I'm not really sure as this is actually a debate :huh: ...I mean, they eat live food, and I'm not sure how feeding dead food would somehow help nutritionally
Oh dear, Asa! Now you've gone and irritated Superfreak!
This will help you.
All animals, both carnivores (lion, mantis) and scavengers (vulture, dermestid beetle) that eat meat, digest dead animal protein. The difference between the lion and the vulture is that the lion captures say, a gazelle, while it is alive, kills it, and eats the dead meat, while the vulture eats a gazelle when it has already been dead for a while. Even snakes and birds, who swallow live prey, do not begin to digest it until it is dead from suffocation. Many carnivores, like canids (wild dogs, foxes) partially digest their prey before regurgitating it for their young. Obviously, the vomit contains sufficient nutrition for the infants' needs.
In captivity, most predatory mammals are fed dead meat and are probably better nourished than their wild counterparts. Many smaller pets, like snakes, tarantulas and, of course, mantids, are fed live prey as much for the benefit of their keepers as for themselves, but the chunk of tissue that a mantis swallows is dead by any definition, and the prey itself is dead long before the mantis finishes consuming it. Many mantis keepers kill and mutilate prey to feed them to "handicapped" mantids, like 'Lectric's two nymphs; other highly successful breeders, like Yen, will mutilate a cricket's head and dip it into honey and pollen to feed to selected species.
The mechanism by which mantids recognize something likely to be living prey in the wild and capture it, is described in mind-numbing detail in Prete (Ch. 10), but the stimuli are readily simulated by an experienced mantid keeper and have been discussed several times on this forum.
For someone who experiences cold winters and whose family does not tolerate escaped live crix and flies roaming around the house all winter, the feeding of frozen insects seems like an ideal, nutritionally sound solution. Fortunately such conditions do not obtain here in Yuma, which is good, because I think that I lack the requisite patience.
Oh yes, while I'm in a preachy mood, let me briefly adress the fear of "bacteria" that has been voiced by several people on this thread. Fruit fly larvae live on bacteria, and the adults are covered in it. Crix eat decaying food and and flies and roaches terrify housewives (domestic engineers?) with the threat of "germs" being introduced into the food with which they come in contact. What makes you think that a mantis's digestive system, which routinely handles all of these bacteria from living insects, can't handle those that grow on them when they are dead?