Published:October 1, 2017 12:10 am
If you have a passion for watching dogfights a la the Battle of Britain, this is the time to take yourself to the nearest water body — a pond, lake, river, stream or even alongside a shiny strip of tarmac — and watch dragonflies. If you’re up early, before the sun is warm, you might find them perched on stalks, stems and branches, their gossamer wings stained with their species’ colours, waiting patiently. Once the sun warms their engines — two pairs of mighty flight muscles located vertically in their thorax — the four wings, flimsy as cellophane, begin to whir and blur; and the insect lifts off in the blink of an eye. One pair of flight muscles controls the downstroke of the wings, the other, the upstroke. Each wing can beat independently — or even stop beating completely, allowing the insect to jink, dunk and flick upwards, downwards and sideways at full throttle. The wings, in fact, start beating the moment the insect’s six spiky legs lift off their perch.
Once airborne, the aerial combatant, considered to be the first insect to fly (they have been doing it for over 300 million years, so they have clocked plenty of flying hours), chalks out a territory — a corridor in the sky — and patrols it assiduously. Enter its airspace at your own peril — it will not hesitate to charge you. You might laugh at its gumption — at most, its wingspan may be 20 cm, but if you had been around 150 million years ago, you might have turned tail and fled — because the dragons of yore had wingspans of almost one meter. It’s also comforting to know that dragonflies neither bite nor sting. It would, of course, be an entirely different story if you were a bee, wasp, fly, a flying cockroach, butterfly or even another dragonfly. As you blunder into the sacred airspace, you will immediately come under the surveillance of powerful eyes. Your shape and movements will be established and tracked by two kinds of specialist lenses — maybe 28,000 of them in all — so there’s no getting away (except if the insect has to change its contacts at that time!) Suddenly, you get rear-ended by something traveling at maybe 90 kmph, the impact of which will kill you outright. If you do survive, it’s probably worse. You’d be scooped up and clutched close in a barbed gin trap of a basket (the dragonfly’s six legs) and then quite simply, your head will be chomped off. You’ll be eaten on the wing, or taken to a stalk and consumed at leisure.
Ah, you may ask, if anything were to rear-end you at 90 kmph, surely it would be totaled too. The dragonfly’s “fuselage” however, consists of segments that are arranged diagonally in order to absorb the energy of the impact. Pinpoint orientation and stability in flight is provided by fine hairs on the joints of the neck. And, even though the insect can glide for long periods, its wings held stationary, it needs large amounts of energy to fuel its aerial lifestyle. It can get through its own bodyweight in food in just half an hour and one champion was documented eating 40 flies in two hours. Apart from hunting, what the dragons are looking out for are, of course, lady dragons. No, not damsels, which is another story altogether.
The male dragonfly, alas, is a complete boor: if a suitable lady enters his territory, he first transfers packets of sperm from his nether end to special sperm bags in the front of his abdomen. Then he hovers in front of her, his wings shimmering, before simply grabbing her roughly by the scruff of her neck (often doing real damage) with special claspers on the tip of his abdomen. With her firmly hitched, he flies off with her in tandem. She curls the tip of her abdomen into his sperm “sky bag”, completing the evocative heart shaped daisy wheel we get so gooey eyed about. She’ll fly down now, to lay her eggs under water, stuck to the stalk of an aquatic plant or the underside of a leaf, or just scattered on the surface — with him in close attendance. Not so much out of gallantry but to make sure she doesn’t get up to any mischief with another gentleman and thus ensuring her progeny carries only his genes.
And what progeny! They’re called “nymphs” or “naiads” but really are submarine bottom-dwelling horrors that will terrorise small fish, tadpoles and other small aquatic life forms for the next two or three years. They breathe through gills in their rectums and use the same to give themselves jet-propelled enemas in order to get around. They have bulging gargoyle eyes, and dreadfully outsized and hooked lower jaws which flick out, snaring a passing tadpole and dragging it back into the mouth. They will molt 10 or 15 times in the years that they’re underwater, before finally emerging, to crawl up a stalk, weak and etiolated, to finally transform into a full-fledged dragonfly.
Of course, it’s not all smooth sailing: birds like bee-eaters and roller jays will actively hunt dragonflies, snapping them out of the sky and bashing them to digestible mush before swallowing them. What goes around comes around.
There are 5,000 species of dragonfly worldwide, with around 500 in India — in gold, black, midnight blue, teal, pillar-box red, orange, yellow and myriad other shades. If you look low over the water, you may spot their ethereally invisible cousins — damselflies — in electric blue, neon green and other startling colours. They rest with their wings folded alongside their fuselages, not perpendicular, and keep a low profile for a very good reason.
The dragons will eat these damsels.
Ranjit Lal is an author, environmentalist and bird watcher.