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fighting lily leaf beetles organically

lily leaf beetle 2IDON’T USE CHEMICALS, but that doesn’t mean I don’t fight unwanted garden pests. At the moment the primary skirmish is with the lily leaf beetle, Licioceris lilii, who happens to be my favorite color–a sort of Asian lacquer red–but otherwise much-loathed here. And so these days, I am out hunting, on a search-and-destroy mission for the small but voracious pests who also like Fritillaria and Polygonatum (Solomon’s seal) and a number of other garden plants not captured in their common name. Ready for a fight? Onward, organic gardeners, onward…and don’t forget to get the beetle eggs, too. Here’s how:

Much in the same way I deal with everything from tomato hornworms to adult Japanese beetles to Viburnum leaf beetle and tent caterpillars and even the occasional slug in a wet year, my approach to lily beetles is manual–as in pick and squish, or drown.

lily leaf beetle eggsYou have to get the adults, and also the eggs, which start out tan and then go from orange to red when they are close to hatching. They can be found wherever there are copulating adults (which is anywhere that adult beetles are, it seems from their flagrant behavior), on the undersides of leaves in uneven lines like a bit of a tiny zig-zag. Squish!

Since the beetles overwinter in the soil, the minute lily or fritillaria foliage emerges, there are hungry beetles to damage it, too–meaning if they’re in your area, you probably are already seeing holes. Even if you didn’t get started right away, begin hand-picking beetles and eggs now to minimize the exploding population; remember, these are sexy beasts, so keep removing adults and eggs or else.

You see, I’ve left the worst for last: the part about what comes between the egg and the beetle. The larval stage of this pest is extremely ill-mannered, covering itself in its own excrement as if to just dare you to touch it. It is also the most voracious and therefore most damaging stage, so knock off those beetles and eggs now, and avoid the filthy little slug-like slobs altogether. Work fast when you pick, since adults will quickly disappear by flying off the plant and turning upside down in the soil as camouflage.

The use of parasitoid wasps to cripple the beetles has been very successful in European tests, and in a few research studies domestically, but is not available as a consumer product nor widespread enough yet to help in most areas. (The Rhode Island link below gives an update on states that have released various species of the parasitoids.) If you have more than a few clumps of lilies, lily leaf beetle can be controlled in some stages (particularly the youngest larvae) with spray products containing Neem. Me? I’ll just be out picking.

more details on lily leaf beetle

THE LILY LEAF BEETLE, of Asian origin, has founds its way into six Canadian provinces and as many states in the Northeast, most recently making its way into northern New York State (where I am).

  1. Jenny says:

    Have you ever heard of using diatomaceous earth to combat them? I read a bunch about it last year and was planning on try that this year with my Japanese beetles. I’m not sure when to put it out, but a local earthworm farm sells organic batches of it…..

  2. Tori Matton says:

    Exactly what kind of lilies are you talking about? Asiatic? Daylilies? Lilies of the valley? I’m all ready to go out and squish, but wondering where to start – mine are looking okay in Zone 7 – Maybe we don’t have them here…wishful thinking?

    1. Margaret says:

      Welcome, Tori. True lilies, genus Lilium, not the ones whose common names include lily (of the valley, day, etc…). Sorry not to be clear about the beetles’ current range, which is 6 Canadian provinces and throughout New England, lately in New York State…so we shall see where they go next.

  3. Marilyn Wilkie says:

    A friend and I were pulling up sod in preparation for a new bed for roses. We were happy to see tons of earthworms but not so happy to see numerous grubs. I took great pleasure in “popping” the grubs between my fingers – rubber gloved of course. Disgusting right? haha

  4. Deborah says:

    I haven’t seen them yet here (Oneonta NY) in my garden but have been on the look-out. I love Marilyn’s comment about popping grubs; be careful not to pop them into your face, which I have done before. Yech! These days I share grubs and even a few delectable worms with my 4 chickens. The steps out of my way are worth it to hear their approving clucks.

