CATDOLL : CATDOLL: The appearance of locust

Locusts have well-developed hind legs, and can use them to jump distances several dozen times longer than their bodies. They are incompletely metamorphosed insects, and their larvae and adults are similar, with the only difference being the presence or absence of wings. The hind wings are translucent. The wings of some species of locusts have degenerated and become smaller, and some species, such as the diamond locust, have lost the ability to fly.

The body color is green or brown, regardless of the species; it is a protective color for the living environment. Locusts have large mouths and well-developed jaws, and feed on plant leaves. Locusts like to eat reeds, barnyard grass, white grass, sedge and wormwood, shrimp grass and sea salicornia. Some locust species are omnivorous and also eat dead insects, even the dead bodies of their own kind.

Male insects of some species make sounds to attract females, but they do so by rubbing their wings and hind legs together, unlike crickets, which use the sound organs in their front wings to make sounds.

Additional information:

Locusts are insects of the family Acrididae and order Orthoptera. There are more than 10,000 species in the world. They are distributed in tropical and temperate grasslands and deserts around the world.

Its common names basically include grasshopper, short-horned grasshopper, grasshopper, locust and so on. However, because locusts and katydids look similar, people in different regions often have various different common names for these two insects. For example, "locusts are called grasshoppers and katydids are called grasshoppers", or "locusts are called short-horned grasshoppers and katydids are called long-horned grasshoppers", and "solitary locusts are called grasshoppers or grasshoppers, and gregarious locusts are called locusts or migratory locusts", etc.

In biological classification, the word "grasshopper" can refer to locusts in the families Rhomboidae and Brachyhornedae; the family Rhomboidae is also called "grasshopper", while the family Brachyhornedae is also called "hopper". The origin of locusts, as well as the extinction of some of its species (some of which can be up to 15 cm long), remains unclear.

Reference: Baidu Encyclopedia Locust

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 mesothorax and metathorax are fused and cannot move. The legs are strong, 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. Diet: Likes to eat thick leaves, such as sweet potatoes and water spinach. Metamorphosis: Incomplete metamorphosis.

locust

Observation of locust appearance

Females are larger (40-50mm) and males are smaller (30-40mm). The body is divided into three parts: head, thorax and abdomen.

(1) Head

It is oval in shape, with the exoskeleton fused into a skull. The top of the skull is a blunt-round top of the head, the front is a slightly square forehead, the bottom of the forehead is a horizontal rectangular lip base, and the sides of the forehead are cheeks.

There is a pair of oval, brown compound eyes located on both sides of the head. If you observe the surface of the compound eyes with a magnifying glass, you can see that it is composed of many hexagonal eyes in a honeycomb structure.

There are three light yellow simple eyes, one located in the middle of the forehead, and the other two are located above the inner sides of the two compound eyes.

Antennae: 1 pair, evolved from the 2nd pair of appendages (1st and 3rd pairs of appendages degenerate). Located in front of the inner side of the compound eyes; slender and filamentous, composed of stalk, pedicel and flagellum, which is divided into many subsegments.

The mouthparts are of the chewing type, consisting of three pairs of appendages on the head, the upper lip, and the tongue (General Zoology, page 269).

① Upper lip: one piece, connected to the base of the lip, covering the front of the mouthparts;

② Upper jaw: 1 pair (maxilla), evolved from the 4th pair of appendages, located below the cheeks. Insert a dissecting needle along the subcheek suture to separate the sutures and remove the upper jaw. The upper jaw has incisor and molar parts, which are strong and hard, brown in color, and asymmetrical.

③ Mandibles: 1 pair (maxillae), evolved from the 5th pair of appendages, located behind the upper jaw. Use tweezers to pull off the base, and you can see that there is an axis segment at the base, a stem segment in the middle, a petal-shaped outer maxillary lobe on the outside and an inner maxillary lobe with sharp teeth on the inside. There is a 5-segment lower (small) maxillary palp on the small negative maxillary palp segment next to it;

④Lower lip: 1 pair, evolved from the 6th pair of appendages, fused into one piece on the left and right, located behind the lower jaw, with a crescent-shaped posterior chin at its base, connected to a one-piece anterior chin (chin) in front, with a pair of 3-sectioned lower labial whiskers on both sides, and a pair of lateral labial tongues at the front edge of the anterior chin;

⑤ Tongue: 1, located in the center of the mouth, oval in shape, with a small stalk at the base; there are several chitinous teeth on the surface of the tongue.

