Contrary to what others on here have experienced, when my Chinese mantid ooths hatch I have a hard time feeding all the nymphs!I once had 3 ooths hatch at once (when I was in 5th grade; Now I'm in 12th) and so many lived to L2 that we had to start freezing them so I wouldn't be overwhelmed!
You may be doing something right that we are not, Zephyr, but I think that a number of us have had large numbers surviving past their first molt, though still an unaccountable number die, but by the time they're ready to molt to the next instar, numbers drop dramatically, possibly due to canibalism of molting nymphs at that age as well as "SIDS". There is a facile (I think) answer to this. It has been argued that a given environment in the field can only support a given biomass of mantids (or any other insect) and that as they grow, the number of individuals has to decrease to keep that mass stable. This theory, though, doesn't hold under what Superfreak has called "ideal" conditions. Our nymphs get as much food and moisture as they could possibly want, and yet dozens, hundreds perhaps, just drop dead.
It might just be that Hibiscusmile has the answer. In nature, the nymphs would scatter and hide and lead very quiet lives. Many would be predated, particularly by spiders at that age, but those that were not would lead a much "quieter" life than they do in our enclosures. It would be an interesting experiment to hatch a Chinese ooth in, say, a 1' (30cm) cube and remove about twelve and raise them as a seperate group in a similar sized cube to determine if the survival rate would be higher among the "chosen few" than among the larger population. My guess is that it would not be.
Another experiment if you are lucky enough to see the beginning iof a hatch would be to isolate the first dozen to emerge and see if that group had a higher rate of survival than the rest.
Now all we need is someone with time, patience, a few chinese ooths and a lot of cubes.....
