A stink bug on a stinking iris seed

Our garden has hundreds of these Iris foetidissima (also known as stinking iris) throughout it. We have removed a huge number but will leave the rest until next year because there is so much more we want to be getting on with in the garden. They get their name from the leaves which have a foul smell when crushed although I don't find the smell too unpleasant. They produce seed pods that split open to release lots of shiny orange/red round seeds which is why we have so many plants in the garden. It must have been fashionable to plant them when the garden was established.  Today I cut all the seed heads off - a bucket full - so there are no seeds to spread. 
This shield beetle (stink bug) obviously finds the seeds pods attractive.