CATDOLL : CATDOLL: What is the most obvious feature of grasshoppers?

1. What is the most obvious characteristic of grasshoppers?

The Chinese grasshopper is an omnivorous insect with a wide range of host plants, including sorghum, wheat, rice, cotton, various weeds, sweet potatoes, sugarcane, cabbage, kale, radish, beans, eggplant, potatoes and other crops, vegetables, and flowers. It often bites leaves into notches or holes, and in severe cases, it eats all the leaves. It is distributed throughout the country, from Heilongjiang in the north to Hainan in the south, and from Sichuan and Yunnan in the west. It is also called grasshopper in northern my country.

2. Locusts can adapt to life in the air and on land. Their morphological and structural characteristics are: Locusts can adapt to life in the air and on land. Their morphological and structural characteristics are:

B.

The reason is very simple: Answer: ① Locusts exchange gases with the outside world through trachea, and the spiracles are a portal for gas to enter and exit, which is suitable for terrestrial life; ② Locusts also have two pairs of wings, the front wings are leathery, narrow and long, and have a protective function, and the hind wings are soft and wide, suitable for flying; ③ There is an exoskeleton on the body surface, which has the function of protection and support and reducing the evaporation of body water. This is the main reason why arthropods adapt to terrestrial life; ④ There is a pair of compound eyes, which plays an important role in the feeding, growth, reproduction and other activities of insects, but for the complex living environment, its vision cannot be considered developed, so ①②③ meet the requirements of the question,

So the answer is: B

3. Do locusts change color? How do they change color?

Locusts are also known as "grasshoppers", "grass moths", "grasshoppers" and "grasshoppers".

Characteristics: Usually green, brown or black, with a large head and short antennae; the pronotum is hard and extends to the left and right like a saddle, and the midthorax and metathorax are fused and cannot move. The feet are well-developed, especially the muscles of the hind legs are strong and powerful, and the exoskeleton is hard, making it an expert in jumping. The tibia also has sharp saw spines, which are effective defensive weapons. The ovipositor does not have obvious protrusions, which is the biggest difference from katydids.

In addition to antennae, the locust's head also has a pair of compound eyes, which are the main visual organs. At the same time, there are three simple eyes that can only sense light. There is a mouthpart under the head, which is the feeding organ of the locust. The locust's mouthparts are composed of an upper lip (1 piece), a pair of upper jaws, a tongue (1 piece), a pair of lower jaws, and a lower lip (1 piece). Its upper jaw is very hard and suitable for chewing, so this type of mouthpart is called a chewing mouthpart.

On both sides of the first segment of the locust's abdomen, there is a pair of half-moon-shaped membranes, which are the locust's auditory organs. The small holes arranged neatly on the left and right sides are the spiracles. From the middle thorax to the eighth segment of the abdomen, each body segment has a pair of spiracles, for a total of 10 pairs. Each spiracles is connected to the trachea inward (see the picture below). In the locust's body, there are tracheae of varying thicknesses that are connected vertically and horizontally. The tracheae branch again and again, and finally connect to each cell through fine branches to perform respiration. Therefore, the spiracles are the gateways for gases to enter and exit the locust's body.

Diet: Likes to eat thick leaves, such as sweet potato, water spinach, etc.

Metamorphosis: Incomplete metamorphosis.

Kingdom Animalia, Phylum Arthropoda, Class Insecta.

After mating, the female locust inserts the ovipositor into the soil 10 cm deep and lays about 50 eggs.

When laying eggs, the female insect secretes a white substance to form a cylindrical plug, and then lays the eggs.

The development process of locusts is relatively complicated (see the picture below). Its life begins with a fertilized egg. The larvae that have just hatched from the eggs have no wings and can jump, and are called jumping nymphs. The morphology and living habits of jumping nymphs are similar to those of adults, but they are smaller in body and their reproductive organs are not fully developed, so they are also called nymphs. Nymphs gradually grow up, and when they are restricted by the exoskeleton and cannot grow any further, they shed their original exoskeleton, which is called molting. Nymphs molt five times in their lifetime. From egg hatching to the first molting, it is the first instar, and each subsequent molting increases the instar by one. After the third instar, the wing buds are prominent. After the fifth instar, they become flying adults. It can be seen that the individual development process of locusts goes through three stages: egg, nymph, and adult. Such a development process is called incomplete metamorphosis. The entire individual development history of an insect from a fertilized egg to an adult, and the ability to produce offspring, is called a generation. In some areas of my country, locusts can produce two generations of summer locusts and autumn locusts in one year, so there are two generations.

This is an egg that has developed for 19 days; at around 24°C, the eggs of locusts can hatch in about 21 days. The hatched nymphs crawl out of the soil. At this time, their appearance is very similar to that of adults, but they have no wings and their body color is lighter. The larvae look more like adults in the first one or two instars, but their heads and bodies are not proportional. In the third instar, wing buds grow, and this is the fourth instar. The wing buds are already very obvious. In the fifth instar, the nymphs are already mature and will crawl onto the plants after feeding for a few days, with their bodies hanging down. After waiting for a period of time, the adults will emerge.

Morphology and living habits: Both adults and larvae of locusts can chew the stems and leaves of plants with their well-developed chewing mouthparts.

