Elm Trees Under Attack!

Helloooo again

Under our big (maybe peppermint / E. obliqua mystery hybrid) gum tree, we cleared out some undergrowth and potato vines to discover 2 young elm trees, which we assume haven't been planted on purpose as they're completely shaded by the gum and one is growing through the chicken wire fence. The poor things are really suffering.

Both are infested with elm leaf beatle, but one also has some weird growths on some of it's branches, which appear to be starting to spread down the trunk on that side.



We're debating whether to try and save them, