Attached is picture of 3 week old seedlings. All show signs of damage by something, but what? It is not a large insect, as seedlings are covered with 3/16" wire mesh cage. Sierra foothill, California area.
Lupine Seedling Problem
Certified GKH Gardening Expert
Not a large insect - but, perhaps, small ones. They kinda look like they have been damaged by thrips. Here is a photo of thrip damage similar to yours: https://bit.ly/1OYKnVz
Here is an article on how to deal with thrips: