Birch leafminer, black turpentine beetle, Colorado potato beetle, gypsy moths, fall webworm, eastern tent caterpillar……..for the last two weeks we’ve been studying bugs in my master gardener class. I’m getting a little tired of them, but since there are at least 10 million species of bugs in the world and only a small number of them are harmful, it’s important to know about the bad ones. That way you can go after them without harming the ones that are beneficial or cause no problems. I thought it would be useful to post profiles of some of the most harmful/destructive New England pests, starting with the lily leaf beetle.
Now, a pest that destroys ornamentals might not be at the top of your list of the most harmful pests. But lilies are an important part of New England’s culture and landscape–New England would look a lot different in the summer if our lilies were decimated.
Description. The bright-red lily leaf beetle, Lilioceris lilii, is a pretty little European native that turned up in eastern Mass. in 1992–probably in a shipment of lily bulbs. These little guys (and gals) love to eat the leaves of lilies and fritillaria. In fact, if they’re not controlled, they’ll defoliate and kill them. Important: They only eat true lilies, those of the Lilium genus, including Asiatic, Easter, & Oriental lilies. No need to worry about your ubiquitous daylilies–those are in the genus Hemerocallis and are not true lilies.
Lily leaf beetles lay reddish-orange eggs on the underside of lily and fritillaria leaves, and because it’s the just hatched larva that cause the most devastation, here’s a few lovely photos.
On the right is the ugly & slug-like larva. On the left the larva is carrying its frass (entymologist-speak for poop) on its back, an unpleasant habit developed to protect itself from predators (such as pissed-off New England gardeners).
Control. Because it’s a European import, there are no native predators here. University of Rhode Island researchers have traveled to Europe, picked up some larva or parasitic wasps that prey on lily leaf beetles, and are currently introducing the wasp to the region. When this introduction takes hold (and it seems to be successful so far), then hopefully gardeners will be able to breathe a little easier.
In your home garden, patrol for them and pick the adults, eggs, and larva off your lilies, making sure you destroy them–try dropping them in a can of vegetable oil or water with a lid. The adults are easy to find because of their color, but if you drop one you’ll lose it because its underside is black. So you might consider putting white cloth on the ground if you’re going beetle-hunting.
I won’t tell you not to use pesticides on them. If you suddenly find that the lilies you’ve worked hard to cultivate are being destroyed, then you gotta do what you gotta do. But try other methods first if you can. And if you do go with pesticides, ask your local cooperative extension service or master gardener group to help you choose the appropriate one.
Photo credits: Lily leaf beetle by Wikipedia; larva with frass by UMass, larva by University of Guelph.
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I am doing illustrations for Stonewall Farm, a non-profit educational working farm, in Keene, NH…beneficial and harmful insects. Am curious about the parasitic wasp you described in your article. Does it have a name? Size? Do you know where I might find a picture? I enjoyed your style.
Hi Bob. I believe that URI was initially studying 3 types of wasps. One is called Lemophagus pulcher, there is a photo in this magazine, http://www.gso.uri.edu/maritimes/Back_Issues/back_issues.html. Go to Vol 41, Issue title is “BioInvasions.” In the sidebar of this issue, click on the article by Richard Casagrande and then click on Figure 5 to see the wasp close up.
I believe they have had some particular success with one called Tetrastichus setifer, I couldn’t find a good photo but you may be able to using Google Photos.
Can we trade jobs? Yours sounds great. Oh, I forgot, I guess I have to have artistic talent.
Good luck with your illustrations & thanks for visiting EFG.
thanks for your tip on the nasty red beetles that eat asiatic lillys. This is the 3rd year that they have trashed my flowers. I am happy to know what they are, finally !! Forgive me please, I had to spray pesticide on them with hope that it would kill them. They seem to be worse this year. Any other suggestations? Thanks, Cathleen, Warwick, RI
Hi Cathleen, in terms of ‘earth friendly,’ the best way right now to get rid of the LLBeetles is to pick them off and drown them. But that’s more timeconsuming than a lot of people want to deal with. On the lily leaf beetle fact sheet located here:
http://www.uri.edu/ce/factsheets/sheets/lilyleafbeetle.html, URI suggests the following insecticidal control. Note the preference for neem extract which is itself plant-based:
“The insecticides carbaryl (Sevin) and malathion are effective on adults and larvae. However, carbaryl is highly toxic to bees and malathion is also toxic to many non-target insects. To date, our material of choice for treating flowers is neem, an insecticide based upon extracts from the neem tree. Neem can be purchased at garden centers under the trade names Turplcx, Azatin EC, Margosan-0, Align and BioNeem. Neem kills larvae and repels adults. Neem is most effective on first instar larvae; it must be applied every five to seven days after egg hatch. The insecticide imidacloprid also provides effective control. It is available in several formulations from Bayer including foliar sprays, soil drenches, and fertilizer stakes.”
