By MIKE GILLAM
Photo © Mike Gillam
Following the drought-breaking December rains, swarms of insects tunnelled to the surface after months of subterranean bondage. Birds sang in praise and the pores of the saturated earth opened.
Ant and termite alates emerged on the first and second days of the event, trusting on significant rainfall, critical to the establishment of new colonies and the practical ease of digging new nests.
Those of us who routinely look to the skies would have noticed the aggregations of kites and crows circling above invisible vortices of flying insects. Competitive crows always make their presence felt when food is in the air.
Flying ants and termites hardly seem worthy of a raptor’s attention, yet predatory kites expend little effort as they ride the thermals, snatching up the queens in their talons and devouring them on the wing.
I’ve taken thousands of images of insects flying blindly around lights, captured in their irresistible thrall, expending energy in a pointless whirling, a spinning dance of death that consumes billions. In my imagination these lights are weapons of mass destruction, ice pipes for insects, no less.
For the detached viewer, the images are as beautiful, hypnotic and poetic as any mass suicide can be. They fail however, to show the immense scale of the carnage, the unimaginable waste of biological potential. Hawk-moths, the promise of future generations of Yeperenye caterpillars, are frequently among the victims.
This awakens the anarchist in me and I suppress the urge to smash these false moons: to free the legions, allowing them to fulfil their life’s true purpose; to break out of the ground after a lengthy period of stasis, to smell the fresh rain, to fly into a starlit sky, to drink the nectar of the native passion-fruit, to strive all night until sunrise, to search out a mate, be chased by bats and prevail or not, to lay eggs and finally, their life force spent, to succumb to exhaustion and scavenging ants.
An existence that is short and frenetic, that’s true, yet their triumphant stories, their egg sites and ceremonial grounds are the subject of time honoured legends vibrating on the air and beneath our feet.
I’ve tried various techniques to convey the sheer volume and energy of this spectacle and settled on mercury vapor lights for their photographic advantages and the invertebrate hell they often create. If you look closely you will see that many of the moth shapes are arranged in sequences, recording the arc of each flying moth and its wing-beats exposed by the light during the length of the exposure.
Herein lies a clue to the lighting and shutter speed I selected for the image chosen for this week’s post. Mercury vapor lights flicker at a rate that ordinary mortals don’t notice. The shutter speed I selected was ¼ second and this has recorded the flight of individual moths at approximately 15-16 wing beats during the length of the exposure, the lighting provided not by a flash but by the rapidly flickering light source.
This suggests the mercury vapour light that proved so attractive to the cloud of flying insects swirling over an Alice Springs car yard was rated at 60 hertz. Conversely, if the viewer knew the hertz (cycles per second) of the light source I’d selected, they would be able to count the exposed wing beats and ascertain the shutter speed I’d used.
From street lights to car yards and suburban porches, we use bright night lighting with complete disregard for its destructive effects on urban wildlife. Do we really need to leave that verandah light on all and every night so that potential burglars can better see what they’re doing in the rare event they actually choose to intrude?
Town lighting sucks insects from the surrounding bush, from the river, the foothills and the mountains, in numbers so vast they can only be imagined in the tonnages.
Next morning, we spray the ant swarms and the prowling Irlperenye (stink or green tiger beetles) attracted to the dead and dying insects in the mall, the atriums of luxury hotels and shopping centres. Car yards must also believe it’s worth the effort to use high intensity lighting to illuminate their cars for perfect night viewing by prospective buyers.
They certainly pay a high price of collateral damage in the mass of dead and dying insects that cover their sparkling Duco, much to the chagrin of the long suffering car detailer.
While it may not be perfect for showing off products, yellow lighting is the friendliest option by far, the colour that interferes least of all with the behaviour of nocturnal insects and a time saver when it comes to managing the collateral damage or ‘pests.’
Yellow LEDs that fit bayonet or screw mounts must surely be available locally, at all good lighting suppliers.
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