Learn About Cicadas

In this episode of the I Can't Sleep Podcast, drift off to sleep while learning about cicadas. Sure, they might not be the most captivating insects, but there's a lot to know about them, and they certainly make a loud noise. So, settle in, relax, and happy sleeping!

Transcript

Welcome to the I Can't Sleep Podcast,

Where I read random articles from across the web to bore you to sleep with my soothing voice.

I'm your host,

Benjamin Boster.

Today's episode is from a Wikipedia article titled,

Cicada.

The cicadas are a superfamily of Cicadoidea,

Of insects in the order Hemiptera,

True bugs.

The superfamily is divided into two families,

The Tedigarctidae with two species in Australia,

And the Cicadoidea with more than 3,

000 species described from around the world.

Many species remain undescribed.

Nearly all of cicada species are annual cicadas,

With the exception of the few North American periodical cicada species,

Genus Maja cicada,

Which in a given region emerge in mass every 13 or 17 years.

Cicadas have prominent eyes set wide apart,

Short antennae,

And membranous front wings.

They have an exceptionally loud song,

Produced in most species by the rapid buckling and unbuckling of drum-like timbals.

The earliest known fossil cicadomorpha appeared in the Upper Permian period,

Extant species occur all over the world,

Intemperate to tropical climates.

They typically live in trees,

Feeding on watery sap from xylem tissue,

And laying their eggs in a slit in the bark.

Most cicadas are cryptic.

The vast majority of species are active during the day as adults,

With some calling at dawn or dusk.

Only a rare few species are known to be nocturnal.

One exclusively North American genus,

Maja cicada,

The periodical cicadas,

Which spend most of their lives as underground nymphs,

Emerge in predictable intervals of 13 or 17 years,

Depending on the species and the location.

The unusual duration and synchronization of their emergence may reduce the number of cicadas lost to predation,

Both by making them a less reliably available prey,

So that any predator that evolved to depend on cicadas for sustenance might starve waiting for their emergence,

And by emerging in such huge numbers that they will satiate any remaining predators before losing enough of their number to threaten their survival as a species.

The annual cicadas are species that emerge every year,

Though these cicadas' life cycles can vary from one to nine or more years as underground nymphs.

Their emergence above ground as adults is not synchronized,

So some members of each species appear every year.

Cicadas have been featured in literature since the time of Homer's Iliad,

And as motifs in art from the Chinese Shang Dynasty.

They have also been used in myth and folklore as symbols of carefree living and immortality.

The cicada is also mentioned in Hesiod's Shield,

In which it is said to sing when millet first ripens.

Cicadas are eaten by humans in various parts of the world,

Including China,

Myanmar,

Malaysia,

And Central Africa.

At least 3,

000 cicada species are distributed worldwide in essentially any habitat that has deciduous trees,

With the majority being in the tropics.

Most genera are restricted to a single biogeographical region,

And many species have a very limited range.

This high degree of endemism has been used to study the biogeography of complex island groups,

Such as in Indonesia and Asia.

There are several hundred described species in Australia and New Zealand,

Around 150 in South Africa,

Over 170 in America north of Mexico,

At least 800 in Latin America,

And over 200 in Southeast Asia and the Western Pacific.

About 100 species occur in the Palearctic.

A few species are found in southern Europe,

And a single species was known from England,

The new forest cicada,

Cicadata montana,

Which also occurs in continental Europe.

Many species await formal description,

And many well-known species are yet to be studied carefully,

Using modern acoustic analysis tools that allow their songs to be characterized.

Many of the North American species are the annual or jarfly or dogfly cicadas,

So named because they emerge in late July and August.

The best known North American genus,

However,

May be magicicada.

These periodical cicadas have an extremely long life cycle of 13 or 17 years,

With adults suddenly and briefly emerging in large numbers.

Australian cicadas are found on tropical islands and cold coastal beaches around Tasmania,

In tropical wetlands,

High and low deserts,

Alpine areas of New South Wales and Victoria,

Large cities including Sydney,

Melbourne and Brisbane,

And Tasmanian highlands and snowfields.

Many of them have common names such as cherry nose,

Brown baker,

Red eye,

Green grocer,

Yellow monday,

Whiskey drinker,

Double drummer,

And black prince.

The Australian green grocer is among the loudest insects in the world.

More than 40 species from five genera populate New Zealand,

Ranging from sea level to mountaintops,

And are all endemic to New Zealand and its surrounding islands.

One species is found on Norfolk Island,

Which technically is part of Australia.

The closest relatives of the New Zealand cicadas live in New Caledonia and Australia.

Cicadas are large insects made conspicuous by the courtship calls of the males.

