Norfolk Pine decline

T

treekiwi

Location
Auckland,New Zealand
hey guys :),
Here in Auckland we seem to have a case of Virus infection in the tops of Norfolk Pines... The apical growth firstly faciates into a coral-like form and then begins to decline slowing down the stem but never really reaches much further than the top 1/3 of the tree... It is very bizare. The top then dies out to this point and takes a few months to re-shoot. Have any of you come across anything like this? What insect could be resposible? /forum/images/graemlins/confused.gif
treekiwi
 
You can check out this bugger Sirex noctillo, Awasp that seems to be killing off pines. I posted Conifer wasp about him, but the arrtilce exspired. That is all I can do on that I am not to good on the bugs, but am learning.
 
Ahhh, we covered this one, let me check my notes ....
.... possibly cypress bark beetle or something similar, a borer style of pest.

I dont think it's the Sirex wood wasp as that would kill the whole tree.

Do you think the trees are slightly stressed, perhaps less rain fall than usual or being Norfolks ... frost effected?

My deductions are that the weakest point is being attacked, and that's the part furthest from the roots (the tip). It could well be that lower down there's sufficient resin to flood out the little buggers. Also the larger stems may have a portion of the cambium uneffected and survive.

Pics would be good. You'll need to cut off effected sections and burn them, disect the sections and look for galleries. The Cypress bark beetle only has a 1.5mm to 2.0mm hole so you have to look closely.

Usually die back on the top of a tree indicates root damage and drought stress, could be a combo of that plus frost and the beetles have moved in.
 
Hey Ekka,
It is all rather puzzling to be honest, there is no signs of root stress and it effects alot of tress in parks and urban gardens alike. They are all in Auckland and we rarely get a frost here especially that would effect the foliage of the Norfolk. Fasication seems to occur first followed by the dieback to 1/3 of the upper crown where it seems to stop... Very strange, it fasciated in a claw or coral like structure and then dies back which to me seem to be classic signs of a virus, willl have to look out for the beetle you suggest :)
treekiwi
 
Here's some links, I have no idea, suggest getting city council to inverstigate.

Our govt released a bug Lanatana bug to try and kill off lantana in the bush etc, this is only a few years ago. well it decimated the fiddlewood trees.

Maybe something has been released, maybe a bug is carrying something it never used to, maybe acid rain or nuclear fallout! /forum/images/graemlins/crazy.gif

There would be a reason but man it could be anything. For example, they are and have done tons of aerial baiting and spraying for fire ants here to eradicate them ... who knows, maybe it could be something like that, could have even happened years ago and is just now affecting the trees.

Very interesting

http://en.wikipedia.org/wiki/Fasciation

http://www.rhs.org.uk/advice/profiles0700/fasciation.asp

http://www.plantanswers.com/abnormal_arizona_ash.htm
 
[ QUOTE ]


Our govt released a bug Lanatana bug to try and kill off lantana in the bush etc, this is only a few years ago. well it decimated the fiddlewood trees.


[/ QUOTE ]


Ha, no great loss there. /forum/images/graemlins/crazy.gif
 
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