I've an oak tree, not mature, about 12-14" thick at the base of
the trunk. Quite a lot of the leaves are going brown - the upper
surfaces look normal, except for brown patches of course, but
the lower surfaces are covered in patches of "stuff". Imagine
a miniature umbrella, open, without the handle, with the spike
dug into the underneath of the leaf. Now imagine many of these
per leaf, some mature looking browny spots, some new-looking
green ones, of smaller size. The diameter of the larger spots
must be about 1/6" (just over 4mm). These spots, or scales, are
held onto the leaf by the central "spike", and can be levered
off with the point of my pen-knife.

Here's an attempt at ASCII art, may not come out properly unless
you're using a fixed-width font (poss. not even then!):

################################ - leaf
__|__ _|_ _|_ - things
/ \ / \

Mature -- immature
brown green

The umbrella shape is rather exaggerated.


What sort of nasty are these??? Any help much appreciated!

http://images.google.com/images?q=oa...=Google+Search

Regards,
Emrys Davies.




wrote in message
...
I've an oak tree, not mature, about 12-14" thick at the base of
the trunk. Quite a lot of the leaves are going brown - the upper
surfaces look normal, except for brown patches of course, but
the lower surfaces are covered in patches of "stuff". Imagine
a miniature umbrella, open, without the handle, with the spike
dug into the underneath of the leaf. Now imagine many of these
per leaf, some mature looking browny spots, some new-looking
green ones, of smaller size. The diameter of the larger spots
must be about 1/6" (just over 4mm). These spots, or scales, are
held onto the leaf by the central "spike", and can be levered
off with the point of my pen-knife.

Here's an attempt at ASCII art, may not come out properly unless
you're using a fixed-width font (poss. not even then!):

################################ - leaf
__|__ _|_ _|_ - things
/ \ / \

Mature -- immature
brown green

The umbrella shape is rather exaggerated.


What sort of nasty are these??? Any help much appreciated!

Emrys Davies wrote:
wrote in message
...

I've an oak tree, not mature, about 12-14" thick at the base of
the trunk. Quite a lot of the leaves are going brown - the upper
surfaces look normal, except for brown patches of course, but
the lower surfaces are covered in patches of "stuff". Imagine
a miniature umbrella, open, without the handle, with the spike
dug into the underneath of the leaf. Now imagine many of these
per leaf, some mature looking browny spots, some new-looking
green ones, of smaller size. The diameter of the larger spots
must be about 1/6" (just over 4mm). These spots, or scales, are
held onto the leaf by the central "spike", and can be levered
off with the point of my pen-knife.

Here's an attempt at ASCII art, may not come out properly unless
you're using a fixed-width font (poss. not even then!):

################################ - leaf
__|__ _|_ _|_ - things
/ \ / \

Mature -- immature
brown green

The umbrella shape is rather exaggerated.


What sort of nasty are these??? Any help much appreciated!





http://images.google.com/images?q=oa...=Google+Search

Regards,
Emrys Davies.



None of those pictures look anything like what is described though. They
almost all show oak leaf blister which is doesn't seem to be the OPs
problem.

I'm curious to see if anyone can identify this rather bizarre sounding
gremlin.

Thes

Thes wrote:
Emrys Davies wrote:
deepdigger wrote...

I've an oak tree, not mature, about 12-14" thick at the base of
the trunk. Quite a lot of the leaves are going brown - the upper
surfaces look normal, except for brown patches of course, but
the lower surfaces are covered in patches of "stuff". Imagine
a miniature umbrella, open, without the handle, with the spike
dug into the underneath of the leaf. Now imagine many of these
per leaf, some mature looking browny spots, some new-looking
green ones, of smaller size. The diameter of the larger spots
must be about 1/6" (just over 4mm). These spots, or scales, are
held onto the leaf by the central "spike", and can be levered
off with the point of my pen-knife.

Here's an attempt at ASCII art, may not come out properly unless
you're using a fixed-width font (poss. not even then!):

################################ - leaf
__|__ _|_ _|_ - things
/ \ / \

Mature -- immature
brown green

The umbrella shape is rather exaggerated.

What sort of nasty are these??? Any help much appreciated!

http://images.google.com/images?q=oa...=Google+Search

None of those pictures look anything like what is described
though. They almost all show oak leaf blister which is doesn't
seem to be the OPs problem.

I'm curious to see if anyone can identify this rather bizarre
sounding gremlin.

Thank you Emrys, Thes - it isn't oak leaf blister, these
things are like a somewhat concave disc on a little stalk
which attaches to the leaf. Break the stalk and the disc
pops off. They are quite closely-spaced on some leaves,
which are going brown.

On 12 Aug 2004 14:07:31 -0000,
wrote:

Thes wrote:

Thank you Emrys, Thes - it isn't oak leaf blister, these
things are like a somewhat concave disc on a little stalk
which attaches to the leaf. Break the stalk and the disc
pops off. They are quite closely-spaced on some leaves,
which are going brown.

Sounds like some kind of gall - google on that - you'll probably come
up with something.

=================================================

Rod

Weed my email address to reply.
http://website.lineone.net/~rodcraddock/index.html

wrote in message .. .
Imagine
a miniature umbrella, open, without the handle, with the spike
dug into the underneath of the leaf.

What about The smooth spangle gall
http://www.bioimages.org.uk/HTML/P30131.HTM

They are all caused by gall wasps, some almost invisbly small.

Oh I say. Thank you very much. It seems to be the common spangle
gall, with some of Mr. Harvey's smooth spangle gall, which I
mistook for "immature galls". Fascinating stuff, there's some
information at:

http://www.btinternet.com/~arb_excha...d_spangle.html

with a link to the "currant galls" which are part of the life-cycle
of the wasp earlier in the year.

Concise information and well worth a glance!

Thanks again.

wrote:

Oh I say. Thank you very much. It seems to be the common spangle
gall, with some of Mr. Harvey's smooth spangle gall, which I
mistook for "immature galls". Fascinating stuff,

Isn't it. My oak has the common and silk spangles every year, and
occasionally this one:
http://www.bioimages.org.uk/HTML/P45254.HTM

and over half our acorns have Knopper galls
http://www.bioimages.org.uk/HTML/P30118.HTM
http://www.kulak.ac.be/facult/wet/biologie/pb/kulakbiocampus/gallen/pagina's/eik-knoppergal2-Andricus%20quercuscalicis.htm
although they look more like the picture he
http://www.gwydir.demon.co.uk/insects/cynipidae.htm


On that last page is a robin's pin cushion - we have that on a wild rose
this year for the first time I can remember since moving here. I
suspect the 'robin' in question might be robin goodfellow. What do you
think?

On 13 Aug 2004 10:13:28 -0000,
wrote:

Oh I say. Thank you very much. It seems to be the common spangle
gall, with some of Mr. Harvey's smooth spangle gall, which I
mistook for "immature galls". Fascinating stuff,

It's worth adding that these things are practically never seriously
damaging - just interesting - slightly disfiguring at worst


=================================================

Rod

Weed my email address to reply.
http://website.lineone.net/~rodcraddock/index.html