Yesterday, one of my library co-workers came to me and in appropriately hushed, but slightly panicked tones, told me about some beetle-esque critters that appeared to be munching on her tiger lilies, which are just emerging from their winter slumber. “They look like ladybugs,” she said, “until you get up close. They don’t have any spots on them.” Uh oh, I thought.
(Click here for photo).
This is the dreaded red (scarlet) lily beetle (Lilioceris lilii – isn’t that the best scientific name ever??? Well, next to Bison bison, that is). A little longer and a little boxier than the cute, rounded lady beetle, red lily beetles are not spotted like the beneficial bugs. We never used to have them in Alberta, but apparently they hitched a ride on some lily bulbs brought in from other regions and now we’re beset by the things. Grrrrrr. Unfortunately, according to Sara Williams and Hugh Skinner’s excellent resource, Gardening, Naturally: A Chemical-Free Handbook for the Prairies (essential reading for Prairie gardeners), these nasty eating machines have no natural predators in North America, so they’re pretty much free to run rampant over our gardens, taking out our lilies and Fritillaria at will, as well as threatening wild lily species. (They will also attack Solomon’s seal and lily of the valley, but don’t fret about your daylilies…Hemerocallis are safe from the marauding red horde. Not from jackrabbits, mind you, but that’s a story for another day…). Apparently certain parasitic wasps are used as controls in Europe and we are starting to see some of them here in Canada, which offers hope.
So, what can we do to prevent an infestation? First off, if you get any lily bulbs, inspect both the bulbs and the soil they are potted up in for signs of red lily beetle – either the bright red adults, larvae or eggs. The larvae is yellow-orange in colour and is usually covered in goopy black frass (bug poop. Hope you’re not eating anything right now), while the orange eggs are small and round. Hand-pick adult beetles and larvae and destroy them by dumping them in a bucket of soapy water. (Make sure you have a lid for the bucket to trap escapees!). Williams and Skinner recommend that you don’t buy lilies that are potted in soil to begin with, but they say that if you take the bulbs out and soak them in bleach (the exact amounts and procedure are in the book), you can probably get rid of the beetles.
Throughout the spring and summer, make sure you stay on top of things! Sadly, it may become a full-time job if you have a lot of lilies! The City of Calgary also suggests using diatomaceous earth as a means of successfully desiccating the critters. Bear in mind that red lily beetles are excellent fliers – after they’re done eating your neighbour’s lilies, they may latch onto yours (even mature plantings that were safe when you put them in years ago). Be vigilant…and good luck!!!!
Have you had any trouble with red lily beetles in your garden? What did you do to combat them?
Post updated: May 2018.