Muddy, I think anywhere the emerging nymphs can find a nymph size
carnivorous meal as they fan out from their eggcase will be fine. All .of the plants I mentioned are in an area of my yard that had plenty of aphids until I removed a huge wild multiflora rose last year. Also, I have been plagued with flatid planthoppers whose nymphs are abundant on the shrubs I listed and emerge about same time as mantids in spring.
http://bygl.osu.edu/node/348
Because of far fewer aphids, I think my mantids did agreat job of bringing the flatid population under control. Anyone who has an organic veggie garden or a few tomato plants can use a mantis egg case or two for bug control. The annual egg case or two in my fountain grass gets tucked into the clump after i trim it back in spring as I never can tell for sure that the babies have emerged! It is near my tomato patch.
When they emerge, they really do come out all at once, and keep streaming out! Hundreds of them! Within fifteen min they fan out in all directions about ten feet! They are tiny total miniatures of the big ones...so cute. So glad to have seen that. They also will eat each other so don't worry about two egg cases in your yard...nature achieves a balance fairly quickly.
Some sweet 'bonding with mantis' stories here:
http://www.instructables.com/c...