Start to check for red lily leaf beetle in WNY

red lily leaf beetles mating
The sooner you can reduce the numbers of the red lily leaf beetle, the better off you will be. Handpick the adults off the leaves before they can reproduce. Photo courtesy Gordon Ballard

by Connie Oswald Stofko

I received this message from Tess in Binghamton: “Red lily beetles have arrived early! Picked a dozen of them out of the flower bed today, March 20, 2020, in Binghamton NY area!!”

It’s not too early to start looking for them in Western New York, said John Farfaglia, extension educator with Cornell Cooperative Extension in Niagara County

“They do show up early, as soon as the foliage breaks ground,” Farfaglia said. In past years, “I’ve gotten calls about them as early as April. If they’re not on your plants yet, it won’t be long.”

The red lily leaf beetle damages true lilies as well as fritillaria, an early spring flower. It doesn’t damage daylilies.

See more background information on the invasive red lily leaf beetle here.

Best way to deal with red lily leaf beetle

“Handpicking the adults is the way to go,” Farfaglia said. “The sooner you can reduce the numbers of adults, the better off you are.”

When the foliage is small, it’s easier to see the adults, he said. It’s better to go out every day rather than just once or twice a week.

“It’s worth doing if you like growing lilies,” he said.

To pick the adults off the leaves, you can wear gardening gloves if you like. Knock the adults off of the leaf into a cup of soapy water. Or you can crush the beetles with your fingers.

Don’t try to use any spray on the adults; sprays are targeted to the larvae, he said. It takes about a week for eggs to hatch, so if you don’t get the adults, you will see larvae soon after.

If you must use a pesticide, neem oil will work on the larvae. However, if you need to treat your plant, do it before the flowers open. Don’t use insecticide on a plant with open flowers.

11 Comments on “Start to check for red lily leaf beetle in WNY

  1. Connie, my plan this year (first full year without lilies–and have you had those beetles? They spread their poop on their larvae so your garden stinks to high heaven) is to put in day lilies as I have tons of those and LOTS of space where the other lilies used to be. I’m not sure how that will work though. The lilies bloomed at just the right time and height and colors…so sad.

  2. Just a reminder to your readers, that this newest pest we have to contend with only affects plants within the “lilium” family, generally bulb plants. They do not affect “hemerocallis” (daylilies) which grow from a root structure and crown. If you find yourself in a predicament with containment of this outbreak, often you can find an appealing replacement from among the over 90,000 registered daylilies available from which to choose. Our recommendation however to to visit and select from those available through local specialty daylily growers, to insure your selection is hardy for our region.

  3. Terry, what would you like your replacement plants to do? Be tall? Fragrant? Flower at a certain time during summer? Easier to grow? Lilies need sun, and there are lots of wonderful plants that do well in sun. You have lots to choose from!

  4. The latest issue of Fine Gardening (June 2020) has a brief article about the bug. “The adult beetles are …bright read, while their slug-like larva are orange-green, They over-winter in the soil or leaf litter of lilies as adults, emerging in spring to early summer to lay eggs, which are tan. These eggs are often found on the undersides of leaves in irregular lines.” The article goes on with the same cautions about insecticides and treatment with Neem oil or insecticidal soap. Hand picking seems like the most effective control if there aren’t too many bugs. Hope this helps with identifying the larva and eggs .

  5. Another great, informative article. Very useful content and to the point. Thank you, Connie!

  6. I tried to pick these suckers off the first year. By the second year, there were just too many to even attempt it and I pulled all my lilies, which were a huge part of my perennial garden. Would love suggestions on what to replace them with.

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