A bug to strike fear in the toughest of lily growers and gardeners!
We are fortunate enough to grow in an area where the lily beetle has yet to make an appearance, and we are extremely thankful. We have much reason to be so thankful as this dreaded little beast can do an incredible amount of damage in a very short time!
There had been no reports of this beetle in the province of Alberta until spring of 2003, when a member of the Alberta Regional Lily Society alerted the Society to the fact that he had ordered lily bulbs (from a large, well-known, reputable mail-order nursery out of Ontario) that arrived complete with beetles. Since the company is so well known and surely has a large customer base here in Alberta, we can only assume it is just a matter of time before it becomes a problem here, which is a terrible shame. I cannot help but feel the company in question should have been more careful in their inspection of bulbs they purchase for resale before distributing them to their customers - it is of utmost importance that bulbs be clean and free of soil and pests to prevent problems that can have such detrimental effects on gardens for many years to come!
I was contacted by a customer in Ontario in 2003, who needed help to battle this pest before they destroyed his beautiful lily gardens, but I was unable to help as I'd never had to deal with the problem myself. He had been told by a local garden centre to use CYGON (a very powerful and potent chemical pesticide). I was familiar with CYGON and agreed it's potency and systemic effects were favorable for use on this pest. I suggested he contact the company which makes the product to see if it could be used on lilies without damaging the bulbs or growth. Their reply was positive, and he was nice enough to forward the reply to me. Here is what they suggested for treatment:
- 4 teaspoons CYGON per gallon of water for use as spray on the lily stems
- 4 tablespoons CYGON per gallon water for use as a soil drench
PLEASE NOTE THAT CYGON IS NO LONGER AVAILABLE ON THE CANADIAN MARKET, BUT WE LEAVE THIS INFO FOR YOU JUST IN CASE YOU MAY HAVE SOME IN YOUR GARDEN SHED YET - IT WAS A VERY POPULAR CONTROL FOR BIRCH LEAF MINOR ON TREES IN THE PAST.
This is a systemic pesticide, which means the plant absorbs the chemical and then the pest digests it along with the plant material as they munch on it and then die. Systemic controls have long lasting effects and require less frequent treatments, they also take a few days to be completely absorbed by the plant. Control should begin in 4-10 days and the treatment should be applied every 4 weeks. Be sure to spray when no wind is present, and only in early morning or late evening, never spray in direct sunlight. I cannot caution you enough on using safety precautions when using this product - it is extremely potent and overuse, whether by mixing too strong or application too frequently can cause severe damage to the plants. Protect your skin and wear a mask at all costs! This product is commonly used for treatment of Birch Leaf Miner on Birch trees here in Alberta, and is considered the most effective control.
I should add that immediately upon hearing that it could be used on lilies, I mixed a solution of it at the required rate and applied it to a large clump of lilies as a soil drench in order to test for damage to the plants (I was a bit skeptical that there would be no leaf scorch or burn as in every instance where I have used it there was visible plant damage, regardless of type of plant or tree). It was applied on an early summer morning and the lilies did not suffer a hint of visible damage.
HOW TO PROTECT YOUR GARDEN
The best thing to do to protect your garden if you reside in an area where it is not yet present, is to ensure you buy bulbs from reputable sources, and that they are COMPLETELY free of all soil. That means they must be washed! If you are in doubt as to whether they have been, wash them yourself. Soak them for 20 minutes in hot water with 2% bleach added, then rinse them off with water only before planting.
- Buy bulbs from reputable sources who clean their bulbs before shipping.
- Do NOT plant bulbs from sources when they arrive with soil still attached to roots or the base of the bulb.
- Wash them yourself if in doubt.
- Avoid buying potted lilies from grocery or department stores, even some floral shops. Many of these sources import potted plants from outside the province and country. Don't take their word for it if they tell you they are locally grown!
- Consider where you are buying from before ordering - does the area your ordering from already have the beetle established or known to be present? Does the supplier wash and clean their bulbs before packaging? At this time (December 2016) Atlantic Canada, Ontario, Manitoba, along with Alberta are known to have the beetle wide spread, as do most locations across the USA. Central Saskatchewan saw first reports of its presence in 2015-2016.
Chemical controls include Rose & Flower spray, Orthene or dust containing carbaryl (Sevin), methoxychlor, or Malathion. A systemic control would be the best, as the larvae and beetles would then die as they eat and you don’t need to keep applying it. The previously mentioned chemicals are not systemic however, and need to be reapplied every 5-7 days. Cygon is effective as a soil drench systemic but no longer available. There are very few chemical choices in Canada any longer as many have been removed from the market.
Organic controls include Rotenone and Neem oil. The gardener I spoke with said pyrethrum (Rotenone) had no effect. Recently (October 2010), I learned from John Rempel of the Manitoba Regional Lily Society that pyrethrum was in fact effective, but must be at least .5% strength. Any product containing this strength of pyrethrum will be effective. Safer's End All was suggested and is commonly available, although the label states .2%, buy the concentrate and mix it double strength. Neem oil is very effective according to an internet search, but only kills larvae when it contacts them, so you must spray them directly and be vigilant about it. It only repels the beetles, forcing them to move on. (People I have spoken to say Neem was an expensive option that did not work at all.)
Recently (June 2011) a very considerate Dawn Leggett sent me an email about the control method she uses, and she says it works! She lives in an area where the beetle has been long established and since her method is non-invasive and does not use chemicals I think it is very worthwhile to try. Please also be sure to read the reference card I sent out with all orders a couple years ago as it also outlines specifics on controlling this pest. Read on...
Dawn L. - In the May 2011 issue of Garden Central, I read Mary Louise Miller's request for help fighting lily beetles. My good friend Bill taught me how to deal with them: TALCUM POWDER. Yup, ordinary talcum powder. Baby powder with talc, not with cornstarch, works very well. I buy the largest size and poof it beside the lilies and on the ground around them. I begin in the spring with the first sign of growth, then apply it regularly afterwards. It works on all stages of the beetle. It is cheap, safe for humans and plants, is biodegradable and works. I think it suffocates the critters because it is such a very fine powder. It also works on ant hills. Just cover the top of the hill and block the entrance to the nest. Hope this idea helps restore lily plants and sanity to those trying to enjoy these glorious plants.
August 10, 2011 - Debra B. wrote this: I used Safer's Natural Garden Fungicide (concentrate). I used 3 tablespoons in 1 litre of water. I was prepared to double the dose if it did not work the first time. I went to the Wikipedia site to look at all the stages of this insect. http://en.wikipedia.org/wiki/Scarlet_lily_beetle. At the time this fungicide worked I believe most of the insects were in stages 2 and 3.
August 17, 2011 - Dave W. from Edmonton area sent me a note saying he tried Dr. Doom House & Garden Spray.....and it worked! He says within 30 minutes the beetles were dead, and the lilies suffered no damage. He also informed me that Sevin/Carboryl was toxic to bees, something I never knew or had forgotten if I did. Please keep this in mind when choosing your 'weapons' as the bees are more than important to our planet!
May 2015 - A fan on our Facebook page noted that the Talcum powder did work, but KING Potato Dust worked even better in her opinion. She also commented on how it worked, by smothering the beetles as they breathe through their underbodies and the dust literally smothers them.
Thank you Dawn, Debra, Dave and everyone else for sharing, I am certain you will have restored sanity to many a gardener with these control options and we all truly appreciate it!