Thanks so much! Had thought the ordinary garden slugs were back for my hostas, which are thriving in the shade garden, but found only lilies being decimated. Now to get those darned bugs out of my garden! I didn’t think it would be so easy to find out about them. Never have seen them before, and I’ve been pretending to be a gardener since 1954.
…and thanks from me too. Out the door and on my way to work yesterday I saw brownish blobs on my lilies!!!!! My first thought was to pick and drown but the garden hose was handy and not wanting to be late for work, I sprayed the frass out of them! It is great having such good information at ones fingertips. Thanks again.
Ah-hah! So that’s what those nasty little black SOB’s are! And here I was thinking the adults were some type of assassin bug. It’s SOOOO good to be informed!
Thank you!
how do i get rid of these beetles my garden is infested with them. they have eaten all my lillies from bottom to top and none of my dahlias or daffodils came out this year.
This year I found them on my lilies in Greenville but these beetles arrived in southern Maine about 3 years ago. Do the japanese beetle traps attract them too? I shall try neem oil and hand picking.
I have been infested with them for 4 or 5 years. My children and I go on lilly bug patrol 2x’s per day, our prefered method of attack is pluck and stomp. I have found the dam lilly bugs as we call them hiding out in my hosta, and that is where I first see them in the spring. I am told that they were first introduced into the area from a local nursery in my town. so my hopes of ridding my garden seems hopeless. I cannot wait to see how well the wasps do. Thanks
I live in Pomfret Center, CT. We were infested with those nasty things (summer 2007). I wear rubber yellow gloves and just crush them with great satisfaction! Will try the neem oil this summer, as I know they will be back in our yard for the bounty of lilies we have.
I had these horrible pests last year, did not figure out what was going on til lilies were almost destroyed. This year I set out hunting them every day as soon as the leaves popped up. I did that for 3 wks every day and have not seen any now for 10 days. I tried neem oil and nasty stuff last year, only late at night to avoid bees, but it did not even touch them.
So far I vote for picking them off, but only if you have a limited amount of lilies and time to do it.
hi think it is the red leaf beetles on my plants of lillies from david in england
Here in northern MA we’ve tried the flower spray by Bayer and it is the only thing of many (natural and synthetic) that has worked extremely effectively on those little pests. Last year we tried only picking them off because we have tons of dragonflies and other beautiful beneficial insects that we didn’t want to put in jeopardy, but our lillies were virtually destroyed. Now we are back to spraying them carefully so as to not hurt other insects, but the deer have been feasting on them for the first time! So needless to say, we’ll not have many lillies this year!
I am in Ontario, Canada and have just discovered these nasty little creatures all over my lily. They have completely destroyed half of the plant, and the stocks that are still left are almost completely leafless. Thanks for the info and advice…i will break out my gloves and try salvaging what’s left of my lilies.
Well, we have these for the first time this year (2008) in Kent Heights area of East Providence. Everyone up and down the street is complaining about them, and my lilies look awful. Came on line to figure out what they are and what to do about them. I suspect the local stores will be having a run on Neem etc. in the next few days as I pass the word. It may already be too late for one of my lily beds; ugh!
Last Spring I planted about 6 different cultivars of Lillium, and they were a big hit. This year like proud little soldiers the bulbs were poking up and growing wonderfully. I was taken ill for March and April and really did not keep track of the garden. In June I noticed this awful attack on the lily leaves. Not until today 7/16/08 did I see any insects. At first I thought they were lady bugs. After a closer look I knew better. Your article above (especially the picture and life cycle information) was most helpful. These lilies were were hit pretty hard. I will spray them with Neam every couple of weeks. What chance of survival will they have…a good guess is fine of course. Hope you had a good time in North Carolina.
