Lately, I've been hearing a great deal about 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 with the things. Grrrrrr. Apparently, 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. (Don't fret about your daylilies...Hemerocallis are safe from the marauding red horde. Not from hares, mind you, but that's a story for another day...). I've read that certain parasitic wasps are used as controls in Europe and we may eventually see more of them here in North America, 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 anything you see that might be a red lily beetle and destroy it. If you can help it, don't buy lilies that are potted in soil to begin with, but if you take the bulbs out and soak them in bleach, you can probably get rid of the beetles.
Throughout the spring and summer, make sure you stay on top of things! Watch your lilies for signs of the adults or larvae and hand pick and kill any culprits. I've also come across suggestions to use 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?