Hmmm, im not sure you really need to transfer any just yet.
Is there not some food supply in with them now? If there is, then that should be enough to keep them going. Once you have your first flies appear... wait a couple of days (I heard one of the sexes has i quicker hatch rate)... when you have what looks like 50 or so move them to the new culture, they will breed and start a new batch for you
I've had to do this a lot, I keep Mantids as well