Sunday, March 25, 2012

Ladies and ladies

Bodega Head is generally a difficult place for butterflies — it's often cold and windy.  But when the sun is out and the wind is calm, if you search in sheltered locations you might encounter them.

On 25 March 2012, I noticed this butterfly basking on the ground at Doran Beach.


It's a West Coast Lady (Vanessa annabella), one of three ladies that may be seen in this area.  A couple of important field marks (highlighted below): all four of the hindwing spots have blue centers and the large spot on the leading edge of the forewing is orange.


In the other two species, the hindwing spots either don't have blue centers (Painted Lady, Vanessa cardui) or only two of them do (American Lady, Vanessa virginiensis).

In Painted Ladies and American Ladies, the large forewing spot on the leading edge of the forewing is usually white, or sometimes pale orange (paler than the rest of the orange on the forewing) — see next two photos.


This photo above was taken on 4 March 2012.  Note the colors of the forewing spot and the hindwing spots (red circles below), and that there is generally less black in the inner forewing (pink circle below).  

My best guess for this species is American Lady.  Most American Ladies also have a small white spot inside the orange on the forewing (see white arrow below).  It's missing in this individual, but that's a known variation, and everything else seems to fit for American Lady.  (Let me know if you have a different opinion!)


If you're interested, there's a checklist of butterflies seen at Point Reyes available on the National Park Service web site.

No comments:

Post a Comment