I have used Neem Oil (100% – it seems to make a difference) in the past. In fact, last summer I used it with huge success on Japanese beetles! I have a vine, Porcelain vine (alas, someone said it is invasive) that the Japanese beetles love. Love more than Cannas. More than roses! They FLOCK to it! So I doused the vine in neem oil every few days. It didn’t hurt the vine and the beetles fell dead at the bottom of it. A thick, awful blanket of beetles. And my cannas nearby were untouched. So I love Neem oil. I will try it on the lilies, even though I haven’t seen any more disgusting larvae again.
However, speaking of lilies, some of my lilies look really sad. I’ve never had a problem with them before, in fact they spread like weeds. I was feeling very lucky. This year some of the flowers seem misshapen and some have just died (old reliable Casablanca lilies that for the past 5 years grow to 4 feet tall! Now… gone). What gives? My only observation is that we had a late frost this year and they got nipped. Could that be doing it?