I've experimented with those Halyomorpha halys. Wouldn't it be too good to be true if mantids ate them? It is too good to be true. Even mantids won't touch 'em. Nor birds. That's why there are so many.
Some mantids will eat them, some will take it, taste it, then drop it. It depends on the mantis. I had a mantis hanging around my house for a few days and he ate a stinkbug. he only dropped it when someone walked up to him.
Funny Rebecca! I've tries these brownies with Chinese and Carolinas but both species wanted nothing to do with them. Love to get a few that *will* eat the stinkers. It's a full-time job to gather the little twerps and flush 'em.