In the last couple of years I've taken to using a Vine Weevil drench on all my pots (predominantly Narcissus, Tulipa and Fritillaria). The drench is quite expensive but I felt it was worth it to protect my bulbs. This year I noticed a considerable reduction in Lily Beetle infestation. In fact, I had three - one on a Frit in Spring and two on L. pyrenaica. All beetles looked decidely lethargic or dead. My neighbour's lilies across the road were infested. Any thoughts/experience on/of this approach?
Jack