Gynandromorph Monarch

Gynandromorphs are individuals having both male and female characteristics. The cause of this phenomenon is typically (but not always) an event during early development. While the organism contains only a few cells, one of the dividing cells does not split its sex chromosomes typically. This leads to one of the two cells having sex chromosomes that cause male development and the other cell having chromosomes that cause female development.

Here is a photo of a gynandromorph photographed by Heather Ness in the USA.

It is a halved gynandromorph; the butterfly is completely male on one side and completely female on the other.

It even shows one clasper on the male side of the body. Most gynandromorph specimens just show patches of the opposite sex in the wings and are not completely halved. Evidently it is very rare in monarchs to find something like this.