So are we talking movie, book or game bugs?
So, against all the bugs - nuke them (haha) phaser, photon torp them from space. Don't land against the book bugs.
We really don't know the Bug ship capabilities - however, given the humans managed to get to Klendathu a couple of times, the planet can't be that heavily defended in space.
I'm just going to say...BIOGENIC VIRUS. Ought to kill the bugs pretty good, and do it all the way across the galaxy.
"Our cash flow is as if a profligate son keeps borrowing money to spend on Geisha, which is why we donít have a choice not to enjoy the race." ~DOME CO. LTD, on their 2012 LeMans effort...