Caught a few box months when next to spray ?

[coveruplep]

My lure trap has finally after 3 month caught three box months. I had previously done a lot of spraying to get them under control as half my buxus was eaten, but when should I spray next? It's obviously expensive to do it too often.

I have the same problem with my buxus hedge. I have read that the first year you discover them
you should spray every two weeks until it’s under control. Once under control once a month ( the season for them is March to sept/oct) . Then in the new season spray at the very beginning of March and keep an eye for the webbing to appear. I guess prevention is better than the cure. I’m going to give this a go as I don’t really want to replace it. Then hopefully next year I have more of an idea what I’m looking for . Good luck !