NATURE Dainty damsels form colourful links in the chain

PRETTY PREDATORS?Damselflies snatch smaller insects mid air, scooping them into a basket formed by crossing their legs.

Dainty damsels form colourful links in the chain


Country Sights and Sounds 
John Shelley  

These are the dog days, when all we want to do is sit back and soak up the summer sun, and find somewhere to cool off once that has been done, while all around is the heavy, heady drone of a hardworking insect army, gleaning what it can and pollinating where it must be done.
The neighbour of a faraway friend (it is good to remove these things from one’s own doorstep) has taken it upon himself to de-vegetise extensively around his home and has succeeded in eliminating all those nasty wild flowers that must have been threatening him from their two-hundred yards of roadway, doing the deed with a noxious chemical mix delivered through one of those knapsack sprayers and making a valuable contribution to the efforts of mankind to eradicate honeybees and bumblebees, along with so many other things that keep our world ticking over.
Enough sarcasm for one day! We spent a happy hour (or could it have been two?) chasing slender, long-legged damsels along the lake shore and finding great amusement in the ease with which they avoided our intentions. They would watch with big round eyes and sit motionless until we were close, only to speed away the moment the hand was ready to grasp. Nor would it have been fair to have effected a capture. Being slightly built and delicate they would be easily bruised – and they, too, although so very numerous, surely play their own role in the great scheme of things.
After some searching we found one drowned and were able to examine the hairy legs and bulging thorax with a hand lens, noting the cleverly jointed limbs, the interlocking, brightly coloured plates that protect the vital organs and the miniature, shear-like mouthparts that so efficiently dismember the damsel’s prey.
I ought probably to clarify that these are flies – damselflies, beautiful and deadly predators of smaller insects, which they adroitly snatch from mid air, scooping them from the day with a basket formed by crossing their six legs. The stout hairs along each leg serve to make the mesh smaller and the snare more efficient. Anything taken in that deadly embrace is manhandled by six agile feet and delivered to those dreadful mandibles to be shredded, even while still kicking and, I imagine, screaming in its own mini-beast way.
And yet they are so prettily painted with enamel-bright blacks and blues, some metallic green, others ruddy ochre, each of them a fantastically formed aeronautic marvel.
We watched them hunting over beds of wild mint and through tall stems of fragrant meadowsweet and pungent agrimony, where their prey abounds. Sometimes there was a chase, with the intended target somehow aware of the threat at its tail. Not every hunt was successful; in fact, not half of them were, and more often than not the marauder would return to its favourite stem to rest and sun itself awhile, gathering strength for the next foray. They brought to mind the pressgangs that prowled Plymouth Hoe and other coastal towns in times long past to snatch a prey of men for pirate crews and military bands.
The damselfly has another role to play. Besides being a bandit of consummate skill it is also something of a delicacy for its larger relatives in the dragonfly tribe. Dragonflies have all the attributes of the damselfly but on a much grander scale. Remarkably agile in flight, they possess extraordinary manoeuvrability. They are the wolfhound to the damselfly whippet. Their jaws are quick to devour their lesser cousins, inflicting on them a terrible end even as those did before.
There is one more important role played by our damsel, one that the trout angler, if he is careful, can benefit from. After mating, the female damsels return to the water to lay their eggs, which they do in a variety of ways. Just once or twice a year they are found in sufficient numbers to interest the fish, which quickly gather into shoals to hunt the insects down. Then, if I have the day, I shall be there to set cold steel to the jaw of the trout and pull it writhing from its element. There might be an hour or an afternoon, or perhaps two together.
Does that make me as bad as the damselfly? The trout, left in the lake, would go to feed the pike and the pike has the reputation for eating its own offspring. Better the trout came home with me and the pike kept its own numbers down. In the end we all rely on those flying things that we mostly ignore. Go easy on the chemicals.