Chris
@Semmering.
Sorry about the late reply. Lily beetles do seem to have a real appetite for Martagons. I guess all that lush early growth is hard to resist. LO hybrids and Lankon are also early favorites for them. Crown Imperials used to be my capture crop, but haven't worked as good since I planted Martagons... Could be a coincidence more than something else.
Unfortunately I think your strategy will have some obstacles to overcome, so might be less effective than you think. For starters, delaying the emergence of your Martagons would also delaying some of your lily beetles as you would mulch those as well. Also all lily beetles don't emerge at the same time. While lily beetles larvae need lilies to be able to grow to full size, the adults are also said to be able to feed on other plants. You also may have the problem with lily beetles flying in from neighbors if they grow lilies. This can be a significant problem right from the start of the season.
There is also the closely related species Lilioceris merdigera which looks very similar to the lily beetle and feeds on lilies too, but it has a more diverse appetite and that includes the larvae.
As for late to emerge lilies this certainly seems to differ between climates. However down here in Skåne, I noticed that many of the American bred hybrids are a bit later than the Dutch bred. No lily is later to emerge than 'Red Velvet' in my garden. It doesn't seem to be a favorite in spring for lily beetles, but they will feed on it later in the year.
