lotus, it would have been better to have started a new thread rather than pulling up one this old, but there is much confusion about these, as well as many other, bugs. Before anyone can tell you what to use to control any insect in your yard and garden we need that insect properly identified and it needs to be a pest. Some of the insects in the Assassin Bug family are beneficial while others are pests, but pest control also starts at the root of an organic garden and that is with the soil. Look into your soil to be sure it is good and healthy so it will grow strong and healthy plants that are better able to ward off attacks by insect pests. Here is a link that might be useful: Assassin Bugs

Looks like some kind of assassin bug or leaf-footed bug, either of which will eat your Monarch cats. Take it far, far away from your Milkweed. Fascinating bug and good find

They appear to be Leaf Footed nymphs, and below is a link showing pictures and identification: We used to see Wheelbugs(assassin bugs) in our garden and around the house(never indoors though). They had an early nymph stage that appeared orange, but only the far rear abdomen as orange, with the forward half on the thorax and head black. http://thecitrusguy.blogspot.com/2012/06/you-put-your-leaf-foot-in.html

You can differentiate between the Stinkbug nymphs and the Assassin Bug nymphs by the tail end. I have a little blurb that helps me: "Bad Black Bump" which is what the Stinkbug nymphs sport on their butt tips when they are smallish and congregating like little orange ants with long black legs. The clue is "congregate". Stinkbugs are groupies, and usually appear as a whole mass of them together, usually on top of your best tomato... Assassin Bugs, true to their name, are singular and solitary. You will usually encounter them one at a time, or, in my case, if you have a "herd" of them in your milkweed, you will see them down there with adequate space between themselves, and being rather territorial... I consider my "herd" of Assassins to be Allies. They patrol the grass and milkweed and keep EVERYTHING from crawling up to my veggie plants. The downside is that they are afraid of nothing, and will kill EVERYTHING in their path, so this means they do take out some of your beneficial bugs (bennies) as well. However, it's a trade-off, 'cause the bennies might relocate to the other side of your yard and be very safe and happy... Linda