I think it's very rare; I've seen it twice in 4 years of keeping tens of thousands of roaches, once in Byrsotria sp. "Cuba" and once in Blaptica dubia. Most likely, it is infertile, however, you could test whether or not this is true by allowing it to be breed with an adult male or a virgin adult female.I hope it isAnyone know where I can find more info on this? Im curious about how often they occur, if it could breed, if all are half male half female.