Lupine seedling problem

Question

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.

• 

Answer 1

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:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm