[Kirpi]

I have Mullein Moth caterpillars on my plot, which is fine because I have a few Great Mullein plants in my flowering bed and they are specific to this plant, buddliea and mugwort and not any of the veggies I have.

It's always worth making sure you identify a caterpillar before you pick them off and destroy as they may be beneficial for pollination when they hatch as butterflies or moths.  The Mullein looks very much like the large cabbage white caterpillar but much brighter and has alternating silver and green segments.

Does anyone know what the Mullein moth uses for nectar?

[Yorkie]

http://en.wikipedia.org/wiki/Mullein_Moth  suggests Buddleia as one plant?

[Kirpi]

Yes that seems to be a staple nectar food for most butterflies and moths as well.

I have seen folks with well pruned buddliea on thier plots, but as it is also a magnet for cabbage white butterflies, I have always found it difficult to justify having a Butterfly Bush on my plot.