Have you ever raised silkworms? Think back to your sericulture experience and answer the following questions in combination with the development of silkworm: (1) What do you think is the origin of silkworm life? Incomplete metamorphosis: Larvae and adult are very similar in morphological structure and living habits, but they are immature in all aspects. Their development goes through three stages: egg, nymph and adult. Such as dragonflies, cockroaches, crickets, locusts and so on. Complete metamorphosis: insects go through four stages: egg, larva, pupa and adult. Completely deformed larvae. There are great differences, such as butterflies, mosquitoes, flies, cabbage butterflies, bees, silkworms and so on. The development process of silkworm is four stages: fertilized egg → larva → pupa → adult, and it is completely metamorphosed. 1 is an adult, 2 is a pupa, 3 is a fertilized egg and 4 is a larva.

(1) Silkworm is a completely metamorphosed insect, and its development process is divided into four stages: egg, larva, pupa and adult. So the silkworm's life begins with three fertilized eggs in the picture.

(2) The development process of locust is: fertilized egg → nymph → adult, which is an incomplete metamorphosis development; The development process of silkworm is four stages: fertilized egg → larva → pupa → adult, which is completely abnormal, so it has a second pupa stage more than locust.

(3) Silkworms develop into larvae from fertilized eggs, feed on mulberry leaves, molt for four times, stop feeding on mulberry leaves, spin cocoons and surround body form cocoons and pupae. From the spring silkworm to the pupa stage, the pupa skin becomes hard, so it is impossible to spin silk. Therefore, the general silkworm raiser will spray a chemical substance on the mulberry leaves for gnawing, which can appropriately increase the accumulation of nutrients in the larval stage. To make sure

(4) Silkworms have the phenomenon of "trapping themselves", which is innate, controlled by genetic material in the body and innate behavior.

So the answer is:

(1)3 fertilized eggs.

(2)2; Pupa; Completely transformed.

(3)4; larva

(4) genetic material.