The silkworm's life passes through four periods: egg, larva, pupae and adult, which is completely metamorphosed.
Equipment: scissors, brushes and some other silkworm utensils, silkworm eggs, mulberry leaves, magnifying glass.
method:
The eggs are oblate oval in shape, about 1.3 mm long and pale yellow.
In the warm season of late spring, indoor ovulation at about 26 °C with a difference of 3 to 4 degrees Celsius of dry humidity. Indoor shading, the silkworm eggs are placed on white paper, and the next morning the light is used to make the light, and the small silkworm (also known as the ant silkworm) quickly hatches.
During the incubation process, the silkworm eggs gradually change from yellowish yellow to yellowish brown and finally purple. The newly hatched silkworms are black, thin and small, with fine hairs.
First- and second-year silkworms are fed chopped, fresh and tender mulberry leaves. Use a brush or feather to move the silkworm when changing mulberry leaves. Pay attention to maintaining the indoor temperature and humidity (the temperature is 26C to 26.5C, the difference between dry and wet is 3 to 4 degrees). After the third age, the body of the silkworm grows up, to change the large box feeding, mulberry leaves do not have to use all young leaves, give mulberry 3 to 5 times a day. At the fifth age, the silkworm's body is shiny, translucent, and begins to spit silk. At this time, they can be placed on the straw handle as a cocoon.
From the ant silkworm to the fifth-year-old silkworm, a total of four peels. With each peel, the silkworm grows a little longer. When peeling, the silkworm does not eat or move, and the head is raised.
Observe three or four-year-old silkworms. Its body is about an inch long, gray-white, divided into three parts: the chest and abdomen.
(1) The head is very small, has a mouth organ that is good at chewing mulberry leaves, has a pair of antennae on the head, and has six protruding single eyes on each side of the head.
(2) Chest and abdomen The three rings behind the head are the chest, and there are three pairs of pectoral feet. The ten links behind the chest are the abdomen, with a pair of gastropods in the sixth to eighth sections, a pair of tail feet in the tenth section, and a tail horn on the back of the eighth section. There are nine pairs of valves symbiotically on both sides of the chest and abdomen, which are the breathing portals of silkworms.
Observe the silkworm pupae Take the cocoon that has been cocooned for ten days, cut open the cocoon shell, and observe the pupae. The pupae are brown, spindle-shaped, and divided into three parts: head, chest and abdomen. The head has antennae; The chest has three pairs of feet and a pair of wing buds; Ventral segment.
Adult moths lay eggs After more than ten days, the pupa changes into moths, breaks out of the cocoon, lays eggs after mating, and dies after giving birth.
Figure 5-1
The female silkworm moth was observed to have an enlarged abdomen and a comb-toothed antennae gray. The male has a slender abdomen and black feathers at the antennae. Both female and male moths have wings on them.
Through breeding and observation, we can understand the changes in the four stages of silkworm life.
It is suggested that the four insect states of the silkworm's lifetime can be made into specimens for easy observation. Eggs can be dried and stored, larvae are dried by blowing and drying, pupae are soaked with 5% formalin liquid, and moths can be made into specimens by air-drying on the spread wing plate.