That would be due to sex linking. In humans there is either XX or XY and some genetic issues are only carried by the Y chromosome meaning only men can carry it, ect. This isn't a case of sex linking but there is a possibility that there could be a defect during mitosis like the spider gene causing it to not split properly or later when the DNA copies for meiosis. It could also be during DNA crossover. I wish someone would take samples and replicate the process in a lab so we can know for sure Btw my clutch of lesser bee X killer bee has pipped![]()