Photo would be helpful - at first I thought it was scale insect, but they're quite difficult to remove without scraping, so probably not.

Sorry Bamboo, I have seen this species several times before on this plant. They are indeed scale insects though a different type to the ones you are referring to Bamboo. They are huge indeed!

You will have to spray with a systemic insecticide such as provado.

Oh interesting - do they have a name, Fractal?

I haven't looked up their scientific name (or common one if they have one). They look like small limpets. We had a large specimen in a tub at work and one year suddenly noticed them. Every primary branch up to second year wood was covered! They scrape off easily enough and contain the adult gravid female surrounded by masses of tiny white eggs. They squash to produce a browny-yellow liquid.

I suspect that they come into this country from the many imports such as southern Europe (Italy for instance). I don't think the Uk has any native species this size. Never seen them on anything else including other types of Robinia either.

They look exactly like these Armoured Scale insects. They are the type that don't produce a pad of "cotton wool" from under one side and remain clamped like limpets at all times through their life.

http://www.wildaboutbritain.co.uk/gallery/files/4/1/5/1scale.jpg

Thanks for that info - hmm, armoured scale insects, another one on the list of pests then.

Thanks Bamboo and Fractal. Was very pleased to discover what the little blighters were. Bamboo answered a query, I think from Brian Lambert, who sent a picture of his Lace Lady with this Armoured Scale on. These are exactly the same little brown 'things' that we have on our Lace Lady branches.
When my husband started to remove them this morning, (with a toothbrush ! no less, as he didn't want to damage the small new shoots :) ), they did produce browny-yellow liquid, but left behind a powdery white mark.
Many thanks for your EXCELLENT advice and have since joined site in case we get any more queries :)

Just as a matter of interest, do they actually do the plant any harm? Do they feed off it?? We have a couple of branches that seem to have died off.
Many thanks....

Indeed they do. The wingless female insect that resides under the "scale" sucks the sap and many of them add up to a big problem to the plant and can certainly cause smaller, weaker branches to die. The white powder is a mixture of tiny eggs and a waxy substance secreted by the insect.

Hi Fractal

I read your reply with interest..
Even though my husband has brushes these little critters off, they have fallen amongst the bark chippings around the base of the tree. Would they survive to cause further problems? He also hosed the tree tonight when they sun had moved off it and it had gone cooler. Also, when we get the insecticide, should we spray the chippings too, to make sure? The reason I ask is, could it be harmful to pets? We have cats and Copper, a long hair teenage delinquent of the cat world, likes to lie under the Lace Lady when it's sunny, during one of his 'quiet' moments. Concerned if any of the three lie on it, in case the insecticide got onto their fur and if they licked it, it could make them sick (?).

Many thanks once again for the invaluable advice. In all the years we have been gardening we have never come across these Armoured Insects before, but as you say,they could have come across from southern Europe...the world is a much smaller place these days...

Hello there, I have just found these on my lace lady after noticing it wasn't happy, is it best to pick them off and spray or spray then pick them off we have two of these at our front door and really don't want to loose one or both, your help is appreciated, thank you.

Wash them off, preferably without damaging any new, soft wood. Seems Janiejoo did it with a soft toothbrush, but a soft cloth (preferably disposable, it'll get yukky) can be used on larger areas.

Hi Bamboo, Fractal & everyone

Thanks for all the comments regarding the scale insects. Just a tip... we found that they also like flowering currents too, also our kiwi plant & shrimp plant were attacked! So please watch out for them! We seem to have them controlled (fingers crossed!) You can buy a spray Provado Ultimate Bug killer which is brilliant but we are still vigilant!!
( Had trouble with the old PC last year, decided to 'pickle' itself, so lost a lot of 'stuff'... Modern techno!)

Try a cotton bud dipped in meths spirit and dab each insect,they usually succumb, it's time consuming but I have found it effective.

Yes,meths is good - I lightly moisten a disposable cloth with it and rub it over the trunk and branches to get them off on Acer particularly, but its no use for scale on leaves, the meths isn't good for those.

We find that if we look on the robinia, or other plants which have been attacked previously, just before leaves appear in the spring ( starting to bud), we can usually see these scale insects more easily if they have returned. However, we usually spray just in anyway!

I don't wanna be a party pooper, Janiejoo, but provado is one of the pesticides that seriously affect bees and other pollinators in the environment - I use it like an AK47 - only when its absolutely essential and sparingly.

Thanks for that info regarding Provado. Although it may sound as if we use it willy nilly we don't. We try not to use any type of spray etc, only when really necessary, and thankfully, as our Robinia is WELL away any flowers, we have ONLY used it when absolutely necessary. We've not actually used it since after my first post when I was trying to find out what these scale insects were. We are just extra vigilant when spring is just around the corner..... Thanks once again though, as we like to encourage birds, bees and any other insects etc. We even had a dragonfly resting on our shrimp bush the day before last, for about a day. We're not that close to water, but then again, the amount of rain we've been having this year it's probably confused the poor little blighter! :)

Now I'm wondering what a shrimp bush is, lol...

Salix Hakuro Nishiki!! It has beautiful varigated foliage, tinged ( tipped) with pink. It looks a bit like little shrimps nestling in the foliage :) It's very pretty, and ours is now about 5ft.

Ah, yes I know that plant, but never heard it called Shrimp bush before!

Ha! Ha! Probably just a little one of our little 'pet' names for it!! :)