(2) Chest

It is connected to the head by a slightly contracted membranous neck and consists of three segments: the prothorax, the mesothorax and the metathorax.

Each thoracic segment of the exoskeleton is composed of four bone plates, namely the dorsal plate on the back, the side plates on both sides, and the ventral plate on the ventral side.

① Back Plate: The pronotum is well developed, saddle-shaped, and extends to the sides and rear; the mesothorax and metanothorax are often covered by the rear edge of the pronotum, square, and divided into several small bone plates;

② Side plate: The anterior chest plate is located at the front end below the dorsal plate and degenerates into a small triangular bone plate; the middle and posterior chest plates are well developed and divided into the anterior and posterior plates by the lateral groove;

③ The pronotum is rectangular, with a horizontal arc and a hook-shaped protrusion in the center; the middle and metanotum are combined into one piece, divided into several bone pieces.

Legs: Each thoracic segment has a pair of segmented legs, consisting of the coxa, trochanter, femur, tibia, tarsus and pretarsus. The tarsus is divided into three sections, of which the first section is longer, forming three pseudo-segments; the pretarsus includes a pair of claws and a middle pad between the claws. The femur of the hind leg is thick and suitable for jumping, called jumping legs; the front and middle legs are both walking legs.

There is a pair of leathery, narrow and long compound wings (forewings) on the dorsal side of the wing midthorax; there is a pair of fan-shaped membranous wings (hindwings) on the metathorax, with obvious wing veins, which are folded and hidden under the compound wings when resting. There is a pair of spiracles on the front edge of the side plates of the midthorax and metathorax.

(3) Abdomen

It consists of 11 segments.

Each abdominal segment of the exoskeleton has only a dorsal plate and a ventral plate, and the side plates have degenerated into lateral membranes connecting the dorsal and ventral plates. The first abdominal segment is closely connected to the metathorax and cannot move; the dorsal plates of the ninth and tenth abdominal segments are shortened and fused, with a shallow groove in between; the dorsal plate of the eleventh segment is triangular, covering the anus, called the supra-anal plate, with an anal lateral plate on each side, which is the ventral plate of the eleventh segment; there is a tail on each side of the rear edge of the tenth segment, which is the appendage of the eleventh segment. The number of ventral plates of the cotton locust is different between males and females. The ninth and tenth segments of the female insect do not have ventral plates, and the rear end of the ventral plate of the eighth segment extends into a pointed ovipositor; the ventral plates of the ninth and tenth segments of the male insect are fused, and the top is pointed and tilted to form a reproductive lower plate.

The external genitalia of female insects is an ovipositor, and that of male insects is a mating organ.

① The ovipositor consists of a pair of dorsal lobes and a pair of ventral lobes, located at the end of the abdomen;

② The copulatory organ is a pair of hooked penises, which can be seen by pressing the lower reproductive plate downwards.

The auditory organ is a pair of oval eardrums located on both sides of the first abdominal segment.

There are 10 pairs of spiracles, 2 pairs on the thorax, located at the front edge of the middle and rear thoracic plates; 8 pairs on the abdomen, located in front of the lower edge of the dorsal plates of the 1st to 8th abdominal segments. A magnifying glass can be used to observe the opening and closing of the spiracles when the cotton locust breathes.

Reproduction and development of locusts

Adults have a pair of well-developed mandibles. They mainly eat grass, especially the stems and leaves of grass plants, such as rice, wheat, sorghum, corn and bamboo. Places with dense grass weeds and vast wastelands are ideal habitats for locusts. Wherever locusts sweep, grass plants are eaten up, and almost everything they can bite is not spared. Swarms of locusts can turn green land into wasteland. Locusts are good at flying and jumping. The pair of antennae on their heads are organs that combine smell and touch. Its chewing mouthparts have a pair of well-developed mandibles with teeth, which can bite off the stems and leaves of plants. It has strong hind legs and mainly relies on its hind legs when jumping. When locusts fly, the hind wings play a major role. 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 river banks, lake shores, foothills and ridges. Every 30 to 60 eggs form a group. The immature locusts that hatch from eggs are called "nymphs" and 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 amazing flying ability and can fly continuously for 1 to 3 days. When locusts fly by, the sound of the locusts flapping their wings is amazing, like the howling of a storm in the ocean.

