How should I set up my island to best farm beetles? Should I move all my mango trees to the center of the island in a line?
I don't think there is a "best" set up. But here is a pretty optimized one:
- Destroy all flowers. This will prevent butterflis from spawning.
- Chop down all non-Palm trees. The beetles on the palm trees are all worth 6,000+. If you are think you might want to grow the normal trees again, leave one standing to harvest its fruit for repopulation.
- Plant more palm trees if you wish.
Now the set up is done. When you go beetle hunting, chase away anything other than palm tree beetles (wharf roaches, hermit crabs) and only catch the palm tree beetles. If you still have a normal tree, I would recommend chasing away Miyama, Fruit, and Dynastid Beetles, they aren't worth much. The giant stag grows on these trees, and is worth a decent amount, so catch that if you see it.
I usually just walk in a circle around the beach, walk slowly and creep when you see a beetle. Some of the rarer beetles have low tolerance for noise. It's also useful to note that you don't need to be any closer than the edge of the tree's shadow in order to catch the beetle. If you get closer than that, you will most likely scare them away.
I usually haul in 300k per trip to the island this way.