As temperatures start to climb at last, our dragon- and damselflies are at their most apparent, hunting above local ponds and rivers. . . .
These beautiful creatures with their electric colours and flashing wings are some of most spectacular creatures and also among our oldest residents: genuine living fossils, whose ancestors were here well before the first dinosaur.
Most people are unsure how to differentiate between damsel- and dragonflies. The former are the smaller and more lightly-built, with side–mounted eyes. Dragonflies, in contrast, are bigger and more robust, with a powerful flight (many emitting a menacing drone, reminiscent of a miniature bomber). They also have huge eyes which seem to occupy almost the entire head.
Both groups depend on water for their larval stages, usually spending up to three years submerged in a pond, stream or ditch. Here they are anything but beautiful. Indeed the creature in Alien might to have been modelled on a dragonfly nymph, both in looks and lifestyle for they are ferocious predators, hunting virtually any aquatic creature up to tadpoles and even adult newts.
Unusually for insects, the family has no pupal stage, but instead nymphs simply crawl out of the water where their cuticles split down the back, allowing the adult dragonfly to unfurl itself to dry in the sun. Within a few minutes their wings have hardened and their bodies begun to assume the bright plumage of their all too brief adult life. Even in ideal conditions they rarely survive more than a few weeks in their new airy world. As they patrol above the water, many fall prey to birds and bad weather is another killer. Nevertheless, they live life to full during their brief adulthood. At first they hunt actively, using their legs as a kind of basket to trap flying insects, while the males develop the full depth of the electric colours that are typical of so many of our 34 resident species. Meanwhile the females are building up reserves of protein from their insect prey with which to produce eggs.
This is when the males’ thoughts turn to sex and they begin to patrol ceaselessly near the water in the hope of ambushing a female. These are pounced on in flight, with the males using hook–like appendages at the end of their abdomens to grasp their mate. Locked together, the couple lands on a plant near the water where the female will lay her eggs.
Sadly, many species of dragonfly are threatened – not least because 75% of farm ponds have disappeared over the past century. They are also sedentary, so they find it difficult to recolonise lost ground. But habitat change creates new opportunities and species like the broad-bodied chaser have readily switched from village ponds to garden water features all along the Border. This gives all of us – but particularly children – the chance to don a diving mask and peer beneath the duckweed to investigate a miniature world where sci-fi horror meets the plains of the Serengeti.
