Research work "Why do grasshoppers chirp"

A person loves to listen to the sounds of nature: the rustling of the wind in the grass or leaves, the murmur of a stream, the singing of birds, etc. All such sounds can have a beneficial effect on the mental state, calm after stress, and bring peace and tranquility.

Natural sounds that people enjoy include the sound of crickets. Or rather, this is not exactly singing - insects do not have a vocal apparatus, they can make sounds with other parts of the body. This method is called stridulation. In order to make sound, crickets and grasshoppers use special membranes located on the elytra.

Sounds of music

Any chirping by grasshoppers is not just for fun, but for a specific purpose. Most often, males attract females in this way. But scientists were able to find out that the different structure of the elytra is determined not only by the type of insect, but also by some features of its life and behavior. So, for example, those species of Orthoptera that chirp in tall grass, which can be an obstacle to the propagation of a sound signal, have a wider range of sound frequencies. This is necessary to increase immunity to interference. But species that chirp in flight make do well with a narrower frequency range - after all, in open space, sound travels very far.

What does the magpie bird mean?

Magpie is the bearer of news. Along with the dove, it is a symbol of the postal service. In Brittany, for example, meeting a magpie in the morning means that you will receive a letter in the afternoon. A killed magpie serves as a talisman for poultry.

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Treatment for tinnitus

The approach to treating tinnitus depends on the underlying disease:

If the examination reveals any pathological formation, surgical treatment is possible: removal of tumors, neuromas, sanitizing operations for otitis and labyrinthitis.
Conservative treatment of ear diseases . Treatment of otitis media, eustachitis, removal of sulfur plugs.
Arthrosis of the temporomandibular joint requires comprehensive treatment from a dentist or orthopedist.
Stopping medications that may be causing tinnitus.
physiotherapeutic interventions, methods of hyperbaric oxygenation, acupuncture, and laser therapy have been proposed for the treatment of tinnitus
For noise caused by muscle spasms, massage of the neck muscles, masticatory muscles, and stretching exercises for the masticatory muscles (moving the lower jaw forward) have a good effect.
Regardless of the etiology of the noise, psychotherapy is indicated for all patients. This method is aimed at reducing the patient’s fixation on his feelings and changing his attitude towards him.
Good results can be obtained by the method of biofeedback - training the patient to control his vegetative reactions.
The use of medications that can reduce noise or improve its tolerance.

Medicines used for tinnitus

As already mentioned, there is no single medication that specifically suppresses tinnitus. However, there are a number of drugs that significantly reduce the severity of noise if used taking into account the predominance of one or another mechanism.

Anticonvulsants. They have a good effect on muscle noise (convulsive contractions of the middle ear muscles, the tensor tympani muscle, the levator soft palate muscle). Drugs such as finlepsin, phenytoin, lamotrigine are used. The dosage is selected by an otoneurologist.

Why is he doing this?

Of course, nature tried for a reason. The complex structure of the elytra is given to crickets in order to simplify one of the most important purposes of the existence of individuals - leaving behind offspring. Therefore, males sing only during the mating season.

Why do crickets chirp? Musical abilities are given to them for communication with each other and for solving three problems at once:

The most important purpose of singing is to invite females to take part in procreation.
The mating song of a cricket is the most ear-pleasing “work” in the insect’s repertoire. It sounds unobtrusive, but at the same time very melodic. The male either makes ringing sounds or begins to crackle or buzz. It is not limited to singing alone: the trill is accompanied by a mating dance, in which even the mustache is involved. Several females may live on the territory of a male or in the neighborhood, and with his melodies he tries to keep them around him. Female crickets are not always loyal. If a new male who has settled nearby begins to emit a special and loud singing, then she may change her gentleman.
Marking the boundaries of your site. Crickets are characterized by solitary living, and each male has his own territory, in which he can allow several females to live. To make it clear to strangers that the area is occupied by it, the cricket emits shrill signals warning possible rivals.
If a skirmish could not be avoided, then the male tries to influence the enemy with sharp but loud sounds. Crickets are very aggressive. If two individuals get into a fight, then there is a high probability of the death of one of them. In this case, the winner can eat the loser. In the best case, the fight ends with the loss of antennae, legs or wings. In such a fight, the chirping is a kind of battle cry, designed to suppress the opponent and frighten him.

Only sexually mature individuals are capable of making sounds. Young males learn to do this by imitating their adult neighbors.

Where can you listen to cricket?

