who's chomping on my cannas?

I just noticed these holes today.
There have been japanese beetles on them but that damage is lacy looking.
This is so even and symmetrical!

At first I thought it had been chomped while the leaf was still unfurled but they've been open awhile and I look all the time since they are blooming finally...and I think the holes would be different then, not as even.

There was a small grasshopper and an ant on the back of a leaf ...maybe a leafcutter ant?

any ideas?

I really like the holes so am not looking to punish the chomper...I just would like to know who did such a methodical pattern.....some are almost rectangles, squared off rather than round holes.

how very strange, it almost looks like something stepped on them, almost like a grid in some parts. was there a windstorm where maybe something could have hit into them and caused the damage?
(to my knowledge leafcutter ants always start from the outside in, I've never seen them start inside a leaf)

Tereza, The leaves are fairly rigid so if bent they would not have revived upright if blown over....had not been thinking of an imprint but I can't think of anything that would have done that near by?

Will have to inspect with a non bug something in mind...I do have a short circle of fence around the base...

It's noticable on two leaves...the one on the right not as neat but still in rows.

I just looked around and there's nothing 'non bug like' that might have made that pattern.
I first checked the short bit of fence at the base of it and it's heavy hogwire...no little pokey things in a pattern.