Cicada Summer

A cicada

An edited version of this post appeared as ‘A summer of shrieking cicadas’ an article for ‘Rooting For Nature,’ my monthly column in Deccan Herald. The published column is linked here.

Over the last four years, Navilu Kaadu has roused our senses to nature’s rhythm. We are learning to recognize the sights, sounds and certain special visitors that herald new seasons. One such visitor marks the onset of summer.

Early this April, the motor starter of our irrigation pump threw in the towel while we were in Bengaluru. So, our first task when we reached Navilu Kaadu a week later, was getting the starter back in working order.

Later that afternoon, I sat on the bench by the cottage on a blistering summer’s day chatting with Chinnamma and Subbiah while they prepared Jeevamrutha, the microbial culture of good soil bacteria that sustains our crops.

A loud, high-pitched chirping interrupted our chatter. I recognized the ear-splitting racket from the previous summer — the song (or should I say shriek!) of the Cicada. I temporarily suspended my banter with Chinnamma and Subbiah, bolted from the bench and followed the commotion to a teak tree behind the withered remnants of the once grand Shami tree.  

Scanning the bole of the teak tree, I spotted the stocky harbinger of summer right away. The fellow was causing quite a din, proclaiming how desirable he was to all the girl cicadas around. Contrary to human cliches, the males are the source of hubbub in the cicada world while the females make nary a sound!

The cicada

Same time last year, I had sighted swarms of trilling cicadas on the thorny acacia trees and hoped to see the congregation this year too. Grabbing hold of my camera, I set out to inspect the acacia along the pathway running down the middle of Navilu Kaadu.

Sure enough, the tree pulsated with the plangent hum of a throng of cicadas, surging and receding rhythmically, drowning out every other performer in the Navilu Kaadu orchestra.

The lifecycle

Every summer as the mercury soars, mature nymphs or the young of the cicadas dig their way out of the earth after spending an entire year or two burrowing and feeding on liquid from plant roots in the subterranean world.

The newly emerged nymphs climb up trees, shed their exoskeleton and emerge as mature adults with protruding eyes and transparent wings, ready to mate and procreate. The male cicadas commence their legendary serenading to draw females and outshriek rival males.

A pair of cicadas on an acacia tree
A pair of cicadas on an acacia tree

How do they pull this off without vocal cords? Cicadas are virtually live musical instruments with anatomies designed to make and amplify psychedelic music!

The males vibrate ridged membranes called ‘tymbals’ on either side of the abdomen to produce stridulous high-frequency clicks. Their hollow abdomens, much like the hollow resonating body of the Indian veena or guitar, augment the sound of the tymbals.

If the serenading is any good, the lady conveys her approval with a flick of her wing tips and the pair mate. Soon the female lays up to 400 fertilized rice grain-like eggs over a period of a month, in slits she carves on slender branches with her ovipositor (egg laying apparatus at the tip of the abdomen).

The young hatch after six to seven weeks and feed on the tree sap. They resemble tiny termites or ants. The cicada hatchlings drift to the ground and burrow into the soil, build a chamber, and develop feeding on juices from plant and tree roots until they are ready to emerge the following summer to live out their short adult lives on the surface.

A cicada on a glyricidia tree

Most Indian species are annual cicadas, and the mature nymphs emerge once a year, while the periodical cicadas in North America emerge once every 17 years.

Cicadas spend their entire lives as nymphs underground but for the two-to-four-week adult phase, when they emerge from the earth to procreate and perish. It is this spectacular cycle of appearing and vanishing from and into the depths of the earth that has fascinated human civilizations across millennia and transformed the humble cicada into a powerful symbol of resurrection, rebirth and immortality, especially among the ancient Greek and Chinese.

Cicadas help prune weak tree branches when the females slit twigs to lay eggs, their burrowing action aerates the soil, and they infuse a burst of energy when they emerge even as they offer a delectable feast for birds, squirrels, lizards, snakes and more. In death, the cicadas return their nutrient-rich bodies to the earth, serving as a valuable source of nitrogen to plants and trees that once fed and nourished them, and life comes full circle.

Nothing ever goes waste in nature unlike in the human world, where nothing stays in use for too long before entering the waste stream and making its way to overflowing landfills or chocking waterways for an eternity. Of what use at all are we humans in life and in death?