How do you get the bug at the top of the throne room in Zelda twilight princess?

The one you are most likely trying to get is at the top of the room on a wide ledge. To get there look for a platform on the east side of the room with some ivy on it. Get near it and your little buddy will help you jump up. From there just keep jumping up platforms. Once you get to the top of the waterfall, go behind it and jump across using her help again. When you see some green coins just sitting there, follow them down to the ledge. From there you will be able to get the bug.