[Leaf Miner damage and control][1]Looks like a leaf-miner of some sort...the light colored wiggly lines is what was eaten and the black is fracas...poop. Gotta see the insect itself, really to suggest how to treat.  Is this plant outdoors or indoors?  Please send pictures of the undersides of the leaves.  Some leaf miners actually live IN the leaf. If you could turn the leaf over, look for slight bumps. Use a razor blade and carefully cut the bump to shave leaf and see if you can find insect.  It'll probably look like a tiny worm...investigate while leaves are warmed from the sun and also while night.  If you can't see anymore damage happening it might be because the insect has matured and flown away leaving eggs inside the leaf.  Just use leaves that are new and undamaged for now.


  [1]: http://www.gardeningknowhow.com/plant-problems/pests/insects/leaf-miner-control.htm