I had 4 mid-september supersedures amongst my colonies last year. In each case the mother queen disappeared presumed killed. One queen didn't get mated and was found to be a drone layer in spring and one of the other three died out in february with plenty of stores but with no evidence of brood at all. The other two were fine and did well this year. Interestingly one of those didn't produce any brood before winter ( and I feared the worst) but was laying well when checked in early spring.