To get acquainted with the singing of crickets, just go out of town in the summer. These common insects are found almost everywhere. Their mating season begins with the onset of warm weather, and at this time ringing trills and threatening chirping are heard in the air. Crickets sing almost all day long. True, it is very difficult to get closer to the insect: it is very shy, and when a person approaches, it hides in its hole, from which it does not move far.

If it is not possible to meet a cricket in the wild, then there are many audio and video recordings of their sound on the Internet. They are pleasant to listen to, have a calming effect and promote relaxation.

Grasshoppers ignored ultrasonic signals from predator bats

oliver.dodd/flickr

Scientists have found that the grasshoppers of Neotropical forests use proactive measures to protect themselves from predators - chirping for no more than two seconds a night - although they hear the ultrasonic signals of bats and could only hide when they approach. The fact is that a third party enters into the relationship between predator and prey - other bats that do not feed on grasshoppers. Most of the echolocation signals belong to them, and the connection between ultrasound and the predator is disrupted. The article was published in the journal Proceedings of the Royal Society B: Biological Sciences

You can protect yourself from a predator in advance by avoiding meeting it. For example, camouflage or move less to be invisible. Such methods of protection are called proactive. If a predator is nearby or has already noticed the prey, it is necessary to act reactively - hide, defend or run away.

Each species, and sometimes individual individuals, has its own balance between proactive and reactive defense. Thus, many prey insects of bats have learned to hear the echolocation signals of predators and can act reactively - for example, change their flight course when they sense the approach of a hunter. And those insects that cannot distinguish ultrasound have to resort to proactive methods of protection: flying less often and more erratically, hiding in vegetation.

There are also less obvious situations. Many grasshoppers hear echolocation calls, and some species stop chirping when bats approach. However, the forests of the Neotropics (South and parts of Central America) are home to many different bats, all of which use echolocation, but many of which do not hunt grasshoppers. It is not clear how insects act in this situation - they defend themselves reactively and react to any ultrasonic signal, even if it does not signal danger, or they ignore the sounds of bats and are always careful - for example, they chirp less often.

A group of US scientists led by Laurel Symes from Cornell University conducted an experiment with representatives of 11 species of true grasshoppers ( Tettigoniidae

), which were collected on an island in Panama. The insects were kept in mesh cages at the edge of the forest and their chirping sounds were recorded for 24 hours. The grasshoppers were then played the sounds of fringed-lipped leaf-nosed bats ( Trachops cirrhosus

) or white noise and the chirping was recorded again.

In the second part of the experiment, the scientists recorded the activity of ultrasound-sensitive TN-1 neurons to ensure that the grasshoppers actually heard the bat calls.

TN-1 neurons from all 11 grasshopper species were found to be sensitive to ultrasonic signals. However, insects (except one species, Cocconotus wheeleri

) did not stop chirping when the sounds of bats were played for them. Half of the species chirped equally both under signals from leaf-nosed insects and under white noise or in silence; the rest made sounds under white noise more often than in the other two conditions.

In general, grasshoppers chirped rarely and made short sounds - in total, one grasshopper could be heard for only two seconds per night. And in a single species—the one that quieted down in response to calls from leaf-nosed insects—the chirping lasted an average of 22 seconds each night. Scientists have suggested that Neotropical grasshoppers prefer proactive defense and chirp less often so as not to give themselves away. Reacting to ultrasonic signals is apparently not very beneficial - after all, only four percent of such sounds can actually warn of danger.

It seems that a third party—bats that feed on other insects or fruit—can also interfere in the relationship between predator and prey. Trophically, they are not related to each other, but the presence of “safe” bats destroys the correspondence between the danger signal and the predator (ultrasound and leaf-nosed bat).

The diet of bats differs markedly between different groups: some feed on insects, some on larger animals, and others drink blood. The appearance of these bats is also varied, which is reflected in their fancy names. You can learn about all this from our test “Mouse (fly)”.

Alisa Bakhareva

Locust

It is possible that a locust or grasshopper is giving a concert in your garden. This is the closest relative of grasshoppers, found almost everywhere except in the coldest areas. They feed only on plants.

Locusts have become notorious for their monstrous appetite and ability to gather in swarms of billions. Every day, locusts eat as much plant food as they weigh. It would seem that this is not much, only 2 g, but a flock of a billion insects already absorbs 2000 tons! In Russia, locusts live in the lower reaches of the Volga, Ural, Don, and Terek.

Locusts (small species of locust) have more modest appetites, but are found everywhere. They can be seen even in the center of a large city.

Photo: www.globallookpress.com

Cicada

If the song comes from above, then most likely it is performed by a cicada, one of the worst enemies of plants. Adult insects suck juices from the leaves of grasses, shrubs and trees. The larvae hide in the ground and damage the roots.

