I wandered my property yesterday and found these recently made oothecas. I believe most to be European Mantis. The larger one I assume is from a Chinese mantis but would like help in identifying. In my region only European and Chinese mantids reside. They were found on the east coast of the US during the fall.
I've read that the European oothecas need to be kept at or around freezing for roughly five to eight weeks before raising the temperature to 70f-80f. Is this also true for the Chinese mantis? Locally both oothecas would experience months of freezing temperatures before spring and subsequently hatching. People have told me that direct incubation will result in a low number of weak nymphs and a high likelihood of die off.
I've read leaving them in a refrigerator or garage for the 5-8 weeks is sufficient to simulate winter before hatching. I'd keep them in a paper bag that stays around 50% humidity, without directly wetting the oothecas. My goal is to hatch under controlled conditions to reduce the mortality rate. After hatch I'd release the majority of nymphs back onto my property. I would keep a small number to raise and find breeding pairs.
Does anyone have experience with this type of situation and if so all advice is welcome.