Recent butterfly (and moth!) sightings at Fermilab
Tom Peterson

July 16, 2008  
A long time since the last update, and there is some important news -- Gypsy Moths have arrived at Fermilab.  Male Gypsy Moths fly day and night.  During the day they look like small brown butterflies, but like most moths, their flight appears a bit more labored, without gliding.  The females are larger and white and do not fly, laying their eggs near the cocoon from which they emerged, typically on the trunk of the tree. 


Gypsy Moth
Gypsy Moth male at Fermilab, July 10

Gypsy Moth

Gypsy Moth female at Fermilab, July 10


Butterflies have been out in good numbers.  Gray Commas and Banded Hairstreaks seem abundant at the woods edge.  Common Wood-nymphs are flying in the fields and prairies.  It looks like a big year for Mourning Cloaks

Finally, a new species for the Fermilab site was spotted and photographed last week -- a Northern Oak Hairstreak.  It looks very much like a Banded Hairstreak (what's different:  orange cap on the blue spot, pattern of white lines on underside hind wing) and was flying in the same area, the western edge of the big woods.  We are at the northern edge of the range of this species.  Perhaps their range is extending north, a species to watch for here in future years. 
Oak Hairstreak

Northern Oak Hairstreak at Fermilab, July 11

April 7, 2008  
This past weekend marked the first warm weekend of the spring and the first local butterflies!  A short walk through the woods at Fermilab revealed many Eastern Commas (winter forms) and Mourning Cloaks.  Since these species overwinter as adults and become active with the first sunny, 60 F + days of the year, they are often the first butterflies that I see here.  The flashy presence of the orange commas resting on the brown leaves in the woods can be quite striking. 

Up to Butterflies of Fermilab



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