As we know France is a big and varied country. I am pleased that you don’t have this phenomenon, but my experience is not your experience. And hopefully the OP won’t have any experience at all of box moths and she is hundreds of km away from my area.
This is a photo taken from the front door just now, and if you look you will see about a dozen moths flying about in broad daylight. Plus a close up of the sedum outside the door - also in broad daylight. Next week there will be nothing. That is what I call a wave. Nothing Hitchcock’ian about it - just a natural somewhat diasagreeable occurance.
You say that in your area the box moth appear about 5 times a year. Strange then that it isn’t in waves like reported in so many areas of France now. We had two waves last year, and this is the third this year.