The key to rearing silkworm in summer

At present, in the rural areas of our country, there are many sericulturists, because from the development situation of our country at the present stage, the demand for silk is still quite large, not only in our country, but also in foreign countries. But in the process of sericulture, what we should pay attention to is different from season to season.

The key to rearing silkworm in summer

Fang Shiyong, Zhongling team of Tuoshe Village, Shangdu Township, Pingnan County, is an expert in sericulture. He has a mulberry garden of two and a half mu and has had a bumper harvest of summer cocoons for five years in a row. In 1987, he raised 28.5 silkworms, producing 726.75 kilograms of fresh cocoons and earning a total income of 4212.70 yuan. The average mulberry yield per mu will be worth 1685.08 yuan. His main experience is:

1. Flexible measures for fruit picking to control adverse climate

The hot June is the rainy season and drying period in southeastern Guangxi, with heavy wet rain, high temperature, sometimes sudden sunshine and sudden rain, and sudden change of air temperature. therefore, it is necessary to strengthen the ventilation, cooling and dehumidification during the silkworm period. The method is: the ① hot and muggy weather is the most harmful to the silkworms that will sleep, sleep and rise, so when rearing large silkworms, the doors and windows of the silkworm room should be often open. In a windless day, the door of the silkworm room is blown by an electric fan. In the hot and dry weather of ②, an Arbor is built outdoors and the walls are sprayed with well water. Give silkworms more water leaves, thin leaves feed frequently, and eat fresh leaves for every meal. In case of low temperature and wet weather, ③ burns straw for heating and dehumidification, about 10 minutes each time, and then opens the window in time for air exchange. The silkworm seat should be sparse, and the shit should be cleaned up frequently. Sprinkle straw ash before picking leaves to absorb moisture. ④ thunderstorm weather, muggy before the rain, must open the window ventilation, and feed to the fresh leaves, when the thunderstorm comes, if the wind is strong, to close the doors and windows in time, when the wind is weaker, then open the doors and windows for air.

Second, strict disinfection and disease prevention

During the summer silkworm period, each batch of silkworms has a short cycle, more pathogen accumulation and large spread surface, so each batch of silkworms should be disinfected in time. The method is to sweep, wash and then disinfect, and spray the bleach powder for indoor and outdoor use into a concentration solution containing 1% available chlorine.

III. Strengthen feeding and management

① small silkworm is cultivated with plastic film, which can keep the mulberry leaves fresh and make the silkworm full.

② summer temperature is high, ant collection should be carried out at 07:00, finished within an hour, and timely leaf feeding. If there is irregular sleep, it should be raised in batches. In order to raise large silkworms well, they should be fed thin and fed sparsely.

The rearing method of big silkworm

1. Feeding and management: the 4th and 5th instar silkworm is called big silkworm, the optimum temperature is 25 ℃, and the difference between dry and wet is 3 ℃. Usually after the fifth instar is fed to the second leaf, the silkworms are moved to the ground. Before the silkworm goes to the ground, first clean and wash the ground, and disinfect it with bleach powder. After drying, spread a layer of lime powder on the ground, and then move the silkworm to the ground. Raise large silkworms to achieve good ventilation, strengthen disinfection, use lime powder to disinfect silkworm seats once a day (before mulberry), do not pick yellow leaves, mud leaves, soot leaves, insect bites leaves.

2, maturity characteristics: large silkworm consumption, to achieve good mulberry satiety, a piece of silkworm eggs with 500 kg of leaves, five-year-old silkworms begin to mature after 6-7 days, the characteristics of silkworm maturity is to stop eating mulberry, discharge a large amount of green soft dung, chest transparent, the body is slightly soft and shortened, showing waxen; the head swings around, and this is the appropriate time for the upper cluster.

3. Upper cluster method: the upper cluster method of square clusters is to select 4 or 5 square clusters to overlap horizontally alternately, then spread the cooked silkworms evenly on the clusters, and hang the cluster hooks after the silkworms crawl. It is necessary to maintain good ventilation during the cluster period. Generally, cocoons can be collected and sold after six days in spring silkworms and 4 or 5 days after clustering in summer and autumn.

Growth process of Silkworm, Bombyx mori

The silkworm is an abnormal insect, the most common is the silkworm, which originated in China. It has gone through several stages such as eggs, ants, mature silkworms, cocoons and moths for more than 50 days. The silkworm moths reproduce after mating and die after laying eggs.

