Friday, May 30, 2014

Scarlet Lily Beetles: Know the Enemy - The Definitive Guide to Hand Cleaning Your Lily Patch


I consider myself a first rate search and destroy machine when it comes to the scarlet lily beetle.

Not that they are hard to find.  A fantastic shade of red, they stand out like Xmas lights when they are perched on the top of a leaf in preparation for flight.  And they are eager to fly, unlike many beetles.







Imagine my shock when several years ago they moved into my NE Connecticut county.  I have mentioned how at first I was delighted with these jaunty little fellows.
Below:  Beautiful, aren't they?






Then they ate every asiatic lily I had to death...leaving behind only the tiger lilies which grew faster than the larvae could eat.  The plants looked awful, but not dead. The patch had a zombie appearance with tattered foliage sickly waving in the breezes.

The good news is you can control them by regular handpicking IF your patch isn't big. Mine is only about 10 feet long, on both sides of a walk, with only two or three plants deep on a side.  

After two years of horrendous numbers of beetles I started handpicking seriously.  After one season I noticed a difference but the next year was still very active.  This is the 3rd year of thorough picking and the numbers are small!   They will always be here though because they fly in from some distance. 



On average I only get less than a half dozen of mature beetles a day at the beginning of the season.  One day  in the first onslaught I did get 9...but that is unusual.  Compare the minor hassle of picking beetles  to the advice I found that "if you have the beetles in your area you might as well forget about growing any lilies"!!  Now in the end of May I only get a few a day.  The new June crop is coming though...they are pupating in the soil as I type if I missed any.


Adult beetle hunting:

Start the hunting season as soon as your lilies show.  Mine were only two or three inches tall when I noticed the first beetle.

Their first line of defense is the old stop, drop and roll.  When severely alarmed they let go and slide down the leaf, sometimes landing in the leaf axil where you can get them.  However, if you are hesitant to hurt the foliage too much they may have a moment's reprieve and do some fancy footwork to get out of there and drop to the ground where they take advantage of their black underside and role over and become invisible!!



Now, I have not scientifically tested this statement, but if one drops to the ground you can't find it 95% of the time.  If you wait around, in about 5 minutes you may spot it walking towards the plants.  I should think there would be a better chance than 5% to land shiny red side up....thats why I assert the damn things have an effective strategy against hunters that aren't put off by their snazzy "don't-eat-me-on-pain-of-poisoning" red elytra!!

My hunting technique is to first eyeball your whole stand of lilies for the mating pairs who are indiscreetly boffing in public (most pick a more private under leaf boudoir).  Also you will find the ones standing on their little patent leather shod tippy-toes getting ready to launch in the air.  Go for the air boys first, bringing your hands quickly to the spot with one over and one under the leaf and scrape the little dude off his perch.  Toss to ground and quickly squish.  The mating pairs are approached in a similar manner...don't forget the underneath hand as these pairs fall off most often.

If the mating pair break up, go for the one not in the leaf axil first.  Leaf axil sitters can be crunched by gently squeezing leaf from behind later, although I get them out of there, not taking any chances.

On warm days you can go back in an hour and clean up adults again.  Everything slows down on cool days so you can lower your vigilance somewhat.

Egg and larva patrol:



This is where I can save you some time. You sort of triage the patch.

First, if you found a mating pair, look around there more closely.
Second, if you note a peppering of itsy-bitsy black beetle poop that is more noticeable than usual, look there.  If beetles have been hanging out somewhere for any length of time they were probably mating.

As the season goes on you will have a lull in beetles, but they will return full force again in June.

Egg and larva checks and removal:

To quickly check for eggs start low on the stem and run the foliage up through your circled thumb and forefinger.  Look at the underside as you go.  You will see the eggs, or feel eggs, or see them on your fingers and go back and find them.  This only takes a few seconds to check, and a few more to scrape off the eggs.  Older eggs turn dark brown, but the new ones stand out.


In spite of everything you will miss a couple.  Sometimes the eggs knock off the leaf and I think they fall down into a leaf axil.  The chewed up leaf is easy to spot but don't miss too many days in a row as these things work REALLY fast!  If you see this transparent stripped from underneath leaf condition the larva will be there.



They are nasty little buggers.  Covering themselves with poop they are icky to scrape off.  I do it when they are young and smear off my fingers on the sidewalk :-)  When they are a bigger poopy blob I have to admit I pinch off a bit of leaf (it look awful anyway) and step on it.  Nyar-har-har...



Sounds odd, but I feel the plants appreciate the care.  One certainly gets to know them well!
For more information go to the following site.  Good info on parasitoid controls.  I tried the Neem route one year but I really dislike the smell!  It registers as garlic to my nose, not a scent I want in my flower border.

Following from - http://extension.umass.edu/landscape/fact-sheets/lily-leaf-beetleHistory

The lily leaf beetle (LLB) is native to Europe and was discovered near Montreal, Canada in 1945. Its damage was limited to the Montreal area for decades, until discovered in the United States in 1992 in Cambridge, MA. It is thought that LLB arrived in a shipment of lily bulbs from Europe. Since then, LLB has spread throughout much of Massachusetts and is working its way throughout New England. Lily leaf beetles are strong fliers and are also moved from one area to another on host plants. Both the immature stage and adults cause damage by eating the leaves and buds. Adults and larvae are commonly found together devouring lily foliage. Often, they consume all the leaves leaving only bare stems.


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