  5. Marilyn Wilkie says:

    Deborah,
    I was actually thinking of getting a couple of chickens to house in our new fenced raised garden area. It’s 28′ x 28′ x 40′ x about 30′ or so. Do they eat the adult Japanese beetles too? I plan on using the old drop them in a soapy mix early in the morning trick now. We had chickens when I was a child. We haven’t seen any of those lily beetles in our yard yet.

  6. Deborah says:

    Oh yes, chickens LOVE Japanese beetles. I don’t bring beetles to them since they would just fly off in the meantime, and the girls aren’t that interested in my squashed or soapy remains. But the fence on one side of the chicken yard is planted with raspberries, which attracts lots of Japanese beetles, and the girls enjoy them.

  7. Andrew at Garden Smackdown says:

    Ugh… I really think they’re the grossest pests out there. I discovered last year they like Chinese lanterns too (Physalis alkekengi, not the paper kind), though they just put a few holes in it while they’re on the hunt for lilies (which I gave up on; not enough time to hunt and pick).

  8. bavaria says:

    I’m looking at my cordless hand vacuum and thinking, hmmmm…..
    has anyone used that for sucking the little varmits off the plant?

  9. ayo says:

    The lilly leaf beetles did lots of damage (and made me a little nauseous) last summer in my Berkshires garden. I’m a weekend resident, wo they were able to get way ahead of me –picking and squishing alone wasn’t enough. Heartbreaking to see the damage! I hate to use sprays, but broke down and used neem oil, which controlled things a bit better. We’ll see if they are as voracious this year—haven’t seen beetles yet, but my lillies haven’t emerged yet either. I have (had?) tons of lillies and hope that last year’s uninvited guests haven’t done so much damage that I lost them. Keeping fingers crossed–It’s been a rough year and purchasing lots of new lilly bulbs and plants is not in the budget! Sigh….

    1. jim says:

      You had luck with the neem oil? I tried it before in my western MA garden and didn’t really get decent results. I just go with the pick and squish. And Sat. while I was tidying the garden I found one.. Already?!..arrrgghh

  10. Marilyn Wilkie says:

    Ayo, so sorry to hear of your troubles with the lily leaf beetles. It sounds like a terrible pest to have to deal with. I will be on the lookout here for them. I hope that you didn’t lose all of your plants from last year.

  11. Molly B says:

    A neighbor who has beautiful gardens and who uses no chemicals suggest holding a container under these beetles so that they will fall right into the soapy water and never makes it to the ground. Great for eye/hand coordination.

  12. Doug says:

    Well that was timely! I was just given a martagon lily (yes that’s true) and I noticed a handsome red beetle on one leaf. I somehow knew (having retained something from reading this blog with my morning tea):
    Q: “Is that a . . .LILY LEAF BEETLE!?!”
    A: “YES — Kill it!”
    [I don’t like killing anything, but for you, LLB, I made an exception, sorry.]

    Thank you Margaret (once again).
    (The incident described happened quite close to your garden).

    1. Margaret says:

      @Doug: Hopefully it was not an escapee from my garden who came to nibble at yours!

      @Jayne: I don’t know how they find us…radar? :)

  13. Jayne says:

    I’ve already started my campaign against them – the second my martagon lilies emerge, I am at them with (gloved) fingers – squishing away! I blamed their appearance on a big box store (wont mention any names) when I planted a large group of bulbs. COuld they have come in on that source? Another good reason to buy local if you dont already have them. Too easy to spread bad pests!

  14. Laura says:

    Guess what I spent a good part of the day doing? Thank you Margaret for your timely post and Jayne for your suggestion about wearing a glove- it made the job much easier.

    On a more delightful note, I saw my first hummingbird of the season at my flowering quince. Very nice.

  15. sundevilpeg says:

    Eeeek! Thanks for the warning. I have many lilies at present – Asiatic, Orienpet, etc – but this new marauder hasn’t reached us yet (upper Midwestern US). Wonder if they are also fond of Alliums, as they are relatively closely related to the lily family?

