Scarlet lily beetles (Lilioceris lilii) a new pest to watch out for in the lily garden. They affect Asiastic, Oriental, LA, and Martagon types of lilies. Scarlet lily beetles do not bother Daylilies (Hemerocalis). Over that last 20 years they have been making a steady migration across the county from Montreal, folowing an apparent inadvertent import from Europe.
Scarlet lily beetles over winter in the soil surrounding lily stalks in the fall. They come out in early spring just as the lilies are emerging. The adults are hungry and ready to get on with life and mate. Any one female can lay as many as 250 eggs.
You will know Scarlet Lily Beetles are around if you see:
• multiple unsightly holes in your lily leaves.
• their bright red rectangular shaped bodies (slightly larger than a lady bug) and rather large black antennae.
Scarlet Lily Beetles love to hang out upside down on the bottom sides of the lily leaves. When they detect any slight danger, they drop off of the leaf backwards, landing on their red backs with their black underbelly facing up – an impressive protective mechanism because it makes them next to impossible to see in the soil.
There are few chemicals that are effective against Scarlet Lily Beetles, so the most effective way to catch them 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 their predictable back flipping, this is a technique that is wonderfully effective:
o 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.
• Keep scouting for adults all summer, they stick around until fall.
Getting the Eggs:
• Scarlet lily beetle eggs are easy to find. They are bright red, laid in an impressively straight line on the undersides of the lily leaves. The beetles hatch about 2 weeks after the eggs are laid.
• Pick off the leaves with the eggs and put them in a sealed plastic bag so they have no chance of surviving.
Death by suffocation.
Getting the juveniles:
• As the juveniles grow, they cover themselves with their own excrement as a way of camouflaging and making themselves less desirable for birds (No kidding no sane bird would eat that!).
• As with eggs, the best way to take care of the these beetle babies is to pick off the leaves that they are on and add them to your above sealed container with the soapy water or vinegar or you could just put these a sealed plastic bag, so they will die.
In the autumn:
• Lily beetles over winter in the first 2-3” of soil around the stalk of the lilies. Loosen up the soil vigorously after the first few frosts to disrupt their napping and you can catch a few more that way.
• The more beetles you catch on this side of spring the better.
• Lily beetles tend to take flight this time of year 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 agressive beetle – you have to be diligent but you can do this!
Sources: gardeners.com umaine.edu/publications/2450e, northscaping.com, http://calgary.ca