Why did many Hawaiian males stop singing?

A fly that finds crickets by their song

Pacific field cricket

Q: How to identify Pacific field cricket?

Look for six legs, antennae, three body sections and the shape of the wings. Beetles have hardened front wings; flies have just one working pair. Tiny insects may need a close view before their group is clear. Insect Identifier: upload a photo and compare the visible details.

Q: What does Pacific field cricket eat?

An omnivore, the Field Cricket eats a mix of plants, seeds, and smaller insects.

Q: How do field crickets chirp?

Only males chirp. A male raises his forewings and rubs a toothed vein, the file, against a hard scraper on the other wing. Thin wing panels called the harp and mirrors vibrate and make the sound loud. The Pacific field cricket’s song peaks at about 4.8 kHz.

Q: Why did crickets in Hawaii stop chirping?

A parasitoid fly, Ormia ochracea, finds male crickets by their song. On Kauai, a wing mutation called flatwing that makes males silent spread to more than 90% of males in fewer than 20 generations, because silent males survive.

Q: Where are a cricket’s ears?

On its front legs. Each front leg has two small eardrums on the shin, just below the knee.

Q: Can you tell the temperature from cricket chirps?

Roughly, for snowy tree crickets: Dolbear’s 1897 rule says count chirps in 15 seconds and add 40 to get °F. Field crickets, including this one, are much less reliable.

Q: What is a purring cricket?

A Pacific field cricket in Hawaii with heavily changed wings that makes a new sound called purring. Female crickets respond to purrs, but the song-hunting flies do not seem to.

Q: Are these the crickets people eat?

Usually not. The best-known farmed food cricket is the house cricket, Acheta domesticus, which European food-safety experts assessed as a novel food in 2021.

Q: Do field crickets bite?

They are harmless to people. A big cricket held in the hand may give a light nip with its jaws, which is a good reason to watch and not pick them up. Wash your hands if you touch one, and leave wild crickets where you found them.

Q: Is the Pacific field cricket endangered?

No assessment exists: the IUCN Red List has not evaluated it. It is common in coastal Australia and on many Pacific islands, though Hawaiian populations shrank after the parasitoid fly arrived.

Teleogryllus oceanicus

The Pacific field cricket (Teleogryllus oceanicus), also called the oceanic or Australian field cricket, is a large, dark cricket of coastal Australia and the Pacific islands, and was brought to Hawaii by people. Males sing at night by rubbing their forewings together, and females find them by ear. In Hawaii, a parasitoid fly that hunts by sound led to one of the fastest evolutionary changes seen in the wild: silent “flatwing” males.

Also known as Oceanic field cricket, Australian field cricket, Polynesian field cricket

