Bio-Montagne - Réseau d'éducation sur la biodiversité dans les zones alpines - Programma di cooperazione transfrontaliera Italia-Svizzera 2007-2013

Aeshna grandis (Linnaeus, 1758) Brown hawker

Family: Aeshnidae

This dragonfly is easily recognized by its distinctive appearance, in particular its large size:

70-77 mm in length and 80-98 mm wingspan.

The body is a tobacco-brown color,

the wings are bronzed and it has

yellow lateral stripes on its thorax.

There are yellow spots on the

female's abdomen and blue on the

male.

Like all dragonflies, when landed,

the wings are held open and in a

horizontal position.

It flies from the end of June to the

beginning of October, preferring

natural Alpine lakes at medium to

high altitudes with a large amount of aquatic vegetation.

The brown hawker is exceptionally skilled in flight, and is capable of sudden spurts of

speed in very small spaces or changes of direction, flying vertically, sideways or backwards

and hovering. Its prey, including mosquitoes, flies and other winged insects, are caught in

flight, thanks to the hawker's wide visual spectrum gained by rotating its head by up to 180°

and using its enormous semi-spherical eyes.

The eggs are laid just underneath the surface of the water or on floating plants. The larvae

are grey, similar to tiny shrimp, but already displaying large eyes on a mobile head like the

adults. When fully developed they leave the water, climb onto the stems of waterside

plants and wait to undergo the profound changes that will allow them to live on land.

While very common in central and Eastern Europe, the species is rare in Italy and found

only in Aosta Valley, Alto Adige and Friuli.

(Photo MRSN)