Tuesday, August 12, 2014

A Forcipate Emerald at the Stoco Fen

Reputed to be rare and local, perhaps the Forcipate Emerald is more common than generally thought and is merely secretive, with a preference for habitats that are inaccessible to the average person, such as bogs and alder swamps – or the Stoco Fen.

Somatochlora forcipata is a medium sized dragonfly with a length of 45 mm to 50 mm. It flies from early June until mid-August and this male, encountered on August 11th, is beginning to show its age and its few yellow markings are obscured.

One thing time doesn't fade in an Emerald are its eyes. In fact, they start out life as rather dull orbs, and acquire the luminous green that seems to glow with an inner light only with increasing maturity.

The abdomen is relatively slender.

Many Somatochlora spp – especially older dragonflies with dulled colors – resemble one another closely even when perching and have to be identified in the hand. Even so care must be taken because the terminalia of the Forcipate, Incurvate, Kennedy's and Delicate Emeralds look superficially similar to one another. Here's series of images making a 180° "walk-around" the claspers.

A few other unidentified Emeralds (including a possible Brush-tipped Emerald)and Darners were sighted at the fen, and it is currently host to a robust community of Band-winged Meadowhawks (Sympetrum semicinctum). Who knows what other odonate surprises might be lurking out there in this unique little corner of the world?