...in fact, I'll bet few of us ever have...none for me...
Wow and wow...Jim Easton found and photographed another amazing local sight in James City County on August 21st. This Eastern Tiger Swallowtail looked at first to be a very rare bilateral gynandromorph, containing both male and female characteristics. The condition is most frequently seen in organisms that show marked differences between males and females. Eastern Tiger females in their yellow form show more blue in the hindwing than males which are yellow, but females can also occur in a dark form, as in this photo. So...it looked like half male and half dark female.
But...wait a minute...there's a small blue spot on the forewing on the yellow side, which is shown in yellow females, but not males. The yellow side hindwing is missing.
So...it's apparently a female showing both yellow and dark forms...quite remarkable.
Thanks to local colleague Ken Lorenzen for forwarding the term "bilateral same-sex mosaic morph"!
An "event" in mitosis during early development is the cause of such conditions.
Brian Taber
