Right now I hand pick/allow the adults to drop into soapy water. Do you grow quite a few lilies?

This thread discusses many methods, it appears hand picking, Neem Oil, and Sevin mentioned are the more effective methods. I’ll be trying talc/baby powder this year:

https://www.gardenweb.com/discussions/1780575/lily-beetles?n=110

This grower suggests a garlic spray:

http://homes-n-gardens.com/red-lily-beetle-organic-homemade-insecticide.html

Theres a parasitic wasp which is being tested out as of last year, the link is in the other recent lily thread in this forum.

I have about 100. My infestation is massive. I am hoping Canada would have the parasitic wasps for sale this year. Hand picking helps but is very time consuming given the number of beetles I have. I will try Need Oil, Seven and the baby powder. Thanks Prairie_northrose.

Unfortunately Sevin might soon no longer be available for domestic use in Canada as it contains the pesticide carbaryl.

I came across this very detailed study/thesis on the lily beetle -

https://spiral.imperial.ac.uk/bitstream/10044/1/1311/2/Salisbury-A-2008-PhD-Thesis.pdf 

This is also available through Imperial College London at https://spiral.imperial.ac.uk/handle/10044/1/1311  

Three major points I interpreted from the study if I've read things correctly:

1. 1. Confirmation the beetles don't like the species L.regale as much as some other varieties.
2. 2. Non-dormant beetles find lilies by scent.
3. 3. The beetles tend to move away from the smell of Jasmine (cis-jasmone):

"At the concentration of compounds tested, one chemical (cis-jasmone) gave a significant response, where female beetles moved into the airstream emanating from the hexane (clean air) control in preference to this compound." (p.118)

"cis-Jasmone is considered a herbivore-induced plant volatile that repels insect attack and has an indirect defensive effect by attracting predatory and parasitic insects that prey on the herbivores (Bruce et al. 2003). Thus it is possible that movement away from an odour stream containing this chemical is beneficial to L. lilii and this may be the first record of a behavioural response to this compound in the Chrysomelidae." (p.124)

After reading this, I'm going to give spraying with diluted Jasmine oil a try this year.

I wonder if this is why some report Neem oil, baby powder, and garlic spray as being effective - perhaps it is the smell which masks the lilies? I keep a close eye on my lilies and kill every beetle I see in my yard, and the larvae never have a chance to make it to adulthood on my lilies. I find it unlikely they are overwintering for me, it appears they are flying in from somewhere else in the neighborhood, perhaps drawn in by scent.

I'll try the garlic spray this year as well.

I came across an article about Sevin not being available anymore as well. I think I will try the Jasmine oil too. It smells nice to us and deters the beetles (hopefully).

Thanks for the info.

Link got broken above, the name of the study is "Impact, host range and chemical ecology of the lily beetle, Lilioceris lilii"

The file appears to have moved to https://spiral.imperial.ac.uk/handle/10044/1/1311

And direct download is at https://spiral.imperial.ac.uk/bitstream/10044/1/1311/2/Salisbury-A-2008-PhD-Thesis.pdf

