There is a beneficial that looks like the stink bug and is in the same family. I don't even remember its name. Unless you know the difference and find that yours are causing damage, don't do anything.

Presuming you've already positively ID-ed them, Stink bugs are hard to kill w/ sprays - I've knocked them off into a bucket of very soapy water - make sure it's deep enough that they cannot easily crawl out.

Watch for the little nymphs - they cluster together & have a knack for staying out of sight.They do not start 'stinking' until they're bigger, so you can safely squish them w/ your fingers.

My personal experience has been that once I find them on my tomatoes, it's a losing battle = (

in case you're still not positive on your ID, here's a link - scroll down to nos. 73-79.....

Here is a link that might be useful: Insects

I use a hand vac to vac them up, then dump them in soapy water to kill. If you get them wet first, they (like squash bugs) will tend to climb up to higher areas (for instance along the top of a tomato cage) to dry out, then they are easier to nab.
Mrs H