Rob Byatt,
This is my last post in this thread.
The amount of experience I have raising mantids is not at issue here because I never tried to answer the valid question that desana asked. Christian's response was that any difference in mortality rate between mantid species is the fault of the breeder. After further discussion, it became clear that the only way mortality rates would be near equal is if breeders knew all about the special requirements of each species raised in captivity and continually maintained those requirements. That is academically or theoretically correct. But, in practice, not realistic. That's why there is variability in mortality rates amongst mantid species even when the breeders do nothing wrong based on current knowledge.
Now, we can discuss the fact that most breeders, even the best, are not perfect. Even if they know the ideal conditions for raising the mantids, the conditions will vary to some degree. The mantid species that are less affected by changes in conditions will have a lower mortality rate. Some species, for whatever reason, are just plain easier to raise than others. Just reading this forum and other forums that discuss mantid breeding makes that obvious. And not all of it because of bad breeders.
The bottom line here is that you have to look at the original question from a practical perspective and not from an academic perspective. Because that is how it was asked.
S-
P.S. In high school I raised a variety of insects, including mantids, for several years. My plan was to go into entomology or herpetology in college. While in high school, I worked two summers in the entomology department at Cal Tech (genetic research). I ended up in computer science instead because I thought there were more opportunities to make money there. I was right. In other words, I am not an idiot.