Tiny limpit like parasite attacking Bay, Acers and Magnolia

[JennT]

Hi there, my shrubs seem to be suffering from some sort of parasite that looks like a tiny limpit, with fibrous material under the 'shell' when you disturb it. Does anybody know i)what it is and ii)is it harmful?

Thank you in advance

I can't help unfortunately but I will be watching this thread with interest as I have an acer which is suffering with the same problem :(

Does it look like \link{http://www.radleyvillage.org.uk/ourvillage/natural_history/images/redspots_IMGP0674.jpg\this} - maple gall mite?

My acer is suffering too, though not in the same way - it was covered in aphids a few weeks ago (and ladybirds - so I just left them to it) and now I've noticed that the trunk has a thick white fungus on it, just like it's gone mouldy.

Mine is suffering in exactly the way you describe. I have a dogwood which also has this stuff on it.
I have no idea what it is - I scraped a load off and it was like gooey marshmallow underneath (to look at obviously I didn't try a bit)
Will have a look now to see if I can find out what it is

Does it sound like this, cos I think that's what mine has got:

Scale: Many scale species including Pulvinaria acericola, Pulvinaria innumerabilis and Melanaspis tenebricosa are pests of maples. Scales are unusual insects in appearance. They are small and immobile, with no visible legs. Scales vary in appearance depending on age, sex and species. Some are flat and appear like scales stuck to a plant, while others appear like white cottony masses. They feed on sap by piercing the leaf, stem or branch with their mouthparts and sucking. Their feeding can weaken or kill branches. Heavily infested trees are stunted with small flowers and leaves. Leaves may yellow and drop early. Like aphids, they also excrete honeydew. The growth of the sooty mold fungus results in leaves that are dark. Adult scales are relatively protected from insecticides by their waxy covering. Their immature forms, called crawlers, are susceptible, however.

Have a look at \link{http://s142412519.onlinehome.us/uw/pdfs/A3123.PDF\Cottony Maple Scale}

WWB it is def not maple gall mite but thanks.

MJ think you've found it! It does look like marshmallow MM. So according to that article wash it off, and it isn't too harmful to the plant.

Thanks very much everybody.