Bilateral Gynandromorph of the Regal Fritillary

We have been having great success in the lab with our Regal Fritillaries. More on that soon. Today we got quite a surprise from a Regal that just emerged from its chrysalis. Regal Fritillaries are sexually dimorphic. There are two rows of spots on the upper surface of the hindwings. In the males, the outer row is orange. In females, both rows are white.

The right half of the individual in this picture is male and the left half is female. The shapes of the two hindwings are subtly different. Even the body is split in half this way- the right half has a single male clasper. Bilateral gyandromorphy, while rare, is not unheard of in butterflies. It probably goes unnoticed (at least by people) most of the time, because when the males and females share the same color pattern, the effect is quite subtle. This individual is likely sterile- unfortunate when you are trying to rear as many adults as possible in order to establish a new population.