New cricket species sings at night and challenges beliefs about tropical ecosystems

Silent Valley National Park in Kerala has long been known for an unusual quiet. The name dates to 1847 when British visitors noted a lack of cicada hum, according to the state tourism history. That image is changing with the formal description of a forest cricket from the park, Ajareta sairandhriensis.

A peer reviewed study established a new genus, a taxonomic rank for closely related species, and named Ajareta sairandhriensis along with two relatives from southern India.

What changed in Silent Valley

Dhaneesh Bhaskar of the IUCN Species Survival Commission Grasshopper Specialist Group documented the species and its calling behavior. His role connects field observations with the taxonomy presented in the paper.

Male callers use cavities in dead wood, and the chorus rises on full moon nights with a blend of trills and chirps near 3.3 kilohertz. 

“The soundscape inside Silent Valley is not at all silent, especially during the night.” said Dhaneesh Bhaskar, IUCN Species Survival Commission Grasshopper Specialist Group (IUCN).

Meet Ajareta sairandhriensis

Ajareta sits within Landrevinae, a cricket subfamily, a rank below family, whose members are mainly nocturnal and live under bark.

The revision clarifies names, narrows older genera, and sets clear identification features for males and females.

Ajareta kervasae comes from the Kervasae Reserve Forest in Karnataka, and Ajareta meridionalis from the Chalakudy region of Kerala. Ajareta sairandhriensis honors “Sairandhri,” the local name for Silent Valley.

The authors report Ajareta as likely endemic, restricted to the Indian subcontinent, and well represented in evergreen forests. That pattern hints that more species may be found as under sampled areas are surveyed.

How a small insect gets loud

Crickets produce sound by stridulation, rubbing forewings that bear file and scraper structures. The song carries information about species identity, location, and readiness to mate.

Some species boost loudness by choosing helpful sites that shape their sound. A classic review shows that field crickets often sing at burrow mouths where horn shaped openings can add many decibels.

Others even use external objects as tools to amplify calls. One paper showed tree crickets like Ajareta sairandhriensis build leaf baffles that raise call levels and extend the distance over which mates can hear them.

Light at night does not affect every species in the same way. Multi-year research from tropical forests found that the influence of moonlight on calling varies by species and can be modest.

An evergreen canopy blocks much of the sky glow, so full moons may still yield dim forest floors. That is a natural setting where sound beats sight for finding a partner.

A caller seated in a tree cavity gets the safety of cover and a shaped opening that directs sound outward. That placement can also reduce obstacles between sender and receiver.

Ajareta sairandhriensis conservation

Songs help scientists sort species that look similar. They also make a bioindicator, a species whose presence or activity signals habitat quality, very practical because calls are easy to detect.

Because these crickets favor native evergreen forest, listening surveys can guide both protection and restoration. Automated methods now scan long recordings for target patterns and estimate when and where callers are active.

A single discovery can recalibrate a park’s reputation. The quiet label came from a cicada story, yet nights hold a layered chorus that includes this cricket and many other animals.

Why Ajareta sairandhriensis matters

Taxonomic changes are not just new names. Each clarified subfamily and genus points to a distinct history of how lineages split and settled across the ranges of the Western Ghats.

When older Indian species move from Landreva into Ajareta, comparisons become sharper and future surveys get a shared label that matches anatomy and geography. That consistency helps field teams gather cleaner data.

Adding sound recordings and precise locations will support long term monitoring. Numbers on frequency, timing, and site choice can track how lighting at night or forest structure shapes behavior across seasons.

Silent Valley’s name comes from a story about missing cicadas in the deep interior. The new cricket, Ajareta sairandhriensis, turns that story into a measurable signal that biologists can log, compare, and use for decisions.

That is how a park’s identity grows, not by erasing the past, but by adding tested observations. Science thrives on careful description, and this work adds a clear chapter to India’s evergreen forests.

The study is published in Insect Systematics & Evolution.

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