Scarlet lily beetles (Lilioceris lilii) is the newest ailment for lilies in our area and could likely be the thing that would even destroy all lily growing potential. Over that last 20 years they have been migrating across the county from Montreal, an apparent inadvertent import from Europe.
Scarlet lily adults emerge from the soil surrounding the base of lily plants that they have overwintered voraciously hungry and ready to mate. They come out in early spring just as the lilies are emerging. Any one female can lay as many as 250 eggs.
You can spot that they are around by:
- Multiple unsightly holes in your lily leaves
- By their bright red rectangular shaped body (slightly larger than a lady bug) and rather large black antennae
- They love to hang out on the bottom side of the leaves and dine upside down. When they detect any slight kind of danger, they drop off of the leaf in a back flip, landing on their backs with their black underbelly facing up – making them next to impossible to see.
There are few chemicals that are effective against Scarlet Lily Beetles, so the most effective way is to go out regularly, like every 2 or 3 days, and catch them manually. This requires resolve and diligence, but this war can be won.
How to catch the adults:
- Because of the back diving, this is a technique that is wonderfully effective: Very gingerly, without shaking the lily plant, hold a sealable container filled ½ full with soapy water or vinegar against the stem below the beetle and knock the leaf the beetle is on – it WILL back flop right into your container. And drown. Yay!
– Keep scouting for adults all summer, they stay around until fall.
Ridding yourself of the eggs:
- Scarlet lily beetle eggs are easy to detect. They are bright red, laid in an impressive line on the undersides of the leaves. They hatch in about 2 weeks after being laid.
- Pick off the leaves with the eggs and put them in a sealed plastic bag so they have no chance of surviving.
Getting rid of juveniles:
- As the juveniles grow, they cover themselves with their own excrement as a way of camouflage and making themselves less desirable for birds (no kidding!).
- As with eggs, the best way to take care of this is to pick off the leaves that are hosting them and add them to your sealed container with the soapy water or vinegar or a plastic bag, so they will die.
In the autumn, lily beetles tend to take flight and they do fly well. That is how they have spread from garden to garden, town to town, and province to province. Be encouraged to do your best to rid our gardens of this very scary beetle!
Sources: gardeners.com, umaine.edu/publications/24 50e, northscaping.com, calgary.ca