Technical measures to prevent secondary cocoons of silkworm, Bombyx mori

Raising silkworms and choosing high-yield and high-quality cocoons is the key to high yield and harvest. In the process of silkworm feeding, the benefit is reduced due to many factors that produce cocoons for many times. In order to avoid the occurrence of secondary cocoons, increase the cocoon rate and reduce the secondary cocoon rate is an important link to further increase the economic benefits of sericulturists. The relevant technical points for preventing secondary cocoons are briefly introduced as follows:

1 to strengthen feeding and management

1.1 the young silkworms were reared with plastic film, which not only kept the mulberry leaves fresh, but also promoted the larvae to like to eat, which was beneficial to the larval good mulberry to eat, improve the larval physique and enhance the disease resistance.

1.2 after the ants are collected, feed the leaves in time. When there is irregular sleep, it should be raised in batches. When raising large silkworms, it is appropriate to feed the leaves thinly and frequently so that the larvae are full.

1.3 due to the long-term sericulture in the same place, there are many pathogens accumulated and the spread surface is large, so it is necessary to disinfect thoroughly and do a good job of disinfection. Methods: first clean, then wash and disinfect, spray indoors and outdoors with bleach containing 1% available chlorine.

1.4 the hot and muggy weather is the most harmful to the larvae, so when rearing large silkworms, the doors and windows of the silkworm room should be often open and ventilated, which is beneficial to the growth and development of the larvae.

1.5 if you encounter long-term high temperature and dry weather, always spray cold water on the wall. Give the larvae more water leaves, thin leaves, and feed them frequently to ensure that they are fed with fresh leaves each time.

1.6 if you encounter low temperature and humid weather, the room should be heated and drained, and the window should be opened in time for air exchange. Bombyx mori should be sparse, and silkworm droppings should be removed frequently. Feed mulberry leaves with little moisture.

1.7 in case of muggy weather before rain, open windows for ventilation and feed fresh mulberry leaves. When the rain and wind are strong, it is necessary to close the doors and windows in time, and then open the doors and windows for air after the wind is slightly weaker, so as to ensure a good habitat for the larvae.

2 prevention of secondary cocoons

2.1 double palace cocoons

2.1.9 when the larvae make cocoons, too many mature silkworms are put on the paraphernalia, and more than two mature silkworms are artificially squeezed into double palace cocoons.

2.1.2 harmfulness the silk head of the cocoon is chaotic, the loading rate of silk reeling is low, the silk reeling is difficult, the silk quality is rough, and the quality of this cocoon can only be purchased as a secondary cocoon.

2.1.3 Preventive measures in cooked silkworms, checkered silkworms or plastic folds should be selected to achieve suitable ripe silkworms, 1 cocoon position for 1 mature silkworm, mature silkworms should not be too old, and should be served in time.

2.2 thin skin cocoon

2.2.1 the reason is that the larval stage does not reach the full feeding of good mulberry, and the silk production of the larvae is less. During the cocoon production period, the indoor humidity was high and the temperature was on the high side, so the thin-skinned cocoons were produced when the best spinning time of mature silkworms was missed.

2.2.2 harmfulness due to soft cocoon shell, loose and thin cocoon layer, unable to reel silk or produce less silk.

2.2.3 Preventive measures should be taken to ensure that the larvae are fed with good mulberry to prevent starvation. In the larval stage, we should pay attention to disease prevention, improve the health of larvae, and prevent larvae from carrying disease. The swimming silkworms and mature silkworms on the ground should be picked up and washed with clean water in time to prevent the room temperature from getting too high and the humidity too high.

2.3 Cocoon piercing

2.3.1 the reason is that the cocoon is caused by improper fly control in the larval stage, the cocoon is hot and humid in the cocoon production period, and one or two cocoons are perforated by biting through the cocoon shell.

2.3.2 harmfulness because the cocoon silk is broken, it can not be reeled normally, and the economic benefit of sericulture is affected.

2.3.3 Preventive measures during the larval stage, fly prevention should be done to prevent maggot cocoons; cocoon making rooms should prevent high temperature and humidity, so as to prevent cooked silkworms from biting through the cocoon shell and drilling through the head cocoon.

2.4 contaminated cocoons

2.4.1 the reason is that the mature silkworm is too dense, the feces and urine of the mature silkworm is not removed in time, and the mature silkworm suffers from the disease, which results in pollution inside and outside the cocoon shell and yellow spots on the surface of the cocoon shell.

2.4.2 harmfulness this cocoon produces filament when reeling, the silk quality is poor and the quality is low.

2.4.3 Preventive measures: remove cooked silkworm droppings and paper cushion in time after the formation of medium-ripe cocoon shell, keep indoor temperature and dry; prevent diseases during larval stage, prevent disease on mature silkworm, avoid pollution of cocoon shell after death; gently pick and put cocoon when picking cocoon, prevent pupa in cocoon from being damaged, causing pupa liquid to pollute cocoon shell.

2.5 cocoons printed with firewood

2.5.1 the reason is that the wood-stamped cocoon is produced because the material is too hard and the cooked silkworm is too dense.

2.5.2 harmfulness this cocoon can not be reeled, even if the silk reeling yield is low.

2.5.3 Preventive measures should avoid using hard materials such as wheat and rice straw as harness tools, select checkered or plastic folding cymbals as cocoon harness, improve the excellent cocoon rate, and put mature silkworms according to the standard capacity to keep the mature silkworms from being too dense.

2.6 hairy foot cocoon

2.6.1 the cause is that there are diseases in the larval stage, and the pupa cannot be normalized after cocooning, resulting in disease and dead foot cocoons.

2.6.2 Preventive measures should be taken in a timely manner.

2.6.3 Identification method sampling cocoon shaking heard a crisp sound indicating the end of pupation. You can also use scissors to cut the cocoon and see that the pupa turns yellowish brown, which is the right time for cocoon picking, otherwise it is hairy foot cocoon.

2.7 avoid cocoon mixing

When picking cocoons, the upper cocoons and secondary cocoons should be spread out respectively to improve the quality of cocoons, ensure the high quality and sale of cocoons, and strictly prevent the mixing of cocoons, resulting in bad economic losses.