Well I've come to the conclusion that I have carrot flies!
While taking my daily walk through the garden after work I walked over to a container I had planted some carrots seeds in last year that never came up. The seeds had overwintered and started to sprout about four or five weeks ago. When I was looking at the carrots I saw two flies hanging out around one of the carrots that was just above ground.
I hadn't planned on leaving the carrots there to grow. I'm going to pull everything out of the container (including the soil) and put in a few strawberries.
I'm hoping luck was on my side and the carrot flies were unaware that I had planted four squares in bed 1 with the tomatoes and one square (so far) in bed 4, which is only five feet from the container. I'm not worried about bed 1 since it is completely enclosed in clear plastic to keep the tomatoes warm. I didn't cover the one square in bed 4. But after seeing the flies fly off the carrots I thought I'd better do something to cover my seeds to deter them.
Here is what I came up with...
Cute and functional...
I may pick up a few more at the dollar store to keep on hand.