Red Lily Beetles..

Just as I was about to get annoyed with Hornbeam about monocultures and such like I see his excellent advice about grease lines and wwater traps. Good one Mr H. Will try it next year.

Re Lily b*stards/beetles, they arrived in a batch of bulbs from grotty Nine Elms market. Dutch lilies in the late 1980s, supposedly free of the things.Nows they are well established. I have yet to see any bird eat one, and I suspect the colouration gives the reason why; poisonous though I have no evidence to support that. But they aren't native, so any bird looking on would be wise to eat elsewhere, and would be indeed sick to eat the grubs...

Hornbeam, as a man of diverse horticultural tastes, are you really suggesting that you have few or no Liliaceae in your lovely plot?

 

Vine weevils and flat worms were unheard of to a lot of us years ago, now they are slowly marching on destroying everything in sight
So much for tree and plant quarantine

Kandy

 

I have always picked these red beetles off by hand but when they see you coming they just let themselves drop, so you have to be quick. Some always manage to escape and then later on in the year the disgusting lavae covered in their poohs arrive on the scene. We don't spray as we have a large pond with all the critters that live in it. Oh, we have day lilies almost next to the red-beetles favourite lilies and have never had a problem with them. In the meantime I am just about off of lilies as beautiful as they are.

 

Not sure what has annoyed you about "mono-cultures" jazid. If you have a field of cabbages, potatoes, corn or anything else - it is a mono culture and will attract the insects that feed on it. That is why farmers have to spray so much. As they also spray to kill weeds, the soil becomes poisoned too and so natural pest destroyers like nematodes and beetles cannoit live there. There are very many more earthworms (which are essential for a healthy fertile soil)in a multi-culture garden than in a mono-culture wheat field.

Don't understand your question about lilies in my garden. My post indicated that I grow lilies in pots because of wet winter soil. Other than that I grow lots of snakes-head fritillaries in beds and in my damp wild flower meadow.

 

I guess it was the perceived implication that my gardens represent mono-cultures. I have already discounted that as precious of me.

With regard to the lilies, my point was that the beetles prefer lilies and crown imperials from which they can be removed, but they also breed in 'second best' foodstuffs like day lilies etc which they damage far less, so they are nigh on impossible to eradicate from a garden without overkill spraying. I can't bring myself to spray a tranch of almost perfect convallaria, so as a result the beetles breed and my lilies cop it the next year. I spray them because the beetles have no useful function in the garden, and the lilies look awful if they are not dealt with.

These flipping beetles have been running on two life cycles a year in my gardens for the last couple of years. It used to be one. There's evolution and global warming at work for you.

 

The best thing to do is to have a blitz and try to disrupt the life cycle. Don't forget the pupae and adult beetles live just under the soil- don't just remove adult beetles. In Autumn and Spring sift through the soil underneath the lilies and squash adults and pupae, or completely remove the top 1-2" of soil. and replace it. Physically remove the larvae and eggs from the underside of leaves by wiping them. I know the larvae are disgusting but not so bad when they are very small.
If you can drastically reduce the numbers in one generation then handpicking becomes feasible. Unfortunately the beetle isn't native to UK so there are few predators, but it is not well established in all parts of the UK yet. I imported mine through ignorance!
As has been said Provado does work, but it is a bit like using explosives to crack nuts. Break the lifecycle with a bit of intensive work and then the problem becomes manageable. My experience is that they don't eat hemerocallis and much prefer big lilies to fritillaria etc.
I think the colouration is a warning sign to birds, whether or not the beetles are actually poisonous.

 

I would guess that the adults are not likely to be much eaten because or their bold colour and because they are recent arrivals. However, the fact that the grubs see fit to disguise themselves with their poo suggests that they are vulnerable meals for some predators. New arrivals are always a problem - be they plant, insect or squirrel. Nature will find the right balance eventually, but she takes her time.

I make no "implications" about your garden, jazid. I have no knowledge of it, but cannot believe that it is a monoculture unless its all lawn or all lilies :confused:

 

For me - when thanks to some new orientals I got lily beetle and they stripped all my lilies - a pair of secateurs and a daily check got rid of them. Plus removal of any grubs seen. The secateurs - I found that if I tried to pick them off, they just dropped to the undergrowth usually belly up and I couldn't see them. Secateurs instead of fingers worked a treat - so did shaking the stem over a concrete path and stepping on them.

Seems to have worked after two years - but I will be vigilant again next year.