[rich24uk]

I think my poor conference pear tree is ill. Any ideas what this is? Its blossoming like usual but the twigs seem quite brittle.

[Chrysalis]

well, it's not a partridge 

Looks like an infestation of scaly things....  Our fruit trees get 'em, too (as well as the bay tree).  Not sure how to treat.  if it's only a few, I scrape them off with a thumbnail and wash the leaves.  But if it's alot   

Someone more learned than I will probably have a better solution. Good luck with it, C

[mumofstig]

I agree it looks a bit like scale insects see the RHS site
http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=224

and they do come in different colours, I had grey ones last year on my gooseberries.
I used the Bayer control the RHS recommends, about now, but it would be difficult to apply to a tree of any size.

[rich24uk]

Would that also explain why the trunk and branches might be so brittle? It looks like it's infested the enitre tree...

[AdrianH]

Looks like Blister Mite. We have it in our pear tree too. Not much you can do about it apparently. The mites hibernate over winter in the buds an then move out into the leaves during spring and summer, going back into the buds later in the year. One recommendation is to wait till later in the summer and removing all th leaves, this taking the mites away before they migrate back into the buds.