Saturday, May 10, 2014

Painted Lady migration

There have been numerous reports of Painted Ladies (Vanessa cardui) making their way north through Washington the past couple weeks.  The Painted Lady usually can't survive our winters and must migrate here from warmer regions in the southern states.  Depending on weather and population conditions, some years we may never see any Painted Ladies here, while other years they will be everywhere.  I haven't seen very many at all for the past couple years, but this year have already spotted two near Longview, and others have spotted them in places around Seattle, Ellensburg, and Spokane.  They are very fast and wary butterflies, often hard to catch or photograph.  Their larvae feed on thistles, so keep an eye out for spiny, lavender-gray caterpillars and shiny gold chrysalids whenever you see a patch of thistles!
Painted Lady Vanessa cardui - dorsal side
Painted Lady Vanessa cardui - ventral side
A cousin of the Painted Lady, the Red Admiral (Vanessa atalanta), is another butterfly that usually cannot survive our winters and must migrate here from warmer climates, although occasionally a lucky few will survive in garages or other protected areas.  Their larvae feed on stinging nettle, and form folded-leaf tents that I have described in a previous blog post (see here).  Red Admirals have been spotted near Yakima recently.
Red Admiral Vanessa atalanta - dorsal side

Red Admiral Vanessa atalanta - ventral side