Southern cicadas are large (body length - 2–6.5 cm, wingspan - up to 18 cm), and in Central Russia and to the north there live small cicadas - no more than 1 cm in height.

Photo: www.globallookpress.com

The cicada's body is wide and short, with two pairs of transparent wings on the sides. The head is wide, with large bulging eyes. The legs are strong, but cicadas cannot jump high, and they fly only so-so. More often they prefer to walk.

The cicada is much tougher to the touch than it looks, and its wings are so dense that you feel like you could cut yourself with them. But in reality they are harmless to humans.

Both male and female cicadas chirp, although the latter do this extremely rarely. But the males, wanting to attract “ladies,” fill the air with a very loud song - up to 100 decibels. Sometimes it can be heard from a distance of 800 meters.

Cricket Reproduction

Crickets have polygamous relationships, each male is the owner of a certain territory, which is inhabited by several females who are part of a kind of harem of this male. If another male encroaches on the territory of this male, fierce fights occur between them.

An obligatory attribute of the mating games of these insects is the famous trills of crickets, performing their musical serenades, the male attracts the female for mating.

Crickets breed throughout the year, but their peak sexual activity occurs in the summer. A fertilized female cricket prepares holes in the ground where she lays her eggs, somewhat similar to bananas. During one oviposition, a female cricket can lay from 40 to 179 eggs.

After one to two months (depending on the temperature and the environment in general), larvae begin to emerge from the eggs. The larva in its appearance resembles an adult cricket, but in order to become one, it will have to go through 10 molts, occurring over 7 weeks, during which the body undergoes restructuring. After the last molt, the larva produces a normal, mature cricket.

Appearance and features

Photo: What a grasshopper looks like

Grasshoppers are medium to large insects. The length of an adult varies from 1 to 7 centimeters, depending on the species. Like their relatives the katydids and crickets, grasshoppers have chewing mouths, two pairs of wings, one narrow and stiff, the other wide and flexible, and long hind legs for jumping. They differ from these groups in that they have short antennae that do not extend too far back to their bodies.

The femoral region of the upper hind limbs of the grasshopper is significantly enlarged and contains large muscles that make the legs well adapted for jumping. The male may produce a buzzing sound by either rubbing the forewings (Tettigoniidae) or rubbing tooth-like projections on the hind femurs against a raised vein on each closed forewing (Acrididae).

Grasshoppers typically have large eyes and are colored accordingly to blend in with their surroundings, usually a combination of brown, gray or green. Some species of males have bright colors on their wings, which they use to attract females. Several species feed on toxic plants and store the toxins in their bodies for protection. They are brightly colored to warn predators that they taste bad.

Female grasshoppers are larger than males and have sharp points on the end of their abdomens that help them lay eggs underground. The grasshopper's senses contact organs located in various parts of its body, including the antennae and palps on the head, the cerci on the abdomen, and the receptors on the legs. The organs of taste are located in the mouth, and the organs of smell are located on the antennae. The grasshopper hears using a tympanic cavity located either at the base of the abdomen (Acrididae) or at the base of each fore tibia (Tettigoniidae). His vision is carried out in the compound eyes, while changes in light intensity are perceived by the simple eyes.

How does a cricket sing?

The difference in structure between the male and female allows the former to make chirping sounds. The fact is that only male crickets have a special acoustic apparatus that allows crickets to sing, and serves them for certain purposes.

Cricket folds its wings horizontally

How do crickets make sounds? The insect's musical instrument is the elytra, and the mechanism of their operation during singing is reminiscent of playing the violin. They have veins, small wrinkles or folds. Their distribution over the surface is uneven, so when a certain area is exposed, a sound corresponding to it is produced. This makes the cricket's repertoire much richer than that of similar grasshoppers. The second elytra acts as a bridge with a jagged vein. The insect rubs its elytra against each other, creating vibration, and due to this, chirping appears. The intonation and nature of the “music” produced by the winged “singer” depends on the frequency of vibrations.

The sound apparatus of crickets is much more complex than that of grasshoppers. Therefore, it can produce a variety of sounds, each of which is suitable for a specific situation.

Built-in violin

The grasshopper performs incredibly beautiful melodies using its front wings. The grasshopper moves the jagged vein on the left wing, like a bow, along the “grater” on the right wing, and from it the vibrations are transmitted to a special vibrating membrane, the “mirror.”

The performer’s “track list” includes long, piercing invocation songs, short trills of warning to rivals, and a quiet, creaky ballad addressed to the lady of his heart. The male not only plays it - sometimes he also dances, swaying from side to side while performing.