Pacific field cricket abilities

≈4.8 kHz peak pitch of the calling song
A male sings by rubbing a toothed file on one forewing against a scraper on the other, many times a second.
- The calling song starts with a long chirp of 3 to 8 sound pulses, followed by a run of short chirps of 2 pulses each.
- Females recognise their own species from the rhythm alone: the pattern of gaps between pulses.
- Males use a calling song to attract females from afar and a different courtship song once a female is close.
- Night-time singing follows an inner body clock with a cycle of about 24 hours, which keeps running even without day and night cues.
Pulses per chirp
Long chirp (most)up to 8
Long chirp (fewest)3
Short chirp2
Females generally prefer songs with more long chirp.
Sources [1, 2, 13, 14, 15, 16]
3–9 kHz song pitches a flying female turns towards
Eardrums on the front legs pick up a male’s song, and also the high-pitched clicks of hunting bats.
- In flight tests, females turned towards song played at 3–9 kHz.
- When the same pattern was played at 30–70 kHz (ultrasound, like a bat’s calls), they turned away. Scientists think this helps crickets dodge bats at night.
- Ear nerve cells cluster around three pitch bands: up to 5.5 kHz, 10–12 kHz and 18 kHz or more.
Sources [5, 6, 9]
<20 generations for Kauai males to go silent
On Kauai, a wing mutation that wipes out the song spread to more than 90% of males in fewer than 20 generations.
- Flatwing males cannot sing, so the song-hunting fly cannot find them.
- A single gene on the X chromosome causes it. Silent males appeared on Oahu about two years after Kauai, from a different mutation with the same result.
- Since then, other silencing wing types, such as curly-wing, have spread in Hawaii too.
Sources [3, 17, 18, 19, 20]
0 notes sung by a satellite male
A silent male waits quietly near a singing male and meets the females that come to the song.
- Flatwing males on Kauai head towards calling song more strongly than normal males, which helps them meet females.
- What a young male hears while growing up shapes how he behaves as an adult, including whether he acts as a satellite.
Sources [17, 21]
Last 4 moults in which song circuits appear
Nymphs cannot sing. Their nerve circuits for singing build up over the last four moults before adulthood.
- Young crickets grow by moulting: they split their old outer skin and step out in a bigger one.
- In studies of crickets, the singing circuits were complete before the final moult but held back by signals from the brain until adulthood.
- Males become ready to mate about 10 days after their final moult.
Sources [8, 22]
33–42 mm female length with ovipositor
A female pushes her needle-like ovipositor into damp soil and lays her eggs underground.
- Eggs develop safely in the moist ground. In the lab, scientists check sand pads daily for up to 3 weeks for hatching.
- In Hawaii there are about 3–4 cricket generations a year.
Sources [4, 7, 8]
N₁₅ + 40 °F rule, for snowy tree cricketsStill debated
In 1897 Amos Dolbear showed that a cricket’s chirp rate tracks the temperature. His rule fits snowy tree crickets, not field crickets.
- Count the chirps of a snowy tree cricket in 15 seconds and add 40 to get a rough temperature in °F.
- Dolbear did not name his cricket; later researchers took it to be the snowy tree cricket, now called Oecanthus fultoni.
- Field crickets are much less reliable thermometers: age, mating success and other things change their chirp rate too.
Sources [23, 24]

Tap a pin on the model or a part below.

≈4.8 kHz peak pitch of the song
- Only males sing. A male lifts his tough forewings and rubs a toothed vein (the file) on one wing against a hard edge (the plectrum, or scraper) on the other.
- Thin, clear patches between the veins, the harp and the mirrors, vibrate like the skin of a drum and make the sound louder.
- The calling song is a nearly pure tone with a peak of about 4.8 kHz, close to the note the harp is built to ring at.
- In parts of Hawaii most males now have “flatwing” forewings without these parts, so they cannot sing.
Sources [1, 2, 3, 4]
2 eardrums on each front leg
- A cricket’s ears are on its front legs, on the shin (tibia) just below the “knee”.
- Each front leg has two thin eardrums (tympana). In a close relative, the hearing organ behind them is only about 0.2 mm across, one of the smallest ears of any animal.
- Scientists recording from Pacific field cricket ears tested sounds from 2 to 40 kHz and found nerve cells tuned to low, middle and very high pitches.
Sources [5, 6]
- The long, thin antennae feel and smell the world in the dark.
- When two crickets meet, they tap antennae. Chemicals on the body tell a male whether the other cricket is a female or a rival male.
Sources [7]
- Strong chewing mouthparts let the cricket eat both plant food and animal food: it is an omnivore.
- In research labs Pacific field crickets are raised on dry cat food and water, which shows how varied their diet can be.
Sources [8]
28–35 mm adult male length
- A large, dark brown to black cricket. Males are usually 28–35 mm long.
- Females measure 33–42 mm, partly because their long egg-laying tube adds to their length.
Sources [7]
- The big back legs are built for jumping away from danger.
- Adults can also fly. In flight tests, crickets steered towards or away from a sound by bending the abdomen and hind legs to one side, like a rudder.
Sources [9]
33–42 mm female length with ovipositor
- Only females have the long, needle-like ovipositor between the two tail feelers (cerci).
- She pushes it into damp ground and lays her eggs there. In the lab, females lay into pads of wet sand.
Sources [7, 8]
2° how precisely the fly finds a sound
- Ormia ochracea is a small North American fly that reached Hawaii by at least 1989. Females find singing male crickets by ear.
- Its ears are tuned near 5 kHz, the pitch of the cricket’s song, and work much more like a cricket’s ear than a normal fly’s.
- Although its two eardrums are less than 0.5 mm apart, it can point to a sound to within 2°, about as well as you can.
- The fly places tiny larvae on or near the singer; they burrow in and the cricket does not survive.
Sources [2, 10, 11, 12]

Real Pacific field crickets and relatives

Photos from Wikimedia Commons. Few photos of this species are there, so close relatives and its enemy fly are shown too, and labelled.

