Apparently it's becoming a real nuisance - my mum saved an article about it from some national newspaper recently (bless 'er!) From what I gather you'll need to be pretty vigilant at getting rid of them - I'd probably carry on religiously picking them off and giving them the boot/ground treatment.. Just don't let them spread up north! ;)

Melanie

Is leaf stripping the symptom? i've been trying, with little success, to find descriptions of the damage caused by the beetle. My Rosemary bushes have nearly all been badly affected by die-back over winter. They range two to three years old, with no history of ill health. Not seen any beetles yet, but only just heard of them.

Yes, they strip the leaves but some of the stripped parts eventually go black and die off too. Try looking down the stalk at a green area just past the damage. If you find a grub with grey vertical stripes, that's the young of the rosemary beetle. You might also want to try going out there at night with a PIR light on in the garden, or shine a torch on the bushes at that time, as I noticed the shiny metallic shells of the beetles are easier to spot by artificial light at night.

PS when I said 'vertical stripes' I meant along the length of the grub - it was probably not a good description. Sadly it got to the point that I decided to throw out one of my bushes - it had just got so unsightly and sick looking with all new growth gone. I was trying to be vigilant but I think I spotted the initial damage too late because it happened in winter when I wasn't out in the garden as much.

Thanks for this post, Lori - I had not heard of this pest, although I am in the most affected area according to the article. Will watch out for the little buggers...

Making the link 'clickable' for anyone else who is interested.

Here is a link that might be useful: Rosemary beetle info

We have this rosemary beetle in Lincoln (UK) I have picked off about 20.

From the link:

Rosemary beetle can be controlled either with insecticides or hand picking of the adults and larvae. There are no recommended insecticides that can be used on rosemary if they are to be used for culinary purposes.

If pesticides are used then these are best applied in late summer to early autumn or in the spring, when the beetles and larvae are active on the plants. Suitable insecticides that can be used include bifenthrin or imidacloprid.

Insecticides should not be used while plants are in flower because of the danger to bees.

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I imagine that it would be OK to eradicate the pest with a uitable pesticide and not use the herb for a year or two? I wouldn't fanct eating it though even years after.

It seems to have been the mating season a few weeks ago. Then I was finding about 10 a day. It also turns up on my lavender and apparently you may also find them on other members of the Lamiaceae family. Because I was being vigilant I've found only one a day more recently. I find it easiest to flick them off into a plant saucer then tap it out onto the ground and squash them. I've also heard you can put something like an old sheet underneath the bush and shake the bush. But I find that also shakes out loads of spiders which are currently hanging out in the bush (I'm hoping they are getting a taste for rosemary beetles!)

Since South London, where I live, apparently has more rosemary beetles than anywhere else in the country, I don't see much point in using pesticide - they'll be sure to come back from someone else's garden so I'll have to keep on using it. The main reason I'm growing rosemary is as a culinary herb.

I have abundant rosemary beetle on my Rosemary in a large pot on the roof. The plant has been almost destroyed. Surely these beetles have a natural predator-everything else does. Does anyone who has rosemary in the ground (as opposed to being in a tub) have the problem. I'm wondering if the large predatory ground beetles might eat them. I know I have only centipedes and spiders in my arsenal but I'm going to collect some staphylinid and caribidae ground beetles in the local park. Just sink a clean jam jar in the soil up to its rim and the beetles fall in overnight. I'll give them a try although i don't think these ground beetles climb much. Will report back.

No doubt they do have natural predators, just not in this country. The beetles themselves are barely hard enough to survive here, one real cold winter will hopefully kill off the whole lot. I certainly don't want them to make it up north!

It's worth trying anything, I suppose, but my rosemary and lavender are both in the ground. My vigilance with the rosemary has paid off, and it's looking healthy - unfortunately my lavender is in the front garden and I haven't felt much like doing the 'knock them into a saucer then stamp on them' trick on a regular basis out there so they've had the chance to do more damage. Consequently the lavender's in such a bad way I'm now thinking of removing it. I suppose I can comfort myself with the fact it was getting old and had really outgrown its space.

I live in West London and my rosemary was decimated last yesr by this pest, this morning (07/06/11) I have collected 50 from my rosemary and lavendar plants. They can be collected all day but seem never ending.