Locusts are good at flying and jumping. The pair of antennae on their heads are organs that combine smell and touch. Their chewing mouthparts have a pair of large and well-developed jaws with teeth, which can bite off the stems and leaves of plants. They have strong hind legs, and mainly rely on their hind legs when jumping. When locusts fly, the hind wings play a major role, and when they are stationary, the front wings cover the hind wings for protection. The female insect has a strong "ovipositor" at the end of its abdomen, which can be inserted into the soil to lay eggs. Locusts lay eggs mostly on moist riverbanks, lakesides, foothills, and ridges. Every 30 to 60 eggs form a block. The immature locusts that hatch from the eggs are called "nymphs", and they need to shed their skin five times before they can develop into adults. After the rain, the sky clears up, which can promote the hatching of a large number of eggs. Locusts also have an amazing ability to fly, and can fly continuously for 1 to 3 days. When locusts fly by, the sound of the locusts flapping their wings is amazingly loud, like the howling of a storm in the ocean.

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The hind leg segments of adults have a row of nipple-like protrusions that are equivalent to springs, and the base of the radial veins of the forewings has thick veins that are equivalent to string instruments. When the two rub against each other, the vibration area of ​​the wings can produce sound, which is their sound organ. The locust's auditory organ is also very special, located on the side of the first segment of the abdomen.

locust

Source: Yahoo Knowledge+

Locusts are herbivorous insects. The larvae that hatch from eggs have a similar body shape to the adults. They often hide in the grass and feed on the stems and leaves of plants.

The green body color of the larvae is a natural protective color. It can hide itself in green plants and make it difficult for enemies to find it. However, when it is active during the day, it is often caught and killed by birds. Therefore, the wingless larvae rarely move in the grass and live alone in inconspicuous places. When the larvae encounter danger, they often jump suddenly with their hind legs and jump into the deep grass.

Adult locusts appearing in the grassland

The larvae of herbivorous locusts have a protective green body color; but when they reach adulthood, they must go to the ground where vegetation is sparse to lay eggs and mate, so their body color after emerging from their pupae usually turns brown, which is very similar to the ground.

In addition, in autumn, the body color of the adult insect will also change to a color similar to dead grass.

Even herbivorous insects can change their body color depending on their living habitat and growth stage.

Mating and egg laying of locusts

Locusts that use vision to find females

Locusts that live on open grasslands have very developed eyes.

If you throw a piece of wood on the grass, a nearby male locust will suddenly jump onto the wood; this is because it mistakes the wood for a female locust and wants to mate with it. This shows that adult locusts can use their eyes to find and distinguish the opposite sex.

Adult locusts often appear in the grass and gather in groups in open spaces with sparse green grass and a wide view to mate with their mates.

The mating of locusts

It is not easy for locusts to find mates on the vast plains.

Male insects also use their eyes to find mates, but in order to find a mating partner accurately, they must first confirm the partner's body color, head and antennae shape, etc. at an early stage.

When the male insect is sure that it is a female of the same species, it will ride on the back of the female insect and maintain this posture. They will live together until the mating season comes.

The purpose of adopting this mate-finding method is to ensure intraspecific mating and prevent hybridization.

Locusts that call to females by chirping

Among the small locusts that hide in the grass, there are also some that call females by chirping during the day. These locusts use their hind legs to rub the rasp of their front wings to make the sound. This sound can not only indicate its sphere of influence and call locusts, but also has the meaning of intimidating other locusts. The chirping sound varies depending on the species.

When female insects of the same species hear the call of a male insect, they will respond to the call and go to the male insect's territories, and then approach each other to mate.

Grasshoppers that lay eggs in the soil and on plant stems

After mating, the female locust inserts the ovipositor into the ground to lay eggs; locusts without ovipositors will also insert their abdomen into the soil and lay eggs wrapped in foam. Some species also insert the ovipositor into grass stems or tree trunks and lay eggs inside.

Orthoptera insects mate only once a year, usually between summer and autumn, and then lay eggs in the soil or in the stems of plants and overwinter with eggs. But there are also some species that survive the winter as larvae and adults.

Migrating locusts

Locusts usually live in sparse numbers on vast grasslands. However, in places with suitable climates, lush vegetation, and few natural enemies, their numbers will continue to increase. As a result, the number of locusts and the amount of food will gradually become unbalanced, and locusts with black bodies will gradually emerge. The black locusts gradually gather together, emerge in groups, and become locusts with longer wings.

In order to find places with abundant food, these locusts will fly out together and migrate in groups. In places such as China and Africa, you can often see a large group of locusts suddenly flying over, covering the sky and changing the color of the earth. When locusts pass through, they often cause large-scale crop losses and disasters.

When locusts live in scattered habitats, their body color is the same green as the surrounding plants, blending in with the environment. When their numbers increase, locusts of the same species turn black and produce adults with long wings. This change in order to move and find new food and shelter is called migratory.

Locust with elongated wings

The long-winged black locust is a deformed locust that results from overbreeding locusts in a small living environment.

When the number of locusts per unit area increases, they will fight with each other. At this time, the smell of the same kind will stimulate the locust's brain, causing the hormones in the body to take effect and change the structure of the body.

Therefore, after molting, the locust's body color turns black and it emerges as a migratory locust with long wings.