The hearing organs of grasshoppers are located... on the shins of the front legs. The inside of the “ears” are very complex, but on the outside they look like membranes or narrow slits.

When they chirp

Typically, crickets begin making sounds after sunset. It is in complete darkness that these musicians leave their hiding places. In nature, where crickets are not negatively affected by human activity, it is not a problem to hear these insects even during the day. Day and night they can also be heard during the mating season. Silencing this “musician” is quite simple; just get close to him at a certain distance. Sensing danger, the cricket will immediately hide in its hole.

Interesting fact! At night, crickets feel safe, which is why they make sounds mainly after sunset.

The structural features of the acoustic apparatus of grasshoppers do not allow them to make sounds at night. As soon as dew begins to fall, the wet organ cannot make sounds. Therefore, grasshoppers chirp exclusively during the day.

The Japanese simply adore these little “musicians”, so many breed them at home to enjoy this melody all the time.

Brief information about the insect

Crickets are a family of orthoptera insects. Their closest relatives are grasshoppers, locusts, and cockroaches. From an evolutionary point of view, they all have a fairly respectable age, because their group was formed approximately 300 million years ago, during the Late Carboniferous era. This is 120 million years earlier than the beginning of the Jurassic period.

There are 2,300 species of this insect around the world. Most of them live in hot and humid climates, and only about 50 of them inhabit the territory of the CIS countries. The most common and famous of them are the field cricket (preferring life in fields, meadows and the edges of light deciduous forests) and the brownie, which chooses proximity to humans. It often climbs into houses and adjacent buildings, living in secluded corners and feeding on other insects.

Externally, a cricket looks like a grasshopper. But they differ in the structure of their legs and the way their wings fold. In addition, grasshoppers thrive in dry climates, while crickets prefer high humidity.

Links

Alexander Benediktov. Vibration alarm for insects of the family Tetrigidae (Orthoptera, Tetrigoidea) in Russia and adjacent territories.
Signals of Russian beetles
Orthoptera alarm
The British Library Sound Archive is an archive of over 150,000 recordings of animal and natural sounds.

Do you know? That crickets, like many living organisms, are able to perceive environmental sounds.

But, unlike the hearing organs familiar to us that mammals have - these are ears, the cricket does not have them. How do these insects pick up sound vibrations? These chirping inhabitants have tympanic organs. They are the hearing organs of crickets. Their location is very different from what we are used to. They are not located on the head at all, but on the front legs and the end of the abdomen and resemble the eardrum in our ear. It is capable of transmitting vibration of air or water, but, unlike the drum, it helps to perceive not only sound vibrations, but also all vibrations occurring in the environment. A person has a limited perception of the sounds made by insects, but each of us has heard the chirping of a cricket. He cannot make vocal sounds, but he can rub some parts of his body against others, the cricket's elytra participate in this process, and the well-known chirping vibrations are formed. This process is scientifically called stridulation. Crickets often use this mechanism within their species, for example, males invite females on a date this way. And this was proven by an interesting experiment, when the male began to chirp into the microphone of the phone, the female, hearing him, at the other end of the line, hurried to the phone. She heard him.

COMBINE USEFUL WITH PLEASANT!

Purpose Demonstrate how crickets make sounds. Materials

Clear adhesive tape
Cardboard card
Nail file or sandpaper

Progress

Use clear tape to secure one of the long sides of the card to the table.
Holding the other long side of the card by the corner, lift it about 5 cm above the table.
Slowly move the nail file back and forth along the raised edge of the card. Listen to the sound.
Repeat step “3” but move the nail file quickly.

Results Sound is produced. The faster you move the nail file, the higher the pitch of the sound. Why? The sound is produced when an uneven surface rubs against a sharp edge of something. In a male cricket, the uneven surface of one wing rubs against the sharp edge of the other wing. As with a nail file, the faster the wings move, the higher the frequency of the sound produced.

MORE FUN FACTS ABOUT CRICKETS!

It turns out that ambient temperature affects the speed at which these creaking creatures chirp. The hotter it is outside, the more intensely they will chirp. They are like thermometers that help determine the weather. This feature was noticed by physicists back in the 19th century. They tried to identify the relationship between the number of chirping sounds and the ambient temperature. Formulas were developed that helped calculate the relationship between these indicators.

You can try this too. To do this, you can visit a forest or park where you can clearly hear the chirping of crickets.

Try to count their chirps within 25 seconds. Happened?

Now divide the resulting number by 3, and then add another 4. You should get the air temperature at a given time. Try to compare with official information.

