I have wrapped the base of my plants with aluminum foil and it seems to work....

the moths lay their eggs at the base of the plant and once hatched they bore in ....

The base of the plant is the primary target, but they also lay eggs on the under side of leaves, and at the leaf stems... etc... covering the whole plant and then uncovering to pollinate the flowers is probably your most surefire method, but if there are any that overwintered in the soil, they could still come up under your covers. Injecting BT has worked for me, but it is a major chore to keep up with.

When the wild chicory blooms, the moths fly at dusk. No need worrying until then.

Here you go. More than anyone probably wants to know about SVB and the various controls.

Dave

Here is a link that might be useful: SVB Control discussions