The life of a locust 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 grow up gradually, 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 adults that can fly. 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.

People have long noticed that severe locust plagues are often accompanied by severe droughts. There are records of "extreme droughts and locusts" in ancient Chinese books. Several major locust plagues in Africa in recent years have also been associated with severe droughts in the area. The main reason for this phenomenon is that locusts are insects that like warm and dry environments, and arid environments have many benefits for their reproduction, growth, development and survival. Because locusts lay their eggs in the soil, the soil is relatively solid and the water content is 10% to 20% which is most suitable for them to lay eggs.

Drought causes locusts to reproduce in large numbers and grow rapidly, causing disasters for two reasons. On the one hand, in drought years, due to the drop in water levels, the soil becomes more solid, the water content is reduced, and the ground vegetation is sparse, so the number of locust eggs increases greatly. In some cases, 4,000 to 5,000 egg masses are laid per square meter of soil, each egg mass contains 50 to 80 eggs, that is, 200,000 to 400,000 eggs per square meter. At the same time, in drought years, the surface of rivers and lakes shrinks, and low-lying areas are exposed, which also provides more suitable places for locusts to lay eggs. On the other hand, plants grown in arid environments have lower water content, and locusts feed on them, grow faster, and have higher fertility.

On the contrary, rainy and humid environments have many adverse effects on locust reproduction. The high water content of plants that locusts feed on will delay their growth and reduce their reproductive capacity. Rainy and humid environments can also cause locust diseases to spread, and rain and snow can directly kill locust eggs. In addition, the increase in natural enemies such as frogs will also increase the mortality rate of locusts.

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.

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. In the first one or two instars, the larvae look more like adults, but their heads and bodies are disproportionate. In the third instar, wing buds grow, and in 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 and waiting for a while before the adults 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.

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.

Prevention and treatment methods

1. Agricultural prevention and control

⑴ Develop water conservancy to ensure that there is no disaster from drought or flood.

⑵ Reclaim large areas of wasteland and plant crops to change the habitat of locusts and reduce the area of ​​the outbreak base.

⑶ Plant trees and afforestation to change the microclimate in locust areas and reduce the number of suitable places for locusts to lay eggs and reproduce.

⑷ Improve farming and cultivation techniques to control locust eggs, adapt to local conditions, change crop layout, and reduce locust damage.

⒉ Biological control

⑴ In locust-infested areas, use highly effective and low-toxic agricultural and biological pesticides to protect the predatory natural enemies in the locust areas.

⑵ Apply microsporidia over a large area.

Things to note when raising locusts

1. Selection and identification of locust breeding sources

Methods for determining locust species include: (1) Consulting locust classification experts; (2) Consulting locust retrieval tables or atlases; (3) Consulting experienced locust breeders; (4) Sending locust species to customers for identification and review, etc.

Common types of farmed locusts include: East Asian migratory locust, cotton locust, Chinese rice locust, Chinese grasshopper, etc. These varieties have their own advantages and disadvantages. It is necessary to comprehensively consider factors such as their growth cycle, generation, taste, food, size, and the variety required by the customer, and select the breeding variety in combination with the local climate, food source, etc.

2. Construction of locust breeding shed

The area of ​​the shed depends on the number of locusts, and generally about 300 adults can be raised per square meter. To breed migratory locusts under natural conditions, the construction of the shed must be completed before the end of April, because the eggs of northern locusts can usually hatch in May.

3. Nymph stage management

⑴ The locust larvae eat very little and like to eat fresh and tender plants. At this stage, the locusts are very fragile, so you should pay attention to rain protection to prevent the locust larvae from drowning. ⑵ The temperature should be controlled at 25-30℃, the light should be more than 12 hours, and the humidity should be kept at about 15%. Under these conditions, the locusts are most active, like to eat, and are conducive to growth. ⑶ The food intake of locust larvae above the third instar gradually increases. At this time, it is necessary to ensure that there is sufficient food in the shed, otherwise it will affect their normal growth and they will kill each other. ⑷ Keep the shed clean and clean it once every 1-2 days to prevent diseases.

locust

Locusts are also known as "grasshoppers" and are called "grass borers" in Taiwan. 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 legs are strong, 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. Diet: Likes to eat thick leaves, such as sweet potatoes, water spinach, etc. Metamorphosis: Incomplete metamorphosis

・After mating, the female locust inserts the ovipositor into the soil to a depth of 10 cm and lays about 50 eggs.

