GA: Leek moth in uncovered onions?

A few days ago all of a sudden the uncovered onions started looking they have leek moth damage.  I'm not totally sure though because when I removed a few of the worst leaves and slit them open, I didn't see any larvae.  

Also, the covered sets' cover broke a week or so ago so I had removed it altogether, but today I decided to cover it again with a new cover.  But likely there are some leek moth eggs/larvae in there.

Planning to spray some BTK, but lately it's been raining every day, so not much point in spraying right now.