Holes in Maple Leaves

[drawing_blanks]

Hi all,
I was very surprised to see the leaves on my young maple tree riddled with holes, eapecially the lower leaves.
Does anybody know what pest I'm dealing woth here and how to fix the issue?? Any help on the matter is appreciated.

 

[arathol]

Caterpillars maybe? Any sign of gypsy moths in your area?

 

[BC WetCoast]

Looks like what we call spanworm, which is a caterpillar(inchworm). There are a couple of specific species it could be.
We spray for it with BtK, a pesticide based on a bacteria, which when eaten by the caterpillar blows up in its stomach. BtK is very specific to caterpillars and doesnt harm other insects like bees.
We also use pyrethrins, but they are a little less species specific.