I couldn't figure out how to plant citrus, so I have no bug repellent. If you've ever been to the South Cave, you've seen hoards of these evil things.

I suggest to use a Grappling Hook to hang from the cave ceiling and fill these monsters will Bullets or Arrows. You can get Grappling Hooks from the Reloading Bench, a crafting station available at around Level 30 and costing only 50 Amber.