Well use arrows to stun him (works best when he's "dancing") and then go in to hit him with your sword. You can also try to hit him with bombs or just try to hit him with the sword directly. Usually I just keep my distance and try to hit him with arrows. When he sends bugs after you, just throw a bomb and they follow it instead of you.
You can hide in the floer at the center and pop out when he is over you,
Attacking him with your sword at any given chance works well,
Keep a fairy in a bottle,
bombs and arrows are effective,
be creative and you'll figure him out.
just do what i do. and if you do it right, youll have him beat in no time!
from what i noticed, the battle i think is about 3 parts
1st part: hide in the flower, of use any special deku abilities you can think of. and use the shield!
2nt part: shoot him with arrows and hit him with your sword as much as you can
3rd part: become good at using the no charge spin attack, and he should be easy
Use your shield whenever he swings and after he hits use the Z Target + A combo. Its all about timing, but if you got that then he is the easiest boss in the game.