Red Lily Beetle? Yikes! Here's your battle plan.
![Red Lily Leaf Beetle. They mate 2 times a year and their population can grow quickly. Adults overwinter underground to start a new generation first thing in spring. Red Lily leaf beetles, mating.](Images/Lily-Beetles-mating.jpg)
Lily beetle feeds pretty much only on plants in this genus, so you can focus on monitoring these plants only with the following control measures. (note: Daylilies are the common name for the Hemerocallis family - nothing at all to do with true lilies other than the resemblance of their flowers).
![The first tell-tale sign that Red Lily Beetles have found your garden! Start your battle plan now or the population will quickly grow to do much more severe damage. The first signs that Red Lily Beetles have moved into your garden.](Images/Lily-Beetle-firstyear.jpg)
Not an easy pest to control if you grow Oriental Lilies. Here's your battle plan!
This devastating garden pest attacks and lays its eggs on, Lilium species mainly- the stunning bulb Lily family of plants. Lily Beetle (Liloceris lilii) was first discovered in North America in 1992. Most likely they hitch-hiked in a shipment of bulbs from overseas. It has since spread throughout the northeast to the complete demise of gorgeous Lily beds everywhere. For years collectors tried product after product for control, but the Lily Beetle's tenacity was no match.
![Look on the underside of your Lily plant's leaves soon after they leaf out in spring. Look for lines of reddish eggs. A simple swipe of your gloved finger is all you need to do to kill off the first round of population growth! Lily beetle eggs - watch for these on leaf undersides soon after the plants leaf out in spring.](Images/Lily-Beetle-Eggs.jpg)
Identification: Adult Beetles are easy to spot - bright orangey-red, square-ish, and about 1/4" long.
![Lily beetle larvae. They look like little blobs of slimy poop! Lily Beetle larvae, chewing on a leaf.](Images/lily-beetle-larvae.jpg)
Life Cycle: Adults over-winter in the soil's surface layer, emerge in spring (in sync with the emerging lily foliage), and immediately mate. Early to mid May you'll find adults tucked into the leaf joints, often in pairs, busily mating. Soon after mating, females lay brownish-orange eggs on the undersides of foliage that hatch within 4-8 days. (Mid to late May, routinely check the undersides of leaves for an orange line of clustered tiny eggs). This more or less brings us to early June here in the northeast, when you'll see the young larvae initially feeding on the undersides of the foliage, but later on the upper surfaces, stems, and buds. (If you where vigilant about getting the adults and crushing the eggs, you shouldn't end up with too many larvae.)
The larval feeding phase of their life cycle is the most destructive. They voraciously munch holes in leaves to
![Left unchecked, in 2-3 years Red Lily Leaf Beetle's population grows so large that virtually all the leaves on your Lilies are eaten and the plants weaken from lack of leaf surface to photosynthesize. Lily Beetle damage after a few years of being left unchecked.](Images/Lily-Beetle-leafdamage.jpg)
Each female beetle produces 250-450 eggs. That's a lot of lily beetles! Left unchecked they'll overrun and demolish any host plants in the vicinity within just a year or two.
Management: If you focus on the Lily Beetle's life cycle, it's easy to see when you can be
![Adult Lily Beetle and eggs. There's 2 generations per year, with adults overwintering to quickly emerge and lay eggs to continue the cycle. Lily Beetle adult and eggs](Images/lily-beetle-adult-eggs.jpg)
Avoiding the Problem: If you've grown Lilies successfully in the past without meeting this nasty pest, don't be too smug! With just one new un-inspected purchase the situation can change quickly. When purchasing new lily bulbs, or accepting a gift from a gardening neighbour, dunk them in a weak bleach solution for a minute and rinse them thoroughly, before they even get near your garden. ...and make sure the rinse water goes down a drain and not outside beside the garden hose! Remember, you're looking for bright red adults or slug-like larvae in the soil - not eggs, so they should easily rinse away if present. Inspect them thoroughly!
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In the case of potted bulbs already growing, dunk and rinse them nevertheless. The growing plants will be weakened, and may punish you by not blooming well the first year - but they won't die. Wash away all soil that's in among the roots using room temperature water, and also inspect stems and foliage thoroughly for eggs or young larvae - any adults likely dropped off the plant already. Even just one beetle that makes it into your garden can begin the ravaging cycle, so don't let your eagerness to get your new plants into the ground deter you from a thorough de-bugging first.
Even with vigilance, once you have Lily Beetle in your garden beds you've likely got them for good. Control is the best you can hope for. Focus on its life cycle so you know what to watch for, when. With a watchful eye, a battle plan calendar, and a gloved hand, you'll be able to keep their population down to a manageable level and continue enjoying your beautiful Oriental Lilies.
Good luck, and keep your gloved hand ready to pounce! Evelyn
©Evelyn Wolf, 2019. All rights reserved. contact for permission to use.