Finally, they’re here. For at least 5 years, now, I have been hearing tales of destruction and dire prophecies from friends and garden visitors who live to the east and northeast of Buffalo. “Do you have the lily beetle yet? They’re everywhere in (Rochester/New England/Ithaca, etc.). I don’t grow lilies any more. They ate them all.”
Cringes of horror all around. I assured the visitors I had not seen this dire creature, but they assured me it would make its way west. And it has; indeed, I’ve read about infestations in Wisconsin and Seattle, so maybe it bypassed Buffalo at first as it swept across the country. Or maybe it took a while to find its way into the urban core.
I have not experienced any widespread devastation (yet), but everything I’ve read and heard is true. The red beetles nibble away at leaves and lay eggs, which grow into repellent black masses of goo that feed on the leaves’ undersides. They are gooey because they carry their excrement on their backs, apparently for protection. You can just wipe them all off, though. You can also pick off the red adults (quickly) and squish them or throw them into soapy water. This must be done every day. Had I thought about it in spring, I could have sprinkled some kind of anti-grub substance like diatomaceous earth as the lilies poke their heads up. (Haven’t seen anything definitive in the Garden Professors’ various sites.) In New England and parts of Canada, Tetrastichus setifer wasps have been released. They attack the larvae and lay eggs so that the next spring, more wasps are hatched, rather than beetles. Pretty neat, huh?
For now, I am pinching the adults off and wiping the leaves. The larvae drop into the soil and emerge as adults within a month, according to my reading. I have noticed my lilies in containers have little or no signs of beetle. Kind of makes sense; nothing can overwinter because I usually plant them in the spring or in fall with fresh soil and no leaf debris. So that’s one thing.
The other thing is that I do not have big stands of lilies. They are sprinkled throughout the perennial beds, most of their stalks purposely hidden by shrubs and other perennials. Casualties will not be missed, at least in terms of aesthetics.
So there you have it; if I can post lots of lily pics in a few weeks, we’ll know I’ve been at least partially successful—and next spring I will be taking preventative action, if that’s what works.