Treeline Emerald

Kohteesta Korentowiki
Loikkaa: valikkoon, hakuun

Treeline Emerald Somatochlora sahlbergi

The world's most northern dragonfly, Treeline Emerald is only found in the far north, well above arctic circle.

Small, dark and hairy emerald. Males resemble Alpine Emerald, but the anal appendages are very curved. Long and pale pterostigma. Female difficult to separate from Alpine females - pterostigma is longer and pale orange, and vulvar scale is short, low and clearly notched at the apex.

Uncommon, but apparently not as rare as the relatively few records might suggest - larvae have been found in many waterbodies in northern Utsjoki municipality. Poor weather and short flight season combined with very irregular recording in Northern Lapland make this species as one of the worst known in the Europe.

Only found on Northern Utsjoki, from Karigasniemi to Kevo and Nuorgam. Favours small swamp lakes and ponds, with peatmoss. These ponds are usually deep and have emergent vegetation. Observed flight period is short, from July to August.

Somsah naar.JPG

Female. White ring at segment two is only shared with Alpine Emerald. There is also only one crossvein between base and triangle in the forewing. Janne Koskinen

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