By Loobee
Cheshire, United Kingdom
Hi. I have a large old Laburnum tree in my new garden which seems to have a problem. Yellow/red small lumps develop on the surface of the leaves and the leaves develop white, yellow and brown patches. Does anyone know what this may be? Any advice welcome. Many thanks. Louise.
- 13 Nov, 2009
Answers
Oh right, thanks. Seems I know even less than I thought. I thought it was because it has the hanging yellow flowers and the arched pods. Any ideas on what type of tree this may be?
13 Nov, 2009
I could be wrong lets see what the others think first Loobee?
13 Nov, 2009
This looks more like an Acer of some kind, possibly Acer opalus - this has yellow flowers in spring, followed by winged seeds, rather like sycamore seeds. Perhaps you could google it and find a picture to see if it is that species of tree. Its not Laburnum, Drc's right about that.
As for what its got, the small red lumps on the leaves are probably some kind of leaf gall, which may then go on to cause the further discoloration you describe. I shall have to check the pests and diseases book thoroughly! I do see in the picture little white flecks on the upper side of the leaves - were they moveable, as in an insect sitting on the leaf, or a deposit that could be moved, or markings actually in the leaf itself?
13 Nov, 2009
Well the obvious is Acer gall mites, which cause small red pimple like bumps on the leaves - there's no treatment other than removing badly affected leaves, and they don't harm the tree. That wouldn't necessarily cause the other problems you're describing though, particularly not the white patches - which may be aphid infestation or some kind of mildew/fungal problem, depending on whether they were "moveable" or not, as asked in my previous answer.
13 Nov, 2009
Thank you guys. Particularly Bamboo for doing your research. I initially thought the tree was an Acer but my knowledge is extremely limited and the trailing yellow flowers confused me. I have been busy googling Acers but cannot find a picture yet to match the flowers. There are not many pictures unfortunately. The shape of the leaves match and the seeds are very much like sycamore seeds. I have found some pictures of the gall mites and they look extremely like the ones I have and believe your diagnosis may well be right. Regards the white patches, if my memory serves me correctly, they appear to be markings in the leaf. My tree does get a large infestation of winged aphids each year on the underside of the leaves which may be the cause as you suggest. Where do I start? Any ideas. To remove the leaves that have the gall mites would result in me stripping the tree of most of it's leaves. Many thanks.
13 Nov, 2009
I don't know how big the tree is, so hesitate to suggest you spray with an insecticide in case you can't reach it anyway! I wouldn't worry about the Acer gall so much, its whatever else comes that you might be able to treat. It might be best to wait till next year and keep an eye on it, then when you see this "infestation" of insects, post a pic here or decide what they are, and then get the appropriate treatment and spray, if necessary. If the seeds are winged and similar to sycamore (bit like a single prop plane, nobble in the middle, wings either side at an angle) then that confirms it is an Acer. I have a pic here in my tree book, but haven't checked on line, but no matter, at least its confirmed to be an Acer. Be nice to see a pic when its in flower next year too!
13 Nov, 2009
Thanks so much for the advice. The tree is as high as the house. Will take your advice and wait until next year. I will definitely post a pic of it in flower next year. I have grown quite fond of this tree despite the pests attached.
13 Nov, 2009
Aceria macrorhynchus. A mite parasite of sycamore leaf.
Don't know how to treat it .
14 Nov, 2009
Thanks for the info Stjohntogue.
15 Nov, 2009
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