Leaf miners on gazania

Can I leave them or should I pick off the leaves?
There's an awful lot of them so I wouldn't be left with much foliage.
I'm not too bothered about the appearance as the flowers will hide the leaves.
What I'm really asking is, will they do catastrophic damage to the plants?

 

I usually just pinch the leaf,with insect, between my fingers rather than removing the leaves.
You probably need to get the sun behind the leaf to actually see the insect.
If not it will be at the bigger end of any particular trail.

 

Thanks @pete ,
That'll certainly be less destructive.