Photo of the Week

Male Blue Dasher
Male Blue Dasher
Pachydiplax longipennis, Libellulidae
Grant Narrows, Pitt Meadows, British Columbia, Canada
Nikon D5100, 70-300 mm f/4.5-5.6
July 13, 2013

This week we return again to Grant Narrows. I took another trip out there last Saturday and I was able to photograph some more dragonflies. This Dasher was yet another new species of dragonfly for me. Grant Narrows seems to have a very impressive Odonate fauna. The pale blueish coloration of this dragonfly’s abdomen is know as pruinescence. This blueish coloration is a type of structural coloration caused by minute particles of wax on the outer surface of the cuticle. These wax particles scatter light preventing it from interacting with the pigments in the cuticle. The blueish colour is due to the Tyndall effect in which shorter wavelengths are scatter at a greater intensity. If you have devastatingly blue eyes like myself you owe this colour to this effect. The wonders of the fantastic counterintuitive world of optics.

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