I did win the battle against the scarlet lily beetle, which is also known as the lily leaf beetle (Lilioceris lilii). This is an insect that eats lily (Lilium) leaves, giant lily (Cardiocrinum) leaves, and fritillarias (Fritillaria) leaves. leaving them looking like they’d been put through a blender. I used to hate them so much and consider them the worst garden enemy, but I haven’t seen one in my gardens in three years!
The easy fix was to pull up and compost all of my lilies and fritillarias. Since the beetle now has nothing to eat at my house, it has moved on to a better place, like my neighbor’s house where there are still lots of lilies. I wish my hammock was higher so I could see over the fence and watch her bob back and forth every day for an hour, squishing and spraying. I already told her to stop complaining, become a laid-back gardener, and especially stop feeding her enemy, but she keeps saying, “It really isn’t that much work,” and then she keeps complaining.
Lily beetles are beautiful but destructive insects that can quickly defoliate and damage lilies and fritillarias. If you grow these prized flowers, you’ve likely battled with lily beetles. While hand-picking and insecticides provide some control lily beetles inevitably return each year. Fortunately, there are several highly effective ways to get rid of lily beetles for good.
Understanding the Lily Beetle Lifecycle
Knowing the lifecycle of lily beetles is key to timing control methods correctly.
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Adult lily beetles emerge in spring and lay orange eggs on the undersides of leaves.
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After about a week, the eggs hatch into larvae that cover themselves in black excrement as camouflage.
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There are often two or three generations per year.
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Lily beetles overwinter as adults in plant debris and soil.
Physical Removal Methods
Hand-picking adult lilies and larvae is effective for small infestations. Check plants daily in morning when beetles are sluggish. Crush beetles or drop in soapy water. Remove eggs by turning over leaves.
Place newspaper below plants to catch falling beetles. However, hand-picking must be extremely diligent to control large outbreaks.
Knocking Beetles into Soapy Water
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Fill a sealable container halfway with soapy water or vinegar.
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Very gingerly hold the container against the lily stem below the beetle.
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Knock the leaf the beetle is on and it will backflip into the water and drown.
This is faster than hand-picking when populations are high.
Organic Sprays
Apply organic sprays regularly to deter lily beetles:
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Neem oil – effective applied every 4-5 days
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Pyrethrum insecticidal soap – must apply daily
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Dish soap or detergent – only kills on contact so repeat applications needed
Sprays are less effective on larvae than adult beetles. Avoid harming pollinators by spraying early morning or evening.
Companion Planting
Interplant lilies with pungent herbs like onions, garlic, and pyrethrum. These can mask lily scents and deter beetles, but results are mixed.
Removing Lily Plants
Eliminating lilies entirely will eradicate lily beetles. Replace lilies with daylilies, which are unaffected by beetles. Lily bulbs can attract beetles, so discard or seal in plastic bags before composting.
This drastic but foolproof approach is suitable if you grow lilies in containers or small garden areas. It also prevents the spread of viruses transmitted by lily beetles.
Biological Controls
Natural predators in Europe and Asia keep lily beetle populations in check. Researchers are investigating introducing select predators to North America as safe biocontrols. Until then, encourage native predators like birds to eat beetles by providing habitat. One gardener reported a catbird voraciously eating lily beetles!
Preventing Reinfestation
To prevent lily beetles from migrating back into your garden after removal:
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Use floating row covers on lilies in spring before beetles are active.
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Apply adhesive barriers like Tanglefoot around lily stems.
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Introduce beneficial nematodes to soil to parasitize overwintering beetle larvae.
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Remove plants debris where beetles shelter over winter.
The Nuclear Option: Total Eradication
For the most hardcore of lily lovers willing to temporarily sacrifice their plants altogether, here is a scorched earth method to completely eliminate lily beetles from your property:
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Remove and destroy all lilies, fritillarias, and related host plants. This deprives beetles of food.
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Apply pesticides frequently for an entire season to kill off adults, larvae, and eggs. This breaks the reproduction cycle.
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After a full year with no host plants and heavy pesticide pressure, lily beetles will be eradicated.
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The following season, tightly screen all new plantings with floating row covers until any residual beetles migrate away or die off.
This approach requires patience and sacrifice but is the only sure way to permanently eliminate severe lily beetle infestations. Going nuclear on lily beetles protects your precious lilies in future years when you replant them.
While lily beetles are difficult to deter, several control methods used diligently can provide relief from these destructive pests. Removing lilies completely and preventing reinfestation is the only permanent solution for heavily infested areas. With persistence, you can reclaim your garden from the scourge of lily beetles.
