The Battle Against Red Lily Beetles and Where They Were Hiding
Lilies are a cherished addition to our Zone 3 gardens here in Northern Alberta. With their vibrant colors and graceful blooms, they establish well, thrive through our short growing season, and best of all—they’re tough. Unlike many other bulbs, lily bulbs don’t need to be dug up each fall. They endure the harsh winter and even multiply, rewarding gardeners with more beauty each passing year.
But with beauty comes the beast—the red lily beetle (Lilioceris lilii).
First Signs of Invasion
Last year, I noticed these striking but destructive beetles on my lilies, along with their unsightly larvae. That’s when the war began. These beetles may look pretty in their brilliant scarlet armor, but they’re anything but welcome. As soon as you approach the plant, they drop to the ground and lie on their backs, becoming nearly invisible against the soil. Sneaky and frustrating.
The red lily beetle lays tiny red eggs in neat rows on the underside of lily leaves. Before long, they hatch into larvae that look like little black blobs of goo. This goo is actually their own excrement, which they use to disguise themselves—another unpleasant feature of this garden pest.
Methods of Control
The recommended method of control is to remove beetles and larvae by hand. Gloves are highly advised—especially when dealing with the larvae. You can also dunk them in soapy water to kill them, but that’s not always practical when you're mid-patrol. I often just squash them on the spot. Soapy water works on larvae, but unfortunately, adult beetles are immune to it.
This spring, my battle began early. Even before the lilies had emerged, I found red lily beetles feeding on my Sweet Williams, which were the first plants to leaf out in the garden. It turns out they’ll feast on other plants while waiting for their favorite host—lilies.
Preventing the Spread
I was also told about an interesting method: dunking lilies in a mild bleach solution before giving them away. While it doesn’t make sense to dig up and bleach all your own plants, this can help prevent the spread of beetles to other gardens. The mixture recommended is ½ teaspoon of bleach to 2 liters of water. This could be a responsible step if you're sharing or trading lilies with fellow gardeners.
A Broader View
To dig deeper, I reached out to Olds College, and they provided excellent research-based information on lily beetles:
🔗 Olds College Lily Beetle Research
Their research confirmed much of what I’d observed: while chemical solutions are limited, vigilant manual removal remains the most effective strategy.
What's Happening Elsewhere?
Interestingly, my daughter in St. Albert reported no lily beetles this year, though she struggled with infestations in the past. Whether her municipality is spraying or if it's just an off year for beetles in that area remains a mystery—but it’s worth looking into.
Call to Action
If you're a fellow gardener dealing with lily beetles—what's worked for you? Have you tried neem oil, beneficial nematodes, or any other methods with success?
Let’s keep this conversation going. Red lily beetles are a formidable foe, but with community knowledge and shared experience, we can better defend our gardens.
