It would unusual to see eriopyiid gall formation on branches - leaves and
petioles usually. If the original post is correct, my impression would be
more like cynipid gall wasps or and Agrobacterium-like infection in the
woody tissue.

I am admittedly weak on the local patho-flora and fauna of Canada however!

Mike
--
Mike LaMana, MS
Heartwood Consulting Services, LLC
Toms River, NJ
www.HeartwoodConsulting.net


"Sed5555" wrote in message
...
I have a fully grown, 25 year old ash tree. A few years ago some crunchy,
crab-apple type growths appeared on some of the branches.

Sounds like dried eriophyid mite galls. These microscopic mites commonly
cause
deformed galls on ash trees that are originally green but dry to a crumbly
dark
brown. Although unsightly, they rarely affect the health of the tree. For
more
information see:
http://www.colostate.edu/Depts/CoopE...sts/emite1.htm
and
http://www.colostate.edu/Depts/CoopE...ests/galls.htm
sed5555