Unwanted Bug

A swan plant seed bug on a swan plant leaf. Such a cruel irony. It is here because I have swan plants for the Monarch caterpillars to eat, but I found the last one dead on the ground this morning. Last night it had attached itself to the underside of a leaf and I thought it was about to change to a chrysalis. I went out full of expectation first thing, but now I just want to destroy all the swan plants so that no more beautiful butterflies will lay their eggs in my garden.