tar spot perhaps?

diggleken · #1 (**permalink**) 01-06-2009, 08:22 PM

Hello everyone,
is this an early stage of sycamore tar spot?

Or what? Quite pretty though!
Cheers
Ken

poschiavanus · #2 (**permalink**) 01-06-2009, 08:52 PM

Nope, its a mite gall, probably Aceria cephaloneus (assuming the red bobbles are under 3mm tall).

I'm not sure if Tar Spot manifests itself this early, but it's certainly visible by late June. In the early stages it is pale and confusingly like another mite gall. I may look and see if I have any photos from last year.

CapAndBracket · #3 (**permalink**) 01-06-2009, 10:48 PM

Good post ken and posch is your man on these, there are some real pretty
ones on lime to look out for.
Interesting you mention tar spot, does anyone one know if tar spot appears
on the leaves where these galls appear.
From what papers i have read about galls it seems some (maybe all) do have
a fungus inside which the larvae may feed on so the plant/insect/fungi
relationship seems something in the unkown. (which certainly makes it interesting).
It seems somehow the insect alters the plant DNA so it produces these
growths, (quite how it may do that is a book in itself).

Cheers J.P.

NickCantle · #4 (**permalink**) 01-06-2009, 11:02 PM

Posch is certainly your man here! I tell you what, I've never heard so much about galls in a 100m walk- with various specimens on show too! Good old Clumber! Nature is so diverse, and every part needs an expert. That's the Poschmeister's Niche

You're at Clumber this year Jerry?

diggleken · #5 (**permalink**) 02-06-2009, 08:49 AM

Quote:

Originally Posted by CapAndBracket

Good post ken and posch is your man on these, there are some real pretty
ones on lime to look out for.
Interesting you mention tar spot, does anyone one know if tar spot appears
on the leaves where these galls appear.
From what papers i have read about galls it seems some (maybe all) do have
a fungus inside which the larvae may feed on so the plant/insect/fungi
relationship seems something in the unkown. (which certainly makes it interesting).
It seems somehow the insect alters the plant DNA so it produces these
growths, (quite how it may do that is a book in itself).

Cheers J.P.

yes, interesting JP - the galls were certainly causing a discolouration when more mature/bigger,which is why I wondered about it being tarspot, in my ignorance of cycles/development!
And of course thanks a lot guys for ID, to all , but Posch partic!

Cheers
Ken

CapAndBracket · #6 (**permalink**) 03-06-2009, 02:33 PM

Here are the galls on lime, a new tree i happened to pass today.

I hadn't seen these before, it looks like the gall has formed at stem end so there
has been little leaf develpment. (does it happen on sycamore!).

Cheers J.P.

poschiavanus · #7 (**permalink**) 03-06-2009, 03:02 PM

Still can't find my pictures of early Tar Spot, so better post anyway. JP you have two galls on the Lime: the first is a nail gall, like the Sycamore one, caused by mites, the other one is a gall-midge Contarinia tiliarum. Just starting to see these myself: they're very obvious on the flower peduncle. There are several kinds of nail galls on Lime, which I'm still trying to work through myself: the commonest has a pointed tip and is over 8mm long - Eriophyes tiliae.

Nick, I hope to get to Clumber & then I can bore you even more with galls - particularly as at the current rate my fungal knowledge is not improving much.

Must dash I've got to get some galls in the post!

Posch

NickCantle · #8 (**permalink**) 03-06-2009, 04:28 PM

Quote:

Originally Posted by poschiavanus

Nick, I hope to get to Clumber & then I can bore you even more with galls - particularly as at the current rate my fungal knowledge is not improving much.

Mutually beneficial conversation rules

CapAndBracket · #9 (**permalink**) 03-06-2009, 08:23 PM

Hope FJ organises a black board for diagrams, this is going to be so interesting.

Cheers J.P.

Chris Yeates · #10 (**permalink**) 03-06-2009, 11:56 PM

we really need a cross-disciplinary forum . . . . I haven't spent enough time on the insects one to know whether such exists (if I'm wrong let me know!

)

but 'galls' can be formed by insects, mites, fungi and mycoplasma-like organisms (and indeed by mechanical damage, or what? - I mean to say what caused this fasciation on Matricaria discoidea - pineappleweed? seen last weekend . . . . spray damage? - no evidence on surrounding plants . . . nematodes? . . . . MLO's?)

naturalists looking at one field of study soon come across others (that was the intention of the fungal plant parasites thread) botanists and mycologists will find galls and (something not yet mentioned) leaf-miners . . . . these are all worthy of study, but how best to bring all this together?

help, Nick!

cheers

Chris