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

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. In the first one or two instars, nymphs look more like adults, but their heads and bodies are disproportionate. 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 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.

The hind leg segments of adults have a row of nipple-like protrusions that are equivalent to the springs, and the base of the radial veins of the forewings has thick veins that are equivalent to the 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.

・ Locusts are commonly known as "grasshoppers", and in Taiwanese they are called "grass moths". Their life cycle is egg e nymph e adult, and they undergo incomplete metamorphosis. They have chewing mouthparts and are herbivorous insects. Most of them are not picky eaters. In the wild grass, they are often seen chewing the leaves of grass plants one bite at a time. Their antennae are not as long as those of katydids, but they are short whip-like, but they have strong hind legs and can use jumping to avoid natural enemies. Sometimes you can see two locusts getting married, with the male on top and the female on the bottom.

・Oxya chinensis

Appearance characteristics: The male is 21-31mm long, and the female is 24-39mm long. The back of the body is gray-brown, and the abdomen and legs are green. The body color is quite different, which will be similar to the habitat and form a protective color. Ecological habits: Rice locusts are very common locusts in the grass on the plains and low-altitude areas, and two generations can occur each year.

・ The main reason why locusts move in groups is that they need high temperatures physiologically and can stay close together to keep warm.

・ The hind leg segments of adults have a row of nipple-like protrusions that are equivalent to the springs, and the base of the radial veins of the forewings has thick veins that are equivalent to the 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. Locusts can be divided into migratory and non-migratory types according to their living habits. Both types pose a great threat to crops, especially the former, which is very destructive. As long as it passes through, all green plants will be eaten up. The shock brought by the locust plague is really not flattering. Its diet is very diverse, eating all kinds of green plants, especially grass plants.

・ The nymphs are also called locusts. They look like adults, but they only have wing buds and are good at jumping. They need to shed their skin four to seven times before they can transform into adults that are good at jumping and flying. Some locusts have short antennae and short ovipositors. There are about 5,000 species of locusts in the world. The longest part of a locust's body is its hind legs, which are about the same length as its body. It can jump eight times the length of its body in one leap. The hind legs of a locust are also its best musical instrument. They can make sounds by rubbing against its wings.

・Classification: All insects belonging to the order Acridales in the order Orthoptera.

・ Species: There are approximately 12,000 species worldwide, and more than 100 species are currently known in Taiwan.

・ Life cycle: egg → nymph → adult.

・ Ecology

・ Appearance characteristics: Commonly known as grasshoppers, Taiwanese people call them grasshoppers. There is a folk song called "Grasshoppers Playing with Roosters", which describes the scene of this small insect teasing a big rooster. This was a common scene in Taiwan's countryside in the early years. Locusts passing through is a familiar idiom.

・Diet: They are herbivorous insects, and most of them are not particularly picky about food.

・ Another type: The ridged locust is accustomed to living on moist and exposed ground, and its main food is moss plants.

・ Habitat and protective coloration: The bird has a typical protective coloration, which allows it to hide well in the grass. Its hind legs are thick and well-developed, and it is good at jumping, which is its usual way of avoiding enemies when in danger.

・ Mating behavior: Compared with other insects, the mating time is longer, so the female is at the bottom and the male is at the top. It is not uncommon to see couples.

Appearance: The whole body is usually green, gray, brown or dark brown, 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, the exoskeleton is hard, and the tibia has sharp saw thorns, which are effective defensive weapons.

Locusts have well-developed hind legs, and can use them to jump distances several dozen times longer than their bodies. They are incompletely metamorphosed insects, and their larvae and adults are similar, with the only difference being the presence or absence of wings. The hind wings are translucent. The wings of some species of locusts have degenerated and become smaller, and some species, such as the diamond locust, have lost the ability to fly.

The body color is green or brown, regardless of the species; it is a protective color for the living environment. Locusts have large mouths and well-developed jaws, and feed on plant leaves. Locusts like to eat reeds, barnyard grass, white grass, sedge and wormwood, shrimp grass and sea salicornia. Some locust species are omnivorous and also eat dead insects, even the dead bodies of their own kind.

Male insects of some species make sounds to attract females, but they do so by rubbing their wings and hind legs together, unlike crickets, which use the sound organs in their front wings to make sounds.