Prevention is the first step to ensuring these pests are not present in a crop from the start.
Ensure that all debris and over-wintering sites are removed in or near the growing area, leaves, and weeds being the biggest culprits.
It may also be helpful to rotate between growing sites outdoors to make sure that they are properly ploughed and cleaned of all debris as well as possibly treated with beneficial nematodes or insects.
Excluding the hemp borer moths from the site can prevent eggs from being laid, so using protective netting or promoting predatory birds or a night light trap is important. The eggs can also be targeted by using preventative treatments of parasitic wasps such as Trichogramma minutum or assassin bugs, this will reduce the amount of damage an infestation could cause if eggs are laid.
Another tactic may be the application of horticultural oil or pesticidal oil to coat and smother the eggs if other methods have proven to be unhelpful.