Nature Notes

By Denis O’Connor

Wharfedale Naturalists Society

(wharfedale-nats.org.uk)

ON SUNNY summer mornings I scan the vegetation poking above the surface of our four garden ponds, searching for the body shells of dragonflies that have emerged overnight to complete their miracle of transition from a dark watery habitat to an aerial one.

In the case of the large hawker dragonflies, they may have spent several years moving slowly among the pond plants, making sudden darts to ambush smaller prey.

As they grow, the larvae – smaller versions of the adults right down to embryo wings over their backs – split and discard their hard armoured body shells until, in their final stage, they climb from the pond up a plant stem or leaf, grip it firmly then split their body shells one last time (pictured is a recently emerged southern hawker).

The adults then cling to the old skins while their bodies straighten and wings expand, a process that can take several hours and during which they are at their most vulnerable. They then take to the air, their fast, zooming, erratic flight in total contrast to their previous gloomy underwater existence.

From our ponds the first damselflies – smaller relatives of the dragonflies – emerge in April and May, brilliantly coloured large reds followed by azure damselflies. The larger dragonflies – ours are almost all multicoloured southern hawkers – begin to emerge in late June or a little later, as with this year when we have had fewer sunny days. They leave the ponds to patrol nearby woods and gardens, returning occasionally to hunt over the water, at times approaching to hover unnervingly in front of human intruders. In September, the females return to lay eggs in vegetation above the water’s edge.

Also in late summer, bright red common darter dragonflies, smaller than hawkers, visit the ponds, the females dipping their abdomens into the water surface to lay eggs on water plants while gripped in tandem by males hovering above them. The darters seem almost oblivious to humans and, while sitting quietly, I have had them settle on my foot, my knee and even on my hat.

Other dragon and damselflies are occasional visitors to our garden – brown hawkers with amber wings, broad-bodied chasers with bodies like big blue bees, once a four-spotted chaser, a few migrant hawkers in late summer and now and again a banded demoiselle, the largest of our damselflies, wandering up from the Wharfe where they are common along the banks.

The summer presence of these fascinating, colourful insects is just one good reason for having a garden pond.