I just discovered these buggers in one of my lily patches this year and hate the destruction they have wrought. Have been hand picking adults, but was loathe to touch the frass covered larvae until the damage was done. Will hosing or heavily watering help clean them off? I’m just thankful they haven’t found my other patch.
oops, forgot to say, I’m in central Vermont.
So glad to have found your informative web site. Here in Ontario we are experiencing the invasion full on this summer. I did hand/ crushing picking right from early June and still have lovely display for our B&B guests, but now I will use the sprays too in the hope we can reduce the problem for next year. Many gardeners here are just discovering the little red devils for the first time.
I found red lily leaf beetles on my lilys today in Rochester, NY.
Just got thru picking about 20 of them off my lilies with my husband helping once I showed him what they were doing he found alot I hadn’t found. We also found some of their eggs so we trimmed those couple leaves off and put them in a cup of soapy water. I saw them for the first time last year and figured out they were eating our lilies. I also have found them hiding in my Hostas but I’m not sure yet if they eat them yet. I just noticed them hiding in the hosta’s today. I’m in Somersworth, NH. None of my neighbors seem to have lilies so I’m not sure why I have so many of them.
I’m going crazy picking those nasty lily beetles. My bucket of soapy water is the way I have been trying to control them. Last year they just about wiped out most of my precious lilies. This year spring came about 3 weeks earlier than usual, and my garden is infested with the buggers since mid-April. Insecticides are my last resort, but this year I may have to try NEEM. I’m just south of Montreal, in Quebec. I would have hoped that our cold winters would kill them, but they are very resilient.
Last year the darn things made my lilies look like s#*@! I have to agree with the early spring. I check my lilies everyday and kill at least a few. I’m also thinking about using Neem. I have read that it bad for honeybees. I found out that there is a safer Neem, called BioNeem. You might what to try that. I don’t like to use insecticides either but there are safer and friendlier insecticides on the market.
I’m from Upstate New York. 50 miles away from Montreal, and 15 miles away from the Vermont State Line.
I live in Alton NH I have had these beetles for 2 years now. Last year they ate all of my lily plants as well as stunting the growth, this year I bought a pesticide from Gardens Alive called Pyola insect spray. It seems to work for at least a few days and then I have to spray again but they don’t seem to be as infested this year as they were last year. I put some microscopic grub killers called nemotodes in the garden also that I got from Gardens Alive, it seems at least to this point to be keeping other insects at bay, but obviously is not working on the lily beetles.
Newburyport MA, May 26. This is the third year that handpicking has been very effective for my dozen lilies. This year I killed 7 beetles between May 4 and May 14 and have seen none since. Killed two large nasty frass-covered larvae yesterday. So far, so good! Now realize I forgot to look for the eggs.
How far are these beetles flying from garden to garden?
If indeed these beetles spend the winter in the soil, would it be effective to scoop off and replace the top inch of lily bed soil in late fall our early spring?
I read at the URI web site that they sometimes like to overwinter at a distance from the lilies, so I wouldn’t bother replacing the soil right around the lilies. I also read that when hand picking, sometimes the little buggers like to drop down onto their backs, camoflaging with the soil (they have brown undersides) so it can be useful to put a sheet of white paper under the plant that you are working on. Good luck!
I found my first 3 LL beetles of the season. Nasty things. I have used Neem oil for treatment, but, I generally pick them off.
5/28/09
I had heard about these things being in Amherst, MA but somehow they seemed to stay on the other side of the Ct River, so I did not worry about what was not eating my plants. When I saw my lily’s last Friday, I knew I needed to go back and re-educate myself.
Since the larvae looked a lot like slugs and my favorite way to get rid of those pests is salt, I tried a water and salt mixture. I poured it over the plant and the larvae started to turn white and drop off the leaves. I did not stick around to see if they recovered and have not had time to thoroughly inspect since ~ too much rain!
I will go back this afternoon and check it out. I wanted to know what was recommended to do battle with these guys. Sounds like neem has some undesirable side effects.