An adult Pacific field cricketPhoto: Caroline Harding, MAF, CC BY 3.0 AU
Its close look-alike, the Australian black field cricket (Teleogryllus commodus)Photo: Thomas Mesaglio, CC BY 4.0
FemaleForewings with a plain net of veins and no sound-making parts, plus a long ovipositor at the tail end.Finds males by ear and lays eggs in damp groundA female black field cricket (probably T. commodus), Tasmania: note the long ovipositor. Photo: Ghouston, CC0
NymphA smaller young cricket without full wings. It grows by moulting and gets working wings only at the final moult.Cannot sing until after the final moultA newly hatched nymph of a related Teleogryllus cricket (T. emma). Photo: Eastolany, CC BY-SA 4.0
Ormia ochracea, the fly that finds singing crickets by earPhoto: Jpaur, CC BY-SA 3.0
Australian black field cricket, a close relativePhoto: Jaco Grundling, CC0
A male European field cricket singing at its burrow, for comparisonPhoto: Rémi Chabert, CC BY-SA 4.0
Male European field cricket (Gryllus campestris), a different speciesPhoto: Gilles San Martin, CC BY-SA 2.0

Pacific field cricket by the numbers

Measured by scientists in the field and the lab.

Male length: 28–35 mm; adult males⁠[7]
Female length: 33–42 mm; including the ovipositor⁠[7]
Song pitch: ≈4.8 kHz; peak frequency of the nearly pure-tone calling song⁠[2]
Long chirp: 3–8 pulses; followed by short chirps of 2 pulses each⁠[13]
Ear range tested: 2–40 kHz; ear nerve cells cluster at ≤5.5, 10–12 and ≥18 kHz⁠[6]
Bat-dodge pitches: 30–70 kHz; flying females turned away from song played this high⁠[9]
Silent males on Kauai: >90%; flatwing within fewer than 20 generations; now close to all males⁠[17, 4]
Generations a year: 3–4; in Hawaii; 20 generations ≈ 5 to 7 years⁠[4]
Fly larvae carried: 57–517; tiny larvae held by one female parasitoid fly⁠[28]
Ready to mate: ≈10 days; after a male’s final moult (lab, 25 °C)⁠[8]

Pacific field cricket myths and facts

Chirping legs, cricket thermometers and silent islands: true or not?

0 of 8 answered

“Crickets chirp by rubbing their legs together.”
“A cricket’s ears are on its front legs.”
“You can tell the temperature by counting any cricket’s chirps.”
“Hawaiian crickets lost their song in just a few years.”
“A male that cannot sing can never find a mate.”
“The silent wing mutation spread from Kauai to the other islands.”
“The fly that hunts singing crickets can pinpoint a sound as well as you can.”
“The crickets people eat are mostly field crickets like this one.”

Pacific field cricket records

Evolution in fast-forward, and an enemy with very sharp ears.

One of the fastest changes seen in the wild
<20 generations
Kauai Pacific field crickets
from singing to more than 90% silent males; a textbook example of rapid evolution⁠[17, 4]
A brand-new cricket song
Purring
Purring Pacific field crickets, Hawaii
a new song described in 2018, unlike that of any other known cricket⁠[26]
Same silence, two different genes
2 origins
Kauai and Oahu flatwings
separate mutations on two islands gave the same silent result⁠[3]
Tiny ears, sharp aim
2°
Ormia ochracea, the cricket’s enemy
finds a singing cricket as precisely as a human locates a sound, with eardrums less than 0.5 mm apart⁠[12]

A Pacific field cricket’s life

From an egg in damp soil to a singing adult.

