Seedlings are only about 1 true leaf. I have never seen Spider mite but looking at the pictures on line, i think that is what I have. On the white foam cup surface, with my eye sight, I could only see the red little spider like structure walking fast, not jumping. I squashed it with my finger, it left a line of red pigment.

Some of the leaves are turning mottled white. Since the seedlings are so small, I am afraid they may kill them quickly.

What can I spray that will not kill the seedlings too?

Thanks for the help.