They are characterized by having three joints in their tarsae,

And having small antennae with conical bases in three to six segments,

Including a seta at the tip.

Cicadas are feeble jumpers,

And nymphs lack the ability to jump altogether.

Another defining characteristic is the adaptations of the forelimbs of nymphs for underground life.

The relic family Tedigarctidae differs from the cicadidae in having the prothorax extending as far as the scotellum,

And by lacking the tympanal apparatus.

The adult insect known as Inimago is two to five centimeters in total length in most species.

The largest,

The Empress cicada,

Has a head body length around seven centimeters,

And its wingspan is 18 to 20 centimeters.

Cicadas have prominent compound eyes set wide apart on the sides of the head.

The short antennae protrude between the eyes,

Or in front of them.

They also have three small ocelli located on the top of the head in a triangle between the two large eyes.

This distinguishes cicadas from other members of the Hemiptera.

The mouthparts form a long,

Sharp rostrum that they insert into the plant to feed.

The posclippius is a large nose-like structure that lies between the eyes and makes up most of the front of the head.

It contains the pumping musculature.

The thorax has three segments and houses the powerful wing muscles.

They have two pairs of membranous wings that may be hyaline,

Cloudy,

Or pigmented.

The wing venation varies between species and may help in identification.

The middle thoracic segment has an operculum on the underside,

Which may extend posteriorly and obscure parts of the abdomen.

Desert cicadas are unusual among insects in controlling their temperature by evaporative cooling,

Analogous to sweating in mammals.

When their temperature rises above 39 degrees Celsius,

They suck excess sap from the food plants and extrude the excess water through pores in the pterygium at a modest cost in energy.

Such a rapid loss of water can be sustained only by feeding on water-rich xylem sap.

At lower temperatures,

Feeding cicadas would normally need to excrete the excess water.

By evaporative cooling,

Desert cicadas can reduce their bodily temperature by some 5 degrees Celsius.

Some non-desert cicada species also cool themselves evaporatively but less dramatically.

Conversely,

Many other cicadas can voluntarily raise their body temperatures as much as 22 degrees Celsius above ambient temperature.

The singing of male cicadas is produced principally and in the majority of species using a special structure called a tymbal,

A pair of which lies between each side of the anterior abdominal region.

The structure is buckled by muscular action and being made of resulin,

Unbuckles rapidly on muscle relaxation,

Producing their characteristic sounds.

Some cicadas,

However,

Have mechanisms for stradulation,

Sometimes in addition to the tymbals.

Here,

The wings are rubbed over a series of mid-thoracic ridges.

In a Chinese species,

Both males and females can stridulate.

The sounds may further be modulated by membranous coverings and by resonant cavities.

The male abdomen in some species is largely hollow and acts as a soundbox.

By rapidly vibrating these membranes,

The cicada combines the clicks into apparently continuous nodes.

Enlarged chambers derived from the trachea serve as resonance chambers with which it amplifies the sound.

The cicada also modulates the song by positioning its abdomen toward or away from the substrate.

Partly by the pattern in which it combines the clicks,

Each species produces its own distinctive mating songs and acoustic signals,

Ensuring that the song attracts only appropriate mates.

Average temperatures of the natural habitat for the South American species Phidicinarana is about 29 degrees Celsius.

During sound production,

The temperature of the tymbal muscles was found to be significantly higher.

Many cicadas sing most actively during the hottest hours of a summer day,

Roughly a 24-hour cycle.

Most cicadas are diurnal in their calling and depend on external heat to warm them up,

While a few are capable in raising their temperatures using muscle action,

And some species are known to call a dusk.

Other species are among the few that are known to be truly nocturnal,

And there may be other nocturnal species living in tropical forests.

Cicadas call from varying heights on trees.

Where multiple species occur,

The species may use different heights and timing of calling.

While the vast majority of cicadas call from above the ground,

Two Californian species are known to call from hollows made at the base of the tree below the ground level.

The adaptive significance is unclear,

As the calls are not amplified or modified by the burrow structure,

But this may avoid predation.

Although only males produce the cicada's distinctive sounds,

Both sexes have membranous structures called tympana,

Singular tympanum,

By which they detect sounds,

The equivalent of having ears.

Males disable their own tympana while calling,

Thereby preventing damage to their hearing,

A necessity partly because some cicadas produce sounds up to 120 decibels,

Which is among the loudest of all insects produce sounds.

A song is loud enough to cause permanent hearing loss in humans,

Should the cicada be at a close range.

In contrast,

Some small species have songs so high in pitch that they are inaudible to humans.

For the human ear,

Telling precisely where a cicada's song originates is often difficult.

The pitch is nearly constant,

The sound is continuous to the human ear,

And cicadas sing in scattered groups.

In addition to the mating song,

Many species have a distinct distress call,

Usually a broken and erratic sound emitted by the insect when seized or panicked.

Some species also have courtship songs,

Generally quieter,

And produced after a female has been drawn as a calling song.

Males also produce encounter calls,

Whether in courtship or to maintain personal space within choruses.

The songs of cicadas are considered by entomologists to be unique to a given species,

And a number of resources exist to collect and analyze cicada sounds.

In some species of cicadas,

The males remain in one location and call to attract females.

Sometimes,

Several males aggregate and call in chorus.

In other species,

The males move from place to place,

Usually with quieter calls,

While searching for females.

Ptetigartidae differ from other cicadas in producing vibrations in the substrate rather than audible sounds.

After mating,

The female cuts slits into the bark of a twig where she deposits her eggs.

Both male and female cicadas die within a few weeks after emerging from the soil.

Although they have mouthparts and are able to consume some plant liquids for nutrition,

The amount eaten is very small,

And the insects have a natural adult lifespan of less than two months.

When the eggs hatch,

The newly hatched nymphs drop to the ground and burrow.

Cicadas live underground as nymphs for most of their lives at depths down to about 2.

5 meters.

Nymphs have strong front legs for digging and excavating chambers near to roots,

Where they feed on xylem sap.

In wet habitats,

Larger species construct mud towers above ground to aerate their burrows.

In the final nymph instar,

They construct an exit tunnel to the surface and emerge.

They then molt on a nearby plant for the first time and emerge as adults.

The abandoned exoskeletons remain,

Still clinging to the bark of the tree.

Most cicadas go through a life cycle that lasts two to five years.

Some species have much longer life cycles,

Such as the North American genus magicicada,

Which has a number of distinct broods that go through either a 17-year or in some parts of the region a 13-year life cycle.

The long life cycles may have developed as a response to predators,

Such as the cicada killer wasp and praying mantis.

A specialist predator with a shorter life cycle of at least two years could not reliably prey upon the cicadas.

For example,

A 17-year cicada with a predator with a five-year life cycle will only be threatened by a peak predator population every 85 years,

While a non-prime cycle such as 15 would be endangered at every year of emergence.

An alternate hypothesis is that these long life cycles have evolved during the ice ages so as to overcome cold spells,

And that as species co-emerged and hybridized,

They left distinct species that did not hybridize having periods matching prime numbers.

The 13- and 17-year cicadas only emerge in the Midwestern and Eastern U.

S.

In the same year every 221 years,

With 2024 being the first such year since 1803.

Cicada nymphs drink sap from the xylem of various species of trees,

Including oak,

Cypress,

Willow,

Ash,

And maple.

While common folklore indicates that adults do not eat,

They actually do drink plant sap.

Cicadas are not adapted for jumping.

They have the usual insect modes of locomotion,

Walking and flight,

But they do not walk or run well,

And take to the wing to travel distances greater than a few centimeters.

Cicadas are commonly eaten by birds and mammals,

As well as bats,

Wasps,

Mantises,

Spiders,

And robber flies.

In times of mass emergence of cicadas,

Various amphibians,

Fish,

Reptiles,

Mammals,

And birds change their foraging habits so as to benefit from the glut.

Newly-hatched nymphs may be eaten by ants,

And nymphs living underground are preyed on by burrowing mammals.

In northern Japan,

Brown bears prey on final N-star nymphs of cicadas during summer by digging up the ground.

A catechid predator from Australia is capable of attracting single male cicadas of a variety of species by imitating the timid,

Click replies of sexually receptive female cicadas,

Which respond in pair formation by flicking their wings.

Their prime number life cycle prevents predators with a life cycle of two or more years from synchronizing with their emergence.

Plants can also defend themselves against cicadas.

Although cicadas can feed on the roots of gymnosperms,

It has been found that resinous conifers such as pine do not allow the eggs of magi-cicada to hatch,

The resin sealing up the egg cavities.

Cicadas use a variety of strategies to evade predators.

Large cicadas can fly rapidly to escape if disturbed.

Many are extremely well camouflaged to evade predators,

Such as birds that hunt by sight.

Being colored like tree bark and disruptively patterned to break up their outlines,

They are difficult to discern.

Their partly transparent wings are held over the body and pressed close to the substrate.

Some cicada species play dead when threatened.

Some cicadas display bright dematic flash coloration on their hind wings when threatened.

The sudden contrast helps to startle predators,

Giving the cicadas time to escape.

Most cicadas are diurnal and rely on camouflage when at rest,

But some species use aposematism-related Batesian mimicry,

Wearing the bright colors that warn of toxicity in other animals.

One species has conspicuous red and black warning coloration,

Is diurnal,

And boldly flies about in full view of possible predators.