Egg
Laid in damp ground
The female pushes her ovipositor into moist soil or sand and lays her eggs.⁠[7, 8]
Hatching
A tiny nymph
A wingless nymph hatches. It looks like a small adult without wings and cannot sing.⁠[22]
Growing up
Moult after moult
The nymph grows by moulting. Over the last four moults, its singing circuits build up.⁠[22]
Final moult
Adult with wings
After the last moult it has full wings. Males are ready to mate about 10 days later.⁠[8]
Night
Singing time
Males sing at night, timed by an inner clock. In Hawaii, singing can attract a deadly parasitoid fly.⁠[16, 17]
Mating
Following the song
Females follow the song to a male. Then the cycle starts again.⁠[9, 13]
A year
3–4 generations
In warm Hawaii the crickets breed all year, with about 3–4 generations a year.⁠[4, 21]

How Hawaii’s Pacific field crickets went silent

A fly that hunts by ear arrived, and within a few years most males on Kauai had stopped singing.

By 1877
Crickets reach Hawaii
Pacific field crickets were in Hawaii by at least 1877, possibly brought much earlier by Polynesian settlers. Hawaiian crickets are most closely related to those of the Society and Cook Islands.⁠[10, 30]
By 1989
A listening fly arrives
Ormia ochracea, a North American fly that finds crickets by their song, was in Hawaii by at least 1989.⁠[10, 2]
2003
Silent males on Kauai
Males with flat, songless “flatwing” wings were first seen on Kauai.⁠[4]
~2005
Silence on Oahu
About two years later, flatwings appeared on Oahu, from a different mutation.⁠[3]
2006
“Silent night”
Scientists reported that more than 90% of Kauai males had gone silent in fewer than 20 generations.⁠[17]
2008
One gene
Breeding tests showed flatwing is controlled by a single gene on the X chromosome.⁠[18]
2018
Purring crickets
A new song, purring, made with heavily changed wings, was described. Female crickets respond to it.⁠[26, 15]
2021
A secret channel
Field tests found that female crickets respond to purrs but the flies do not, a kind of private conversation.⁠[2]
2024
Curly-wing too
A third silencing form, curly-wing, now lives alongside flatwing in several Hawaiian populations.⁠[20]

Pacific field cricket vs house cricket vs European field cricket

Three crickets that are easy to mix up, side by side.

Pacific field cricket vs house cricket vs European field cricket
	Pacific field cricket	House cricket	European field cricket
Scientific name⁠[31, 32, 33]	Teleogryllus oceanicus	Acheta domesticus	Gryllus campestris
Where⁠[7, 29, 34]	Coastal Australia and Pacific islands, including Hawaii (introduced)	Widely kept and farmed by people	Europe
Male length⁠[7, 34]	28–35 mm	—	19–23 mm
Can adults fly?⁠[9, 34]	Yes	—	No, flightless
Where males sing⁠[16, 34]	At night, out in the grass	—	At the mouth of a burrow
Farmed as human food⁠[29]	No	Yes, assessed as a novel food in the EU	No
IUCN Red List (global)⁠[31, 32, 33]	Not evaluated	Not evaluated	Not evaluated

“—” means we found no reliable figure to compare.

Is the Pacific field cricket endangered?

Not as far as anyone knows. It is common across its range, but nobody has assessed it for the IUCN Red List.

IUCN Red List

Not Evaluated (NE)

Trend unknown

GBIF lists the species as Not Evaluated. It is widespread in coastal Australia and on many Pacific islands.⁠[31, 7]

Not evaluated by the IUCN Red List

Threats

A deadly fly in Hawaii
The introduced parasitoid fly kills singing males. Genetic studies suggest Hawaiian populations shrank sharply after it arrived.⁠[17, 35]
Low genetic variety on islands
Genetic variety is highest in Australia and lowest in Hawaii, after repeated island hops.⁠[30]
Light at night
Lab studies show that artificial light at night while crickets grow up can affect their later breeding.⁠[36]

What’s helping

Watched by scientists
Hawaiian populations have been studied for over 20 years, so changes are noticed quickly.⁠[4, 35]
Darker nights
Turning off or shading outdoor lights helps night insects. Scientists are still testing how much it helps this cricket.⁠[36]
Watch, don’t collect
Listen for singing males after dark and watch with a dim torch, then leave them where they are.

