unknown metallic beetle

jrichemont · #1 (**permalink**) 19-06-2007, 09:56 AM

Unknown by me anyway! Hi all...

I found this attractive beetle last weekend living on the stem of my sage bush in central London. I would welcome any help in identifying it!

Photo on Flickr:

beetle on Flickr - Photo Sharing!

Many thanks;

Jeremy

Paul mabbott · #2 (**permalink**) 19-06-2007, 09:59 AM

Yes, very attractive but a potential disaster for your herbs. This is Chrysolina americana - the rosemary beetle although it will feed on other labiate herbs such as sage (as you've noticed), thyme and lavender.

jrichemont · #3 (**permalink**) 19-06-2007, 10:15 AM

Thanks so much for the ident, Paul. I will now check my rosemary bush too! I did think they might be bad news - there were about 20-30 of them in total - and trimmed all sage stems they were on.

Beetles do seem to like my roof; I've had a running battle with vine weevils since moving there (I use nematodes) and a few years where the lillies were overrun with bright red Lilioceris lilii. I am not winning against otiorhynchus sulcatus I fear.

Cheers;

Jeremy

Paul mabbott · #4 (**permalink**) 19-06-2007, 10:35 AM

I'm surprised you haven't given up gardening! Yes, central London is a haven for many aliens because of the heat island effect.
As you'll know, from the lily beetle, it's the larvae that do most of the damage so it's important to seek out the eggs and the larvae at as early a stage as possible ...
Good luck, Paul
PS: don't think about growing asparagus!

Quote:

Originally Posted by jrichemont

Thanks so much for the ident, Paul. I will now check my rosemary bush too! I did think they might be bad news - there were about 20-30 of them in total - and trimmed all sage stems they were on.

Beetles do seem to like my roof; I've had a running battle with vine weevils since moving there (I use nematodes) and a few years where the lillies were overrun with bright red Lilioceris lilii. I am not winning against otiorhynchus sulcatus I fear.

Cheers;

Jeremy

jay2 · #5 (**permalink**) 19-06-2007, 07:31 PM

I got very excited when I saw this!
I did a lot of research a couple of years ago trying to identify these when I found some in my Wimbledon garden. I didn't know about this forum then, but I managed to contact Paul and he helped me. Aren't they gorgeous looking! But yes unfortunately, they will do for your rosemary eventually. I had a huge DEAD rosemary bush, I still have a small sickly one. but I can't bear to destroy these beetles!

elleme · #6 (**permalink**) 19-06-2007, 10:07 PM

After having to take out one mature rosemary bush and a mature lavender which were decimated last year, I'll quite readily kill them. I flick them into a saucer, drop them on the garden path then stamp on them. After doing this a lot last year, I've not had so many - but I'm keeping watch out for them. As for lily beetles, my lilies have virtually had it so I obviously haven't managed to keep on top of those. Don't think I usually harbour such murderous urges towards beetles, but after 2 plants got past the point of no return I'd rather do something about them than not be able to grow any rosemary.

jrichemont · #7 (**permalink**) 20-06-2007, 10:02 AM

Well, I have to admit to cheerfully stamping on vine weevils - they're not even pretty - but I throw the rosemary beetles over the edge now (My garden is on a roof terrace) on the basis that they will be too knackered after climbing back up to eat. I don't think I could bear to stamp on them though.

Strangely I have rosemary as well and they don't seem interested. They just like the sage bush. I found two more on there today. As for the lilly beetles, after that one year where my poor lillies were red with them I haven't seen them since (touch wood).

The vine weevils seem the worst of the lot to me; they have so many traits designed to be annoying: they drop off the plant at the slightest vibration and can't be found in the pot; invisible underground grubs eat your roots, the adults eat any leaves that manage to grow despite this!

Paul mabbott · #8 (**permalink**) 20-06-2007, 10:15 AM

The spread and behaviour of Lily and Rosemary beetles (sorry, not interested in vine weevils

) is being studied by Andrew Salisbury at RHS and, locally, be me in London and Essex. We'd appreciate any observations (when first seen, numbers, location [need a grid reference or post code] and, especially, feeding behaviour) which can be mailed to me, to RHS or on the EFC site:
Species surveys

Could be useful for gardening advice in the future!

Laurence Clemons · #9 (**permalink**) 20-06-2007, 10:43 AM

Can I just say that my garden in north Kent is almost entirely planted with Rosemary, Lavender and Thyme species yet I have not had one Rosemary Beetle. However a single asparagus plant always has a colony of Asparagus beetle.

Paul mabbott · #10 (**permalink**) 20-06-2007, 10:59 AM

Quote:

Originally Posted by Laurence Clemons

Can I just say that my garden in north Kent is almost entirely planted with Rosemary, Lavender and Thyme species yet I have not had one Rosemary Beetle. However a single asparagus plant always has a colony of Asparagus beetle.

Must be the bracing estuarine air - there have hardly been any records from south Essex either!