I had two of these cool-looking critters on one of my jack-in-the-pulpit plants. Good thing I didn't try to touch them - they can exude a fluid that causes blisters. But I didn't know that then - I took photos so I could ID them. It took me a while since their wings are not at all obvious so I thought they didn't have wings - I wondered if they were the larvae of something. In the end, it was a "go through the insect guide page by page until you find a matching picture" process, but that did work and here are some pictures of Meloe angusticollis.