Thronging streams and lakes now are several species of damselfly, the largest of which is the magnificent banded demoiselle, my favourite insect.

The body of the male (pictured) is a metallic bluish-green and his wings carry very distinctive dark blue bands, whereas the female's body is a shimmering green tinged with bronze but her wings are a clear greenish without the blue bands.

They can be seen in groups flying with slow fluttering flight just above the water or perching on bank side vegetation.

When perched, males use their colourful wings rather like signal flags, flicking them open every few seconds in a kind of semaphore to advertise territories or attract mates.

After mating, the male guards the female while she lays eggs into water plants, usually under the surface and she may even completely submerge, being able to breathe because she traps a layer of air between her wings.

There is a similar but much scarcer species, namely so called beautiful demoiselle.

The wings of the male are bluish- black and lack the blue bands of the banded demoiselle.

Both species prefer slow -flowing streams or rivers but can occasionally be found in lakes if they are fed by streams.

They are both certainly worth searching for.