I second this. Apparently, they are more common on the island? I don't know, I feel like it still took me a while to even find one.
Also, make sure you're trying to catch one at the right time. They are not an "all day" bug like other ones are (8AM-4PM all year is apparently this bug's best encounter time frame on the island). However, tours can run on their own time frame so even if you miss that time frame (and later than 5PM is when they stop showing all together) you can still catch them on tours anytime as long as it still shows daytime on the tour (and ofcourse you have access to the net).
I'm getting most of my information from thonky.com which seems to be a pretty reliable site btw.
P.S. Another thing I remember reading somewhere is, if you move fast enough to a flower without moving too fast, you can get the bug to lift its wings without it flying off, which could help in spotting one. Alternatively, placing bright-colored flowers, like red, next to white flowers could help with spotting one.