Imagine a wedding proposal by a groom with a loud monotonic message of love, would she accept him? Yes, if he was a Cicada! He has crawled out of his gown from the last nymphood and stood up on the dais of a tree trunk for his once-in-a-lifetime event. This event is timed particularly in summer when he along with a million others of his kind assemble within a few acres of such wedding halls to sing their love song.
Cicadas have contested among the loudest insects and won the title by reaching over 105 decibels in some species. Most singing congregations are formed by one species. One such was of Platypleura species’ that have brilliant black hind-wings veined with striking red bases. These Cicadas aren’t louder than the less numbered Platypleura basialba which too have beautiful wing patterns and greenish wash to their body. Although they sing together here in Satpura, they may have different frequencies to their choir.
Unlike crickets that rub their body parts to produce their song, Cicadas use special instruments called timbal in their abdomen, these are like the metal clickers we made a racket out of as kids at any conversation. Had you clicked it 400 times a second your first girlfriend would have been a Cicada! Perhaps she will find another Cicada whose timbal buckles the muscles in and out at 400 buckles per second. This is amplified tenfold on ribbed timble plate to compose the love song. This song resonates in an air cavity in their abdomens to send the message to their love bug. Such messages are whined by millions of male Cicadas putting a passing tractor’s noise to shame.
In such numbers there is safety by giving predators a satiation, especially to Indian Rollers, Drongos and Shrikes who are known to make use of such abundance. A few would be persecuted by Garden lizards, agamas, wasps and spiders who wait for this bounty. The periodic Cicadas that emerge once in 13 or 17 years are Magicicadas of North America. This emergence could deregister any predator’s memory of anticipation. However most Cicadas emerge once in 2 to 6 years.
Here in Satpura, Platypleura sp may emerge and when they do, these true-bugs molt a few feet above on plants. Either for defense or for alarm they squirt the sap liquid from their anus when anyone passes near their ceremonial gathering. Trust me it is tasteless.
Interestingly the Cicadas’ highest assemblage were on bright barked trees like Axle wood, Dhobin, and Kadam trees. We sung into scientists’ ears if this is a strategy employed by grooms to stick out of camouflage and present themselves for the lady Cicada or is it an association with specific tree sap or would pale bark aid the hot-blooded Cicada to regulate their body temperature during their musical sessions.
As adults the Cicadas suck the tree sap using a hard straw from the choice of trees. But females have another straw at their rear to deposit her rice grain like eggs into tree barks by slitting. The song must be heard in a day or two to mate successfully and rest in peace forever. The eggs hatch in the slits made by their mother and feeds their first meal of sap liquid in that groove. Then they drown under the ground up to 8 feet and feed on the pipelines of trees for minerals and water. Here they develop through several stages of nymphood for the next 2 to 17 years depending on the species. And then comes one summer, and that particular day for a male imago to cast his gown and sing that very groom’s song of love.
As the summer Sun warms the land it defoliates trees and triggers them to flower. And this colorful and fragrant drinking fest attracts millions from beetles to butterflies and Starlings to Giant Squirrels, most of the entrepreneurship is taken by bees. Rock bees swarm looking for ridges, tall trees, steep and high rocks to hive. They start colonies wherever they find such ledges and water nearby. Such a spot was an entrance to a cottage at Forsyth Lodge!
Deepanker the manager had to act quickly before the guests arrive and before the bees hem their wax into a comb. After an inspection he came to the naturalists with a news of another entrepreneur around the bees.
‘It is a large moth you guys must have a look’ he cried.
This moth had perched behind the lampshade right behind the colony. We could only see it partly and we peered to have a look after negotiating the enquiring worker bees. But the shadow behind the lampshade only threw its largeness and rusty wing overall. After investing on the risk of getting past an active and aggressive rock bee colony, we were determined to find what the moth was upto. We gently tapped the abdomen for it to crawl outside but the moth turned out to be a death-trap to Deep and me! It squeaked and dashed into bees, then it flew at a great speed hysterically and disappered. Deep had exited the passage by then looking for the moth. And I had pushed myself into the wall’s plaster under the lamp and closed my eyes tight. Half-a-minute later it all appeared to be real and I peeled off the plaster and walked out surreptitiously with a prized moth perched on my shoulder!
Death-trap was set to prove the myths of Death-head moth. This smallest of the three Acherontia moths had chosen the lampshade. This is styx species and a Death-head is a name for its skull like pattern on its thorax. Some say it is to deter any attacker and some say it mimics worker bees, but Buffalo Bill makes it ghoulish in the movie The Silence of the Lambs.
‘Bro this BBC’s post says that they feed on the honey Bro’ exclaimed Bejoy reading about Death-heads in his uncanny naturalist’s enthusiasm. We piled on to read about this snatching the screen away from him. The Death-head moths are known to savour honey from median bees of Europe. It is also said that they make squeaking noise around the hives. And Heinrich Prell who unraveled this in German in 1920 went unnoticed by English readers, he writes about its fondness for honey probing with a short proboscis. He also had decapitated a death-head to find where and how it makes the deathly squeaks. He finds that the moth has its pharynx adapted to inflate-deflate instead of clicking like Erebid moths or any other moths that make sounds from their bodily adaptations.
As the fascination grew about this beautiful moth, of its myths and its physics, I stumbled upon recent discoveries on its chemical capabilities too. That they can mimic the scent of the bees and feel at-home from defensive workers to feast on their honey! Isn’t this a heist entrepreneurship of one insect over several armed entrepreneurs in the heat of summer that work as one?
What has this Acherontia moth got to do with squeaking sounds which we too heard while setting it back on lampshade is still unclear. Could it just be a defense? Is it in the bees’ vocabulary? Another question that squeaked to me is what motivates a moth to feed on honey- a protein rich sugar? We now are following the Death-head moth’s life-cycle and following bees for their marvellous predators.