Look at it this way, Ismart. If the experiment fails, you will just have nine mantises that die of unfulfilled old age.If it works, you will have one fertilized female and a male who died smiling (or at least, he would be smiling if he still had a head).
Just use a pair of fine dissecting scissors, or those tiny fingernail scissors, and make the snip with the scissor's lower blade directly above the female so that she is not injured when you do the deed. I'll bet you $10 that it will work. And don't forget, it's not length of life that counts, its quality of life!
"(and not just because he cant see her anymore)"
ROFL, Superfreak! Here's to saccadic disinhibition!