Abstract: "The lily beetle (Lilioceris lilii, Coleoptera: Chrysomelidae) has a univoltine life cycle and a limited host range (Lilium, Fritillaria and Cardiocrinum). A survey of 237 professional growers indicates that L. lilii is a problem for many in the UK lily industry. A three-year field trial using six different Lilium indicated that the species Lilium regale is more resistant to L. lilii than the hybrids L. ‘Tiber’, L. ‘Brindisi’, L. ‘Conca d’Or’, L. ‘Eliganzer’ and L. ‘Golden Joy’. Phenology observations between the trial and an established population of the beetle have provided base-line data to which further observations can be compared. Future host susceptibility trials should use a standard lily such as L. regale against which others can be compared. Behavioural bioassays using a linear-track olfactometer demonstrated that the responses of L. lilii to hosts and conspecifics are at least in part odour-mediated. Significantly more diapaused females moved into airstreams containing the odour of intact hosts over clean air, to that of hosts and beetles combined over that of undamaged or manually-damaged plants, and into airstreams from intact plants over larval-infested plants. Pre-diapause males moved into the airstreams of intact hosts in preference to L. lilii-infested plants. Using air entrainment, gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GC-MS), headspace volatiles from beetleinfested host plants have been collected and identified. From these compounds, methyl salicylate, nonanal, cis-jasmone, linalool, 6-methyl-5-hepten-2-one and β-pinene elicited electrophysiological responses from L. lilii using electroantennography (EAG) and coupled GC-EAG. Bioassays indicate that diapaused female beetles move into the airstream of clean air in preference to cis-jasmone. Investigations from all areas of the project have progressed our understanding of the ecology of L. lilii but further studies are needed before more effective control strategies can be developed."

I just love the regale lily, but find that it is nearly impossible to find, at least in white. How ironic that this is the type less affected by the lily beetles and yet it is hard to find.
Do watch out for the eggs under neath the leaves and in the crotch of the stem and leaf. For years I didn't see these. The eggs are a sort of orangy yellow and in groups. Turn over every leaf. But...you may never see them because as the eggs begin to mature the mother uses a creative technique and poops on her babies so that they may be camouflaged. The goobs look so disgusting birds and humans don't want to touch them. You have to give these mothers credit for the steps she goes to to save her babies.
Regarding overwintering, I have seen adults emerging from the ground in the few inches around a lily where the snow has melted before the majority of the snow has melted, so keep your eyes pealed from early in the season on.

It’s definitely beetle season here, I’ve been catching beetles once the lilies started emerging. First beetles were caught around May 3 this year.

I used a product called seven.

It kills everything though even earth worms but works well and keeps them gone for a while

I haven’t seen them yet here in Peace River, but I suppose it’s just a matter of time. I eat all my lily flowers, so I guess it’ll be hand picking for me!

We had lots of beetles show up in May as the lilies were emerging, and now I haven’t noticed any in the last week. I did catch some good sized larvae last week - I had missed the eggs. Disgusting bugs!

In the past I notice the adult beetles seems to take a break and then come back later in the season.

I still haven't seen any at our place. I do live an hour away from the nearest city though (I'm not sure if that makes a difference? No close neighbors?) and I've really slowed down on buying lily bulbs because I'm afraid of bringing them in on the bulbs, since I've heard they can be imported that way.

There's a large scale lily grower very nearby to my acreage and last year the fella had spent many a hour ridding his plants of the pests. I had only four adult beetles show themselves last year and a mere one thus far this season.

I pulled out any plant that is host to that f#$%^&* beetle and its feces covered larva. I had years of pleasure with those plants till it became a twice a day, disgusting chore in order to get 2 weeks of flowers. I'm done. There's a whole lot of trouble-free plants out there. Been gardening 50 years. I'm done with lily beetles!

Strangely I have had no infestations this year. I'm sure they'll show up en masse soon.

Well...apparently they came from the east, here we've seen them for 2 years now, wondering when did they arrive in Alberta?

Konrad, looks like the beetles arrived in Alberta in 2007, https://plantlilies.com/lily-culture/pests/lily-beetle-alert-alberta.html

Definitely larvae season now, I haven’t seen any adults In the last week or two, but I have killed off some newly hatched larvae. It’s more manageable to get them when they’re small.

I saw and killed my first red lily beetle in my garden last summer. They arrived early this Spring...killed the two beetles I saw then and a few larva but haven't seen any more signs of damage since. Funny, they were in an asiatic lily last summer and this year they liked the martagons.

I have had only a few this year so far, much much less than in years gone by. Maybe the cold winter did a number on the red b'tards!

I've had them appear the instant the lilies start coming out of the ground. Like literally they are eating them as the vegetation appears.