do you have the mushrooms badge? what was your tactic?
Yep, I think I ran a route like this:
Long range rings like Solar Rays are your friend, as are Fleet Feet and Coyote. I actually kept my CL around 2.0 when I was killing them so I had Mantis, but I also wanted the loot. Other then that, it helps if you have a whole lot of patience. xD