Hi, I was wondering what were the trees you kept/chopped off this island when trying to get these bugs? Some people keep all the palm trees while others get rid of specific ones. Sorry if this is stupid, just curious.
Not a stupid question. This may not be the best tree layout, but I usually have three to four palm trees on both the left and right of the island, plus one or two fruit trees in the center.
The big bells beetles (Golden Stag, Horned Hercules, Cyclommatus Stag, and etc.) don't spawn on the center fruit trees--only palm tree trunks.
The Rainbow Stag and the Giant Stag will only appear on the center fruit tree trunks. If you're not interested in catching them, you may want to chop down the fruit trees in the center.
Three spaced fruit trees in the centre part of the island
One stump (for some bugs that land there)
Two palm trees (one of the far left and the other on the far right of the island)
Having the palm trees spaced farther apart and walking at normal pace encourages faster spawning.
I wouldn't recommend placing palm trees on the south of your island, these are harder for sneaking up to bugs.
Remove flowers and bushes to stop less rare bugs (butterflies mainly) as these take up the spawn count.
Scare away the fruit beetles, saw stags, miyama stags, horned dynastids on the centre island area and scare moving hermit crabs on the the beach to encourage rarer bugs to spawn.