Not Just a Pretty Bug!

It was during a visit to the suburbs of Montreal, that I first saw the lily leaf beetle, Lilioceris lilii, to give it its real name. This magnificent metallic orange insect was happily flitting about on what had undoubtedly been a lily earlier in the season. Now it had no leaves and looked more like an asparagus shoot. I didn’t hesitate for a second and, thanks to my lightning reflexes, before I even had time to repeat its name, I took a photo. July 15, 1998: how could I ever forget that fateful moment?

Once the photo was taken, instinct number two—kill, crush, destroy—kicked in. So I tried to grab it between my thumb and index finger to crush it.

Historic Moment

In fact, although I had never seen one before, I had already heard about this insect, whose description and the damage it causes have been filling desperate emails from the southwestern part of the province for several years. However, my attempt was in vain. The leaf beetle, seeing me coming, dropped to the ground and it was impossible to find it. I now know that the leaf beetle, not so foolish after all, throws itself to the ground and turns onto its back when it feels threatened. In doing so, it hides its bright orange shell to reveal… a black underside that easily blends in with the soil.

I was delighted with this historic photo, especially since, like all Quebec City residents, I was convinced that this was strictly a Montreal problem. There was no way that this insect, which originated in Europe (and was first discovered in North America in Montreal in 1945), could survive Quebec winters!

Panic in Quebec City

So it was a blow in June 1999 when one of my lilies showed strange symptoms: holes in the leaves and flower buds. I went closer to take a better look at the damage, and what did I see? A leaf beetle as bright orange as its Montreal cousin.

This time, I was quicker off the mark. As soon as I saw it, I squashed it: it makes a crunching sound when you crush its shell between your thumb and index finger. Half an hour later, I had squashed 15 adult beetles, a dozen slimy larvae (they look like mini slugs and are covered in their own excrement, no doubt to discourage predatory birds… and disdainful gardeners), plus a surprising number of orange eggs, hidden, like the larvae, under the leaves. I quickly called friends in the area who also grow lilies, but no one had seen anything… yet. Two weeks later, my email was overflowing, as was my answering machine: what is this pretty insect (everyone agrees it’s beautiful) that is causing so much damage to our lilies and fritillaries? It was panic in Quebec City!

How Can They Be Controlled?

Three years later, I still don’t know how to control them properly. Okay, I squash them, squash them, and squash them, easily destroying the first generation, but around July, the second generation, more mobile and numerous than the first, arrives and the damage starts all over again. Manual control becomes almost impossible, as I refuse to use toxic products in my yard. I have spent 45 years (assuming I started gardening at the age of one, which seems highly likely, knowing my gardener father) refusing to use dangerous pesticides, even when insects threatened my vegetable garden. I’m not going to give in to temptation just because a new insect is attacking a common ornamental plant!

The Solution?

So I didn’t follow the advice of my neighbors who use malathion (never in my yard!) or rotenone (okay, it’s “organic,” but it’s still a toxic product!). To date, diatomaceous earth (finally, something that controls insects without poisoning them) is only effective when it’s not raining… but it rains all summer in Quebec City. Some recommend neem, because this organic oil, derived from an Indian tree and completely safe for all animals except insects, is not only an insecticide but also a repellent. Unfortunately, it is not approved as a pesticide in Canada and therefore difficult to find. Are there any other solutions?

I see one on the horizon. I really—and I mean really—want to rip out all my lilies and be done with this problem forever. After all, the world is full of beautiful plants that don’t cause any trouble. Why keep a plant that does?

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Larry Hodgson published thousands of articles and 65 books during his career, in French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This article on the lily leaf beetle was originally published in Fleurs, plantes, jardins in July 2001.