures that are too low can cause the silkworm to stop spinning for a long time; mounting too densely leaves silkworms unable to find a place to form cocoons, or the mounting frames are not dry, an improper mounting environment, etc., all easily lead to failure to spin silk and form cocoons.

II. Prevention and Control Methods

1. Prevent silkworm diseases and strengthen management. Strict disinfection is required to eliminate pathogens and cut off transmission routes, and disinfection of the rearing room, rearing tools and the area around the rearing room must be done well. Spray disinfection can be carried out with bleaching powder solution containing 1% available chlorine or the clear supernatant of 1%-2% fresh limewater; strengthen feeding management to enhance the silkworm's resistance. Select silkworm varieties with strong disease resistance to avoid the effects of hot, stuffy summer and autumn weather on the rearing house, maintain suitable temperature and humidity in the rearing room, keep the air fresh, and keep the rearing bed clean; during the grown-silkworm stage, feed chloramphenicol as a supplement 1-2 times per instar, with each milliliter containing 500 units of chloramphenicol.

2. Strictly prevent trace pesticide poisoning. Prevent feeding mulberry leaves contaminated by pesticides; prevent the rearing room, rearing tools and @#@250@#@ supplies from being contaminated by pesticides. Ensure that pesticides are not stored in the rearing room, pesticides are not placed in rearing tools, and sericulture supplies do not come into contact with pesticides.

3. Mounting for spinning must be done carefully. When mounting for spinning, achieve the "three uniformities" and "three dryness". The three uniformities mean: mature silkworms have a uniform degree of maturity, with none under-matured; mounting density is uniform, with none too dense; and mounting maturity is uniform, with none over-mature. The three dryness means the mounting room, mounting frames and tools, and the environment are dry.