Jussi Murtosaari / Downy emerald (Cordulia aenea), male, Finland, June.

Jussi Murtosaari / Northern emerald (Somatochlora arctica), male, Finland, July.

Jussi Murtosaari / Downy emerald (Cordulia aenea) in flight, Joutsa, Finland, July.

Jussi Murtosaari / Downy Emerald dragonfly (Cordulia aenea) resting, southern Finland, May.

Jussi Murtosaari / Downy Emerald dragonfly (Cordulia aenea) in flight, South Karelia, southern Finland, June.

Danny Green / Downy emerald dragonfly (Cordulia aenea) male resting on twig with lichen, Glen Affric, Scotland, July . Bookplate from Danny Green's 'The Long Journey North'

Colin Varndell / Female Downy Emerald dragonfly (Cordulia aenia) at rest on flowering Gorse (Ulex europaeus) Higher Hyde Heath, Dorset, UK. April

Robert Thompson / Downy emerald dragonfly (Cordulia aenea) on fern, Killarney National Park, County Kerry, Republic of Ireland, July

Stephen Dalton / Downy emerald dragonfly {Cordulia aenea} in flight, UK

Steve Knell / Downy emerald dragonfly (Cordulia aenea) on lichen-covered twig, UK

Steve Knell / Downy emerald dragonfly (Cordulia aenea) on lichen-covered twig, UK

Steve Knell / Downy emerald dragonfly (Cordulia aenea) on lichen-covered twig, UK

Steve Knell / Downy emerald dragonfly (Cordulia aenea) on lichen-covered twig, UK

Colin Varndell / Downy emerald dragonfly {Cordulia aenea} male on bracken, UK.

Colin Varndell / Downy emerald dragonfly {Cordulia aenea} male. UK.

Steve Knell / Downy emerald dragonfly on heather {Cordulia aenea} Scotland, UK

Steve Knell / Downy emerald dragonfly on heather {Cordulia aenea} Scotland, UK

Konrad Wothe / Downy emerald dragonfly (Cordulia aenea) Cordulia arena, Upper Bavaria, Germany. May.

Danny Green / Downy Emerald (Cordulia aenea) male. Glen Affric, Scotland, July.