But it is worth remembering that such a temperature determination is only possible at ambient temperatures exceeding 13 °C. If it's cooler outside, the crickets simply won't sing. This temperature is uncomfortable for them, so they hide.

***

>Download – Crickets at nightSounds of nature

Description and types

Crickets are close relatives of grasshoppers and belong to the group of long-whiskered orthoptera insects. Their name comes from the Greek word for "singer".

Entomologists distinguish several families and varieties of crickets:

true - a family that is divided into 3 types: house, field and stem Far Eastern;
Ants, also called ant-lovers.

House cricket

The house cricket is an insect whose homeland is considered to be the Far East and North Africa, where they have long lived next to people: in residential and industrial buildings. In the warm months, crickets move closer to nature, and with the onset of cold weather they again return closer to the warmth of human habitation. In the field, they dig holes up to 30 cm deep, and when going hunting or patrolling the territory, they cover it with a tuft of grass.

As can be seen in the photo of a brownie cricket, it is a gray-yellow insect, decorated with variegated and brown spots on the body and three stripes on the ovoid head, the length of an adult is 15-25 mm. The eyes are located on both sides of the head. Long whiskers stick out in front, larger in size than the insect itself, they serve as an organ of touch. The body is covered with a special chitinous shell, which protects from external influences and reduces moisture loss in the body.

House cricket

This type of cricket has wings that help them fly to the right place; when folded, they look like elongated tails. However, these insects cannot truly fly. It has 3 pairs of limbs: the back ones are stronger - designed for jumping, the front 2 pairs - serve as auditory organs.

Only males can make sounds and “sing,” which they successfully use to attract the attention of females and procreate. The sound apparatus of crickets consists of a stridulatory vein, which acts as a bow when friction against the left elytra of the insect.

There are 3 types of sound signals: when searching for females, when courting, and “hostile” sounds to scare away other candidates for the role of suitors.

Interesting!

Many ancient beliefs say that if there is a cricket in a house, it brings good luck and happiness, protects its inhabitants from evil and disease, and “promises” an easy birth to pregnant women. Therefore, it is not customary to get rid of such “vocalists” as unwanted guests. However, not all owners like the arias of insects that interfere with sleep. Therefore, people prefer to get rid of singing crickets that have settled in the apartment.

Unlike domestic insects, having settled in the garden and multiplied in large numbers, crickets can become pests, nibbling vegetables, especially melons.

Field cricket: photo and description

field cricket

Insects of this species are common in Southern and Central Europe, Asia Minor and Western Asia, and North Africa. Habitats are well-lit fields and meadows, pine forests, where they make burrows up to 20 cm deep.

The dimensions of the field cricket are larger compared to other species: females are 17-22 mm, males are slightly larger (up to 26 mm). The body color is shiny black, sometimes brown, decorated with orange spots. The head is rounded with two antennae, and there are 3 ocellia (simple eyes) on the forehead.

Insects are omnivores, but prefer to feed on the leaves and roots of herbaceous plants, and occasionally catch small representatives of the fauna or eat their corpses.

Stem crickets

The Far Eastern or stem species belongs to the family of true crickets, another name is “eastern trumpeter”. Insects have a light green elongated body up to 13 mm long; a black stripe runs along the bottom of the abdomen.

They got their first name because females lay eggs in the stems or petioles of plants, in each clutch there are 2-4 eggs. Larvae emerge from eggs in mid-summer; they are smaller in size compared to adults; wings are present in the form of rudiments. In August-September they turn into adults.

The second of the names indicates where the cricket lives: it lives in the Russian Far East, as well as in China and Japan.

Ant lovers

The smallest in size - ant crickets - reach 3-5 mm, they have no wings, and in appearance they are similar to cockroach nymphs. They are not capable of making any sounds and cannot even hear them.

This family lives in South America, where it was discovered by the Swiss entomologist A. de Saussure at the end of the 19th century. Now this species is also found in Europe. Their place of residence is associated with ant nests: larvae and adults overwinter in the anthill, the development cycle of larvae from eggs lasts 24 months. and consists of 5 stages.

Ant lovers

House cricket

In the East, insects that produce beautiful melodies, such as the cricket and the cicada, were kept in special cages in homes, just like songbirds. And today, some exotic animal lovers keep crickets to enjoy their sounds.

To do this, use an aquarium, terrarium or special insectarium. Insects need systematic care. It is especially important to change the soil every 3 days, otherwise the unusual pet may die. Although crickets are predators in their natural habitat, when kept at home they are also fed plant foods: vegetables, fruits, and herbs.

The singing of crickets is very beautiful and varied. It's worth a trip out of town.