did you get the oothecae on ebay, i bought what they called stagmomantis carolina oothecae from them and the nymphs turned out to be tenodera angustipennis. the nymphs just look very similar! quite long. you will know for sure if they have bright green eyes and a stripe going along the head.
though if they are carolina, just care for them as you would any other mantid. feed them, hydrate them, give them space to molt, mist them.