By Katharine99
United Kingdom 
We have planted an Acer Palmatum in our garden, which is doing quite well, except we have just noticed that the bark is coming off at the bottom of the tree and is currently covered with wood lice. We know the wood lice will not harm the tree but are wondering if the tree is weak or diseased.
Also sometime in early Spring, we noticed some sticky white clumps on the trunk , which could have either been insects, or a type of mildew.
On plant
Oh, I didn't realise that my original photo was replaced with the other photos.
14 Aug, 2011
Answers
Thank you, I have now updated some more photos and some more information about our Acer.
Thanking you for your time.
14 Aug, 2011
We had the same on one of ours, Katherine. it sounds like scale insect on your tree. See of you can see the little oval, brownish shells of the insect, and the fluffy stuff will be the protective cover for the eggs. You need to get rid of them as soon as you can, because scale insects suck the sap from the tree and weaken it. When we had it on ours, I rubbed off as much as I could and then sprayed with the hose to clean off anything left. If you do this a couple of times it should clear the scales. You can also spray with an insecticide which says it kills scale, but I should try the rubbing and water spraying first, as the insecticide could kill other, good insects. Hope you have success. Annie
14 Aug, 2011
I note you've removed the photo that showed the damage to the bottom of the trunk. I wonder if this could have been caused by over enthusiastic digging or strimming?
15 Aug, 2011
Thank you for the useful information. I hope that we can save our tree and will try to clean off all insects now.
Thanks again,
Katharine
15 Aug, 2011
Hi Katherine and welcome to GoY. That looks like some serious damage to the trunk, could you put up an additional photo of the whole tree, you can add it by editing your question.
14 Aug, 2011