    1. Margaret says:

      Welcome, Sundevilpeg. No, not out your way (and no, not interested in Allium, thankfully — those onion relatives still seem to be pretty much pest-proof here). I never had the lily beetle till about two years ago (nor the Viburnum leaf beetle — which has shown up here, too lately). UGH. See you soon again, I hope.

  16. gayle says:

    When I find grubs I take them over to my blue bird feeder and give a yell out to the blue birds to “come and get it”. They LOVE the grubs and I LOVE seeing the blue birds!!

    1. Margaret says:

      Welcome, Gayle. I love this approach…helping the food chain along just a tad. :) See you soon again, I hope (and no bluebirds here in the garden so far this spring…everyone else, but no bluebirds).

  17. nora says:

    I didn’t realize that I should patrol my garden early in the season for the lily beetle – thanks for the warning. I live in Ontario (one of the six provinces affected) and they first appeared in my garden in July of last year. In the nearest, town about 10 miles to the south, these beetles have progressed enough to eat the lily leaves down to nothing. Here’s to early vigilance!

  18. Marilyn Wilkie says:

    Chiot’s Run, I pretty much have the same attitude about bugs as you. Last year I was only plagued by Tobacco hornworms (with the red horn), Tomato hornworms (without the red horn). Japanese Beetles and mosquitoes. I picked off and drowned the hornworms, though the plants still produced way too much fruit for us anyway. They are a beautiful worm!! Though scary. But the Japanese Beetles I just detest because they eat the buds of my roses before I even get to see the blooms! Disgusting! The mosquitoes were just horrible and I ended up buying a head to toe net suit in order to work in the garden in August.

  19. Lib Dornbush says:

    I have discovered that red lily beetles do not like cinnamon at all. Last year I sprinkled a goody amount of cinnamon all over each clump of emerging lily buds, then went to Ireland for two weeks, during which time it rained copiosly and the beetles got a bit of a head start. This year I have sprinkled the clumps again as the buds, and the beetles emerge. By the next day there is no sign of beetles. I expect I shall have to repeat this after heavy rains, butit’s a lot easier then the daily pick and squeeze! It’s also quite inexpensive; a good bag at the Bulk Barn cost me $2. 40.

  20. Bianca says:

    Hey Everyone,

    Well I have a huge flower garden with many
    different Lilly’s growing in it and I took a Saturday
    washing the Lilly’s leave and the flowers with neem oil and sunlight dish detergent and after it dried I took the neem oil and wiped all the leaves and stems ….. my Lilly’s was red beetle free for almost 2 months. if it didn’t rain and I didn’t have to water the plants it would of last longer but it washed off so I repeated my steps and hope to be free for the next month or two……

    it’s a bit of work but it sure worked well..also gives you a head start at squashing the ones around…

    I hope it helped….

  21. Bianca says:

    To: Lib Dornbush

    I really am going to try the cinnamon powder
    on them and I’ll be back to leave an update and
    I’m really excited to try this… I live in Calgary and started noticing those bugs last year for the first time…
    Thanks.

  22. E Greg says:

    Hi Margaret
    I was very dismayed yesterday to find my precious toad lilly was infested with lily beetles which are NOT supposed to bother toad lillies! I saw the little beggars!
    The leaves look like swiss cheese! I had great difficulty locating toad lilies in my area so I am very anxious to protect them if its not too late? I lost all my other lilies to this problem. Any hope of saving them as insecticidal soap does not seem to work?
    thanks
    E

    1. margaret says:

      Hi, E. Greg. The problem is — as they say — nobody got the lily beetles or their larvae to read the book about what the pests do and don’t eat. I think this newish-to-many-of-us pest will expand its dining choices gradually, and no wonder that another relative of the true lily is seeming tasty. Tricyrtis are not so commonly grown, so no wonder few people have posted online about it being bothered, I suppose. So sorry.

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