Family: Aeshnidae
Scientific name: Anax imperator Leach, 1815
English common name: Emperor or Blue Emperor
Spanish common name: La libélula emperador

Portuguese common name: Libelinha (not sure of common name)

Total length: 66 to 84mm
Hind Wing length: 42 to 52mm
Altitude: Sea level to 1500m+
Flight period in Iberia: late April to late October
Habitat: Open water with plentiful emergent vegetation around ponds, rivers & lakes.
Distribution: Europe, Western Asia, Africa & the Middle East. Widely distributed throughout the Iberian Peninsula.
Similar species: Lesser Emperor – Anax parthenope & Green Darner – Anax junius (a very rare migrant from North America first recorded in 1998).

One of the largest resident dragonflies on the Iberian Peninsula, it is both fast flying and highly territorial and as such is seldom seen at rest. A large pond or stretch of river may only support one male who will tirelessly patrol his patch of water, promptly seeing off any intruders with a fierce clash of wings.

The male has a strikingly blue abdomen which when in flight has a slightly downward curve, giving a bent appearance, a useful feature for separating the restless Emperor from the other hawker type dragonflies whose abdomens generally appear straight. The blue green eyes & green thorax make this a very handsome insect.

The female is generally green in appearance with dark markings along the centre of the abdomen. They oviposit alone into floating vegetation or submerged plant stems, a feature which helps to separate this species from the Lesser Emperor – Anax parthenope which generally oviposits in tandem.

The larval stage of the Emperor may last from one to two years before emerging as an adult on reeds or rushes around the margins of their chosen water body. The cast skin or exuvia can be found long after this spectacular transformation takes place and is an exact replica of the larvae which can be identified to species level. Collecting these exuviae can give an excellent indication of the true population size at a site and is conclusive proof of successful breeding.

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