Some predators hunt cicadas by sound,

Being attracted to their songs.

Singing males soften their songs so that the attention of the listener gets distracted to neighboring louder singers,

Or cease singing altogether as a predator approaches.

A loud cicada song,

Especially in chorus,

Has been asserted to repel predators,

But observations of predator responses refute the claim.

Cicadas have been featured in literature since the time of Homer's Iliad,

Meant as motifs in decorative art from the Chinese Zheng dynasty.

They are described by Aristotle in his History of Animals and by Pliny the Elder in his Natural History.

Their mechanism of sound production is mentioned in Hesiod in his poem Works and Days,

When the scolimus flowers and the tuneful tetics sitting in his tree in the weary summer season pours forth from under his wings his shrill song.

In the classical 14th-century Chinese novel Romance of the Three Kingdoms,

Diachen took her name from the sable trails and jade decorations in the shape of cicadas.

Which adorns the hats of high-level officials.

Cicadas are a frequent subject of haiku,

Where,

Depending on type,

They can indicate spring,

Summer,

Or autumn.

Sean Tan's illustrated book Cicada tells the story of a hard-working but underappreciated cicada working in an office.

Brandon Jacobs Jenkins' play Appropriate takes place on an Arkansas farm in summer and calls for the sounds of cicadas to underscore the entire show.

Cicadas were eaten in ancient Greece and are consumed only in selected regions in modern China,

Both as adults and more often as nymphs.

Cicadas are also eaten in Malaysia,

Burma,

North America,

And Central Africa,

As well as the Balochistan region of Pakistan,

Especially in Ziarad.

Female cicadas are prized for being meatier.

Shells of cicadas are employed in traditional Chinese medicines.

The 17-year Onondaga brood,

Magi-Cicada,

Is culturally important and a particular delicacy to the Onondaga people and are considered a novelty food item by modern consumers in several states.

Cicadas are featured in the protest song Como La Chigarra,

Like the cicada.

Written by Argentinian poet and composer Maria Elena Walsh.

In the song,

The cicada is a symbol of survival and defiance against death.

The song was recorded by Mercedes Sosa,

Among other Latin American musicians.

In North America and Mexico,

There is a well-known song,

La Chigarra,

The cicada,

Written by Raimundo Perez Soto,

Which is a song in the Mariachi tradition that romanticizes the insect as a creature that sings until it dies.

Brazilian artist Lenine,

With his track Malavadiza from the album Chao,

Creates a song built upon the sound of the cicada that can be heard along the track.

Cicada sounds heavily feature in the 2021 album Solar Power by New Zealand artist Lord.

She describes cicada song as being emblematic of the New Zealand summer.

Cicadas have been used as money in folk medicine to forecast the weather,

To provide song in China,

And in folklore and myths around the world.

In France,

The cicada represents the folklore of Provence and the Mediterranean cities.

The cicada has represented in Soussian since classical antiquity.

Jean de La Fontaine began his collection of fables,

Les Fables de la Fontaine,

With a story La Cigale La Forme,

The Cicada and the Ant,

Based on one of Aesop's fables.

In it,

The cicada spends the summer singing while the ant stores away food,

And the cicada finds herself without food when the weather turns bitter.

In Chinese tradition,

The cicada symbolizes rebirth and immortality.

The Chinese essay 36 Stratagems,

The phrase,

To shed the golden cicada skin,

Is the poetic name for using a decoy to fool enemies.

In the Chinese classic novel Journey to the West,

16th Century,

The protagonist Priest of Tang was named the Golden Cicada.

In Japan,

The cicada is associated with the summer season.

For many Japanese people,

Summer hasn't officially begun until the first songs of the cicada are heard.

According to Lafcadio Hearn,

The song of Meimuna Apollifera,

Called Tsukutsukoboshi,

Is said to indicate the end of summer,

And is called so because of its particular call.

In the Homeric hymn to Aphrodite,

The goddess Aphrodite retells the legend of how Eos,

The goddess of the dawn,

Requested Zeus to let her lover Tithonus live forever as an immortal.

Zeus granted her request,

But because Eos forgot to ask him to also make Tithonus ageless,

Tithonus never died,

But he did grow old.

Eventually,

He became so tiny and shriveled that he turned into the first cicada.

The Greeks also used a cicada sitting on a harp as an emblem of music.

In Kapampangna mythology in the Philippines,

The goddess of dusk,

Sisalem,

Is said to be greeted by the sounds and appearances of cicadas whenever she appears.

Reviews

BB reads me the best boring articles every night! Thank you BB!!

Thank you! It was zzzzzz….except the part about their eyes was kind of creepy! 😂😂😂😂