This critter: good or bad?

[NotAnEMERGENCY]

I've found a few of these on my container plants (Cistus, Armeria, possibly others too).

They are tiny white hairy/spiky things about 3mm long and 2mm wide. I think they look a bit like two snowflakes stuck together. I haven't been able to find any info on Google.

What are they? And are they harmful to my plants?

They look most like a mealy bug. They're sap-suckers. If you've only got a few, the easiest is to squash them. They can be difficult to attack with insecticides because they have a waxy skin which makes it difficult for the insecticide to penetrate; and in any case I prefer not to use an insecticide because none of them are specific, they all to a greater or lesser extent will kill beneficial insects as well. There is a biological control available, but I've not managed to get it to work - it needs consistently warm temperatures, and has a habit of flying away in search of better concentrations of mealy bug.

That's most definitely a mealy bug. They are impervious to insecticide. You need to wipe the plants with rubbing alcohol to kill them and the eggs. Then keep doing it until they stop coming back. Don't let them take hold, they are a nightmare to get rid of.

Thanks for the responses!

When I saw Mere's post, I looked up mealy bugs on the internet and decided I wasn't convinced that's what I had. The photos on Google didn't quite look the same and all info on mealy bugs seemed to indicate that they live in clusters, whereas I have only ever seen individual ones.

But if runoutof agrees with Mere, that's not good news! I'd better see what I can do before they get the upper hand!