Arctic Blue - Plebejus glandon

Another interesting little butterfly that can be found on the Sinlahekin Wildlife Area is the Arctic Blue, Plebejus glandon.  They were first discovered there in 2006 by another butterfly surveyor, at approximately 2600' elevation.  This was a record low elevation in Washington for this species that is usually only found above 5000'.  In 2008 I found another one about a mile down the road at 2400' elevation, and this year I found these two (photos below) at the same location as the original sighting in 2006.  So far we have only seen males, but we believe the females must be high up in the rocky slope above the road, close to their hostplant which is also yet to be confirmed.  Larvae of this species are known to feed on plants in the Saxifrage family, but without climbing the nearly vertical rock slope, it will be very difficult to determine exactly where these butterflies are coming from and what they use as their larval host.

Arctic Blue Plebejus glandon - males, dorsal and ventral