Tuesday, November 20, 2012

Stirring Up A Winter-flying Moth - A Surprise Sallow

We met this furry creature on the mountain top on Saturday.
 We think it could look like a rabbit with all its furriness and its big eyes. However, this is the face of a winter-flying moth.
   I think this is a Morrison's Sallow (Eupsilia morrisoni).  All that hair (its thoracic pile) helps retain the moth's body heat during flight. That insulating pile helps these Noctuid moths (owlet moths of the subfamily Cuculiinae) with their amazing ability to fly on mild winter days.
   What caught my attention with this particular moth, was seeing a moth flying so late in the fall when few other insects are flying.  I watched the moth fly through the woods and land about 15 ft. up in a tree.  Soon it flew down to the ground and landed on a lichen-encrusted rock, where I took the close-up photos above.
On this mid-November day, my boys and their cousins were messing about in the woods.  As I approached the boys to see what they were doing, I saw they were building some forts.
 They were disturbing the area slightly. In their messing about, they were stirring up the leaf litter. This disturbance brought the moth out of its hiding spot in the leaf litter just at the moment I was close enough to see it fly.
 I saw the moth fly up from the ground and head for the tree tops.
   Winter-flying moths like this sallow spend the winter hidden in the leaf litter.  They overwinter on the ground where the temperature hovers near freezing.  On mild winter days these moths can shiver to raise their body temperature in order to fly around to feed on sap leaking from tree wounds.  I've seen some  winter moths visiting a maple sap bucket.

I have previously posted about seeing flying moths in late November.

Read more about winter-flying moths and other amazing  thermoregulation feats in Bernd Heinrich's book...

1 comment:

  1. That first macro shot is wonderful Dana. I always enjoy tagging along and would be happy to help with the fort-making if needs be.