1. Bombyx mori eggs: the eggs look like fine sesame seeds, about 1 mm wide and 0.5 mm thick. A female moth can lay 400 eggs, which is light yellow or yellow when it is first laid. It changes to light red bean or red bean color after 1 to 2 days, and then to grayish green or purple after 3 to 4 days. The outer layer is a hard egg shell, and inside is yolk and serosa. The embryos in the fertilized eggs continue to ingest nutrients during development and gradually develop into ant silkworms, which crawl out of the eggshell and turn white or yellowish after the eggshell is empty.

2. Ant silkworm: when the silkworm hatches from silkworm eggs, its body is brown or black, very small and hairy, and looks a bit like an ant, so it is called ant silkworm. The ant silkworm is about 2 mm long and 0.5 mm wide. After climbing out of its eggshell, it will eat mulberry leaves after 2-3 hours.

3. Mature silkworm: at the end of the fifth instar, the baby silkworm gradually shows the characteristics of maturity. At first, the excreted feces change from hard to soft, from dark green to leaf green, loss of appetite, decrease of mulberry intake, emptiness of the front digestive tube, transparent shape of the chest, and then completely stop eating, body drive shortens, abdomen also tends to be transparent, silkworm head and chest raised, mouth spitting silk wisps around, swinging up and down looking for cocoon sites, such silkworms are called mature silkworms.

4. Cocoons: when cooked silkworms are placed in special containers or pots, the silkworms spin cocoons. The cocoons are white, yellow, light green, flesh red and other colors, with a length of about 3 to 4 cm, a diameter of 1.7 to 2.1 cm, a white surface with irregular wrinkles, and attached silk in a fluffy shape. The silk grain on the inner wall of the cocoon is very regular, light and tough, not easy to tear, unfeathered cocoon. There is a yellowish-brown silkworm pupa and light brown, wrinkled silkworm skin taken off before pupa.

5. Silkworm moth: the silkworm moth is shaped like a butterfly and is covered with white scales, but because the two pairs of wings are small, they have lost the ability to fly. Generally, after mating for 3 to 4 hours, the female moth can lay fertilized eggs, and the male will die after mating. The female moth can lay about 500 eggs in about one night, and then will die slowly.

Feeding and management techniques of silkworm

1. Do a good job in invigorating and promoting youth

The day before getting silkworm eggs, the co-rearing room should be heated to 38 ℃, and the temperature difference between dry and wet should be 2 ℃ ~ 3 ℃. Immediately after the silkworm eggs were collected, they were spread evenly on the silkworm pedestal paper, and the room temperature was raised to 43 ℃, and the temperature difference between dry and wet was 1 ℃ ~ 2 ℃. The silkworm room heated by coal stove should pay attention to do a good job of ventilation. The silkworm room should be strictly protected from light to make the embryo develop neatly. If the silkworm eggs turn green, the ants can be collected by photosensitivity on the second morning, otherwise it is appropriate to collect ants in the early morning of the third day.

2. Timely ant collection

The time of collecting ants is too early, and some silkworms do not have an appetite when collecting ants, resulting in silkworms eating mulberry differently. If the ants are collected along with the collection, it will cause the underdevelopment of silkworms. The most suitable time for collecting ants should be 2-3 hours after ovalization, and most of the ant silkworms already have an appetite and begin to wander and look for food. In the late autumn, the silkworms collect the ants at 8: 9 a.m. and try to finish by 10:00. If unhatched silkworm eggs are found among the collected ants, they should continue to be protected in the dark and be photosensitive to collect ants the next day.

3. Control density

If the silkworm seat is dense and uneven, it will lead to uneven development of silkworms. Therefore, every time before giving mulberry, the seats should be expanded and evenly seated, requiring that the young silkworms should not touch the silkworms and the big silkworms should not overlap.

4. Rational use of leaves

In order to promote the development of young silkworms, it is necessary to collect leaves and feed them according to the standard of leaves before each instar, so as to avoid using old and tender mulberry leaves. In addition, give mulberry a uniform thickness.

5. Timely change the position of silkworm foil

The silkworms in different positions in the same silkworm room are affected differently by temperature. For example, the temperature above the silkworm shelf and near the fire source is on the high side, the silkworm develops fast, on the contrary, the temperature is on the low side, and the silkworm develops slowly. Therefore, attention should be paid to changing the position of silkworm foil frequently. The period of young silkworms is changed at least once a day.

In the process of sericulture, breeders should adjust their breeding methods and strategies according to the changes of seasons, so if they want to raise high-yield silkworms and high-quality silk, they must fully understand the living habits of silkworms.