Was just walking by my lilies after several rainy days and saw that the only open one had been partially eaten — and was covered with what lookied like dark brown slime. On closer inspection, it seemed to be a bunch of beetle-type thinigs — but very squishy and slimy. I washed off as much as I could with the hose. I have Neem and other things in my shed — will give them a try.
I have these horrible bugs in Enfield, CT. They drive me crazy. I’m just glad they’re red so I can spot them easily.
Last year I have been warned about these red beetles. I found just a few, picked them and stepped on them. This year it is a different story. I have only a few Asiatic Lilies in my garden. The winered one is the earliest blooming. I saw quite a number of beetles and picked them. With all the picking I did, several times a day I would check, I was surprised to find always new beetles. After and during some rainy days, there were none; but then I discovered the slimy black masses under the green leaves. They were all over. I cut the whole plant down and put it in a thick empty plastic bag (morton salt bag) along with some insect killer dust into my garbage can. The plant had not even yet bloomed. Hopefully that will take care of it. But yesterday, I discovered the same black masses on the lower part of my other Asiatic Lilies. Today, I discovered this blogstyle website and want to thank everybody who talked about Neem. I’ll see today, if I can find some Bio-Neem and also put some of it into my garbage can , just to make sure!! I do live in Central Vermont. Am thankful for more advice. Let’s fight those beetles!!!
By the way, I took a beautiful shot of a parasytic wasp in my garden a few years ago. Never saw one after that again, unfortunately. I know that with there long sting, which is actually stingless, they kill larvas in the ground and these wasps are harmless to humans.
I’m pretty sure that I keep finding red lily beetles in my garden, but they’re on the roses so far. I’m here in Spokane, Washington, which is rather far from New England. I’d like to get some of those parasites for them as well . . .
we have got them in central Maine too, but i have found that diatomaceous earth kills the adults on contact. I apply it with a spray bottle made from a recycled honey dispenser. To kill the disgusting larvae it is necessary to dust each one individually and very thoroly. Here’s hoping we kill them all.
Peggy
The salt trick worked! They have not come back. Diatomaceous earth works much like salt. Salt is cheaper though. I use both on regular slugs and these larvae seem very much the same.
I have found the neem works well, but I do make sure to spray each bug/larvae down individually as I find them, and then I give the whole plant a good dowsing when I’m done. A cheap source for diatomaceous earth: try your local pool supply store. DE is used in pool filters and can be purchased in a very large bag (2 year supply for me) for less than the cost of a small box at a garden center.
Just discovered them today. They’re very pretty but destructive. My lillies look shaggy.
I should have added in the above post that I was grateful to find this website that quickly identified my problem. I am in eastern mass. Thanks, going out now to pick red beetles.
Must have picked at least 100 yesterday. Today I found only ten!
From Northern Vermont: I had just a few Asiatic lilies for more than 15 years with no problem. I bought a few more bulbs from a Dutch supplier 2 years ago and with them came the horrid little red bugs. Now all my plants are sickly – leaves with holes, no flower buds or just a few that wither before opening. I only see a few of the red critters and haven’t had much luck picking them off (they are quick and fall to the ground to hide).
At least it is good to know my day lilies are safe.
Thank you for all the info here.
My friend’s lilies were attacked by these little buggers, and before he knew what was happening, they were all —50+ plants—defoliated. Does anyone know if the plants will come back next year? I am wondering if, without any leaves for photosynthesis, the plants will survive. This happened in July, so perhaps there is time for the bulb to send up some new shoots. I wonder if feeding them, maybe with some plant tone, or something that lilies like (?) would be helpful. It would be a shame to lose all of the plants.
Oops, forgot to say, we are in Northwestern CT. Would appreciate a reply from anyone who has had infestations in years past. Thank you!
since what I have seen in my own garden I agree that what I have is an imported beetle described earlier (2006) I’m not clear on pesticde use in particular but I would rather use natural deterants to control destructive pests. in my area we have instituted a pesticide free by-law and wehave seen the uncomfortable but neccessary effects.although there are more bulb eating pests there are also many more polinators…something that is a concern…butterflies, honeybees and hummingbirds are more abundant where I live…I’ve even seen a few bats! I think that although pretty as they may be, our flower gardens are not as important or (lets be honest) as beautiful as our own indigenous wildlife ,flora and landscape .