Over several decades, James R. "Jim" Neidhoefer, a local businessman with a passion for butterflies and moths, donated his collection of more than 100,000 specimens plus several hundred volumes of rare books and monographs on Lepidoptera.
Within this extensive collection are several hundred gynandromorphs, aberrant forms showing male characteristics on one side of the body and female on the other, and sexual mosaics, displaying mixed female and male characteristics. Gynandromorphism in particular is a rare condition that occurs in perhaps 1 in 50,000 moths and butterflies. The result is an error involving the sex chromosomes in the first cell division and the butterfly or moth is born sterile.
The photo shows Phoebis argante, a Sulfur butterfly (from Santa Catarina, Brazil). The bilaterial gynandromorph is shown between a normal male (left) and female (right) of the same species.
Thanks to Mr. Neidhoefer's donation, the Milwaukee Public Museum houses one of the largest and most extensive collections of these gynandromorphs in the world.
