Cannas: Ick! What worm is destroying my Canna??, 3 by DebinSC

DebinSC wrote:
This little dwarf Canna bloomed beautifully this summer. It has just begun to rebloom but you can see in the photos what I found this morning. This worm had damaged it enough that entire inflo had dropped.
If it were up to me, this creature would be called the "Ick" worm because that's what I said when I found it, "ick!!".

I'd like to I.D. it so I can determine the best way to prevent this happening again.

Anyone know?
Many thanks :)
Deb