Credit to scharn73 @ ps3trophies.org [ http://www.ps3trophies.org/forum/earth-defense-force-insect-...
This method will get you 2-3 waves per 10 minutes with you away from the controller most of the time. as scharn73 says, it is "slow" but you spend less time actually playing.
1. Rubber band the right stick to point left or right
2. Rubber band the right trigger.
3. Start Map 1: Cornerstone in singleplayer.
4. Jump in the turret. (Drunk walk over there, since your stick is rubberbanded.)
5. Come back in ~10mins to restart.
1. The turrent usually lasts until wave 4 for me, when it usually blows up and I eventually die.
2. Sometimes the turret blows up in wave 3, and its helpful to have the 4 round shotgun equipped to finish off the stragglers. (But sometimes you just die.)
3. At odd times, some spiders will get stuck behind buildings, requiring you to get out to kill them, or just restart.