I completed all badges within an hour or two.
I brought a FULL firefly jar to a BIG swarm, and I was able to just open the jar (releasing the fireflies that were in there) and collect at the same time.
There were enough of them to just sit there and open and close the same jar the whole time. So much easier.
I'm sure lots of you know this, but I thought I'd post it for those who didn't
-- ♥ Jess