Plenty of Tips… That Don’t Work
I tried mightily to control the lily beetle by other means. I even succumbed to methods best described as folk remedies. Here are some of things I tried:
The best way to get rid of the beetle, but you have to do it every morning as early as possible, while it’s still a little sleepy (most insects are at rest in the morning). When you start too late, when it’s more active, it will quickly drop to the ground when it sees you coming and turn over to show you its black underside. It then plays dead, making it almost impossible to see against brown earth.
You can either squish it between your fingers or drop it into a pail of soapy water when you catch one. Personally, I like squishing better, but that could be because I’m picky. You also need to get rid of the gross larvae (they cover themselves in their own waste to scare off gardeners, I’m sure!) Also, go over each plant leaf by leaf and turn the underside of each leaf up to see the orange eggs that are hidden there.
If you keep doing these things every day, the population will eventually go down. But just when you think you’ve won, the second generation of beetles comes in, and you have to start all over again. And yes, there is even a third generation at the end of the summer!.
You can keep your lilies mostly whole if you keep picking them by hand, but… what a lot of work for just a few flowers!
I was told that coffee grounds were perfect tool for discouraging lily beetles. They told me to put them around the base of my lilies and the smell of coffee would keep the beetles away. Result: a total flop. The beetles kept eating my lilies like I hadn’t done anything, and now all of my pretty, fragrant lilies smelled like coffee, which I hate!
Several gardeners and (former) friends told me to plant garlic, onions, and pyrethrums next to my lilies, so I did. The lily beetles just laughed at me.
I think I tried everything that wasn’t against the law or very dangerous, like making my own nicotine spray, which can kill you quickly and painfully if you breathe it in. It has rhubarb leaf spray, garlic spray, and hot pepper spray, with or without soap to help them stick. The results were mostly abysmal. I simply saw no difference.
Neem oil was the most effective spray treatment. By treating every 4 or 5 days, I seemed to get some control. Insecticides that included pyrethrum, a natural insecticide, also worked… for a while. I had to apply them daily for results. Insecticidal soap and dishwashing liquids worked too, but only if they actually touched the insect. And more daily sprays were required.
Every time, I had to do the treatment over and over again, and I don’t want to spend my time spraying insecticides. I also worried (and still do) a lot that I might be killing good bugs (like bees) as unintended consequences.
I really got to test this one, as I live in a very cold climate. I was told that lily beetles would die when the ground freezes very deep because they spend the winter there. If so, more must be flying in from somewhere else, because there are already a lot of them here after even the coldest winters. Last winter, it was -22?C (-30?C) for more than a week, and the ground frozen to a depth of 2 feet (7 m). Yet I can still see my neighbor hand picking lily beetles every single morning, rain or shine.
What is the Scarlet Lily Beetle?
There’s something quite beautiful about it. The top of it is long and bright orange-red, and the bottom is black. It was accidentally brought to Montreal in 1942 from Europe and Asia, where it seems to have spent 50 years getting used to the weather. In the early 1990s, it suddenly started to spread again. It is now widely distributed through New England and all of Eastern Canada and continues to spread. If you don’t have it yet (lucky you!), you probably will one day.
How to Get Rid of the Scarlet Lily Beetle Using Organic Control
FAQ
What kills lily leaf beetles?
Do coffee grounds repel lily beetles?
What do you spray for lily leaf beetles?
What is the best insecticide for red lily beetle?
How do I get rid of lily leaf beetles?
The best way to get rid of lily leaf beetles is to not allow them into your garden in the first place. Before you purchase new plants, check them over to make sure that they do not have any beetles or larvae on them.
Do lilies get rid of beetles?
This home remedy is widely used in all kinds of gardens to help control all kinds of pests. The reason is simple—it works! So, sprinkle some diatomaceous earth at the base of your lily plants as well as on the shoots. The beetles will die not long after crawling through it.
How do I get rid of Scarlet Lily beetles?
Combatting Scarlet Lily Beetles centers around prevention and elimination as we focus on the different life stages. Careful inspection of the lilies during each phase of the growing season is vital to successfully controlling Lily Leaf Beetles.
How do you get rid of lily beetle grubs?
Where this isn’t feasible or practical, you can control them by spraying a lily beetle insecticide onto affected plants. The best ones to use are systemic insecticides. Lily beetle spray tends to be more effective against the grubs than the adults, which can fly in from neighbouring gardens.
