When I was growing commercially Enviromesh or maybe it was Wondermesh was the order of the day for pest exclusion – brassicas, carrots and we even briefly thew it on top of the onions to the stop the birds pulling them out when just planted….so I am well familiar with it. I decided to use butterfly netting this time as it seemed less of a barrier and afterall it’s only the catapillars to worry about (!)…..may need to reinvest next year….
I do wonder though – reading a bit about them online – they bury into the soil and over winter there – what’s to say they don’t turn up underneath the mesh when already in place?!!!