from the November 28, 2010 Newsletter issued from
Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
SEXUALLY DIMORPHIC BUTTERFLIES
I sent Bea what I thought was a new species of yellow butterfly, but she figured out that it was just the female of a species whose male already is represented on our famous Yucatan Butterfly Identification Page at http://www.backyardnature.net/yucatan/mariposa/.
We're talking about the Dina Yellow, PYRISITIA DINA.
You can compare the sexes -- the male on the left -- in the picture above.
Notice that although the male and female color patterns are strikingly different, the vein pattern is identical in both sexes. In insect identification it's nearly always the case that wing venation is much more important than color.