I have never used a tripod for macro work in the field. It is EXTREMELY cumbersome, as has been said. Think about it..go outside and get about 12" close to a fly and wave your arms about slowly between the two of you. See how long it stays there. It wouldnt stay long at all. That being said, it's quite fun to take macro videos, I've posted 3-4 on here I have made, and that is where a tripod comes in real handy. Especially one with a removable center column, like has been said. The ones that have the column that extend out the side are just pointless for Macro because the extra extension gives way to some pretty intense wobble. You have a camera, and an amazing macro lens. Just go run about and play with it. Get a good tripod, a Manfrotto would be ideal for most cases, and don't be shocked by the price tag. It will litterally last you the remainder of your life if you treat it well. Hell, even if you don't treat it all that well probably. It's well worth the investment. These two purchases don't necessarily couple together.
Mark