Yes, sorry folks, but yesterday I found my first three Lily Beetles: and two of them were copulating!! I put a stop to that, I can tell you.
Last year, it was mid-may before I felt moved to remind you all to be vigilant against Lily Beetles, but this year they are clearly starting early, so now is the time to get out and check your Lilies and your Fritillaries.
If you don't know what they are, or if you've forgotten what they look like, then I'd suggest you take a quick look at my Post on the subject from last year. In a nutshell, they are bright shiny red things, unspotted (therefore easily distinguished from Ladybirds), and the adults eat the leaves, to give them strength to produce bright orange eggs which they lay on the undersides of the leaves. When these hatch (after a disgusting development period which entails covering themselves with their own faeces for disguise), they eat what's left of the leaves, and your Lilies are ruined.
The best solution is to check them several times a day, and squish any adults that you find, before they get a chance to lay eggs. Be warned - they have hard carapaces, so when I say “squish”, I mean “crush underfoot, or guillotine with a thumbnail if you are not squeamish.” After more than a decade of doing it, I am no longer squeamish.
As mentioned last year, they have one more nasty little trick: when you try to get hold of them, they fling themselves off the leaves and lie on their backs on the ground. As their undersides are black, they are almost impossible to spot against the soil, so either cup one hand underneath the leaf to catch them, or crease a sheet of paper lengthwise, and hold it under the plant. Either way, once you have them, crush them!
As with so many aspects of gardening, prevention is better than cure: there is still just about time to spray your lilies, if you don't fancy the search-and-destroy routine. Most of the sprays are systemic, which means that you spray them onto the leaves, the spray is absorbed by the plant and circulates to all areas, the lily beetle eats the leaves which now contain the poison within the sap, and the beetle dies. Alas, they might still have time to lay eggs, so spraying is not a cure-all, but it can help to cut down infestations if you can get it on in time. So if you plan to spray, now is the time.
And while you're at it, spray your Solomon's Seal (Polygonatum) as well, in order to get the poison inside the plant before the sawfly larva come along and chomp them to skeletons again!