A rarer relative

European field cricket (Gryllus campestris)Not Evaluated
Flightless and slow to spread. In the UK it fell to a single colony of about 100 crickets in the early 1990s and conservationists have bred it in captivity to help it recover.⁠[34, 33]

Pacific field cricket quiz

12 questions. Every answer is somewhere on this page.

Question 1 of 12Score 0

What does a male Pacific field cricket rub together to sing?

Pacific field cricket field notes

Diet, food web, safety and badges from the Snappit field guide.

Diet & Feeding

An omnivore, the Field Cricket eats a mix of plants, seeds, and smaller insects.

Primary Foods

Grass
Leaves
Seeds
Decaying plant matter
Small insects
Foraging Method: Foraging

Ecological connections

House SparrowEaten by
A common bird that preys on crickets in urban and rural areas.
Black RatEaten by
Rats are opportunistic predators and will consume crickets when available.
Parasitoid FlyParasite
A parasitoid fly that finds male crickets by their song. In Hawaii it kills singing males.
Perennial RyegrassEats
A common grass species that crickets feed on in lawns and pastures.

Safety

Danger 1/5 · Very low

Do not pick up wild crickets. They are harmless, but a big one may give a light nip. Wash your hands if you touch one, and ask an adult for help.

Traits

Collections

Classification

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Family: Gryllidae
Genus: Teleogryllus

Sources for these Pacific field cricket facts

36 studies and references · checked Oct 16, 2026

Frequently Asked Questions

How to identify Pacific field cricket?

Look for six legs, antennae, three body sections and the shape of the wings. Beetles have hardened front wings; flies have just one working pair. Tiny insects may need a close view before their group is clear. Insect Identifier: upload a photo and compare the visible details.

What is Pacific field cricket's wingspan?

40-60 mm

How big is Pacific field cricket?

28-42 mm

How long does Pacific field cricket live?

60-90 days

What does Pacific field cricket eat?

An omnivore, the Field Cricket eats a mix of plants, seeds, and smaller insects.

Where is Pacific field cricket usually found?

Fields and meadows

How many legs does Pacific field cricket have?

How do field crickets chirp?

Only males chirp. A male raises his forewings and rubs a toothed vein, the file, against a hard scraper on the other wing. Thin wing panels called the harp and mirrors vibrate and make the sound loud. The Pacific field cricket’s song peaks at about 4.8 kHz.

Why did crickets in Hawaii stop chirping?

A parasitoid fly, Ormia ochracea, finds male crickets by their song. On Kauai, a wing mutation called flatwing that makes males silent spread to more than 90% of males in fewer than 20 generations, because silent males survive.

Where are a cricket’s ears?

On its front legs. Each front leg has two small eardrums on the shin, just below the knee.

Can you tell the temperature from cricket chirps?

Roughly, for snowy tree crickets: Dolbear’s 1897 rule says count chirps in 15 seconds and add 40 to get °F. Field crickets, including this one, are much less reliable.

What is a purring cricket?

A Pacific field cricket in Hawaii with heavily changed wings that makes a new sound called purring. Female crickets respond to purrs, but the song-hunting flies do not seem to.

Are these the crickets people eat?

Usually not. The best-known farmed food cricket is the house cricket, Acheta domesticus, which European food-safety experts assessed as a novel food in 2021.

Do field crickets bite?

They are harmless to people. A big cricket held in the hand may give a light nip with its jaws, which is a good reason to watch and not pick them up. Wash your hands if you touch one, and leave wild crickets where you found them.

Is the Pacific field cricket endangered?

No assessment exists: the IUCN Red List has not evaluated it. It is common in coastal Australia and on many Pacific islands, though Hawaiian populations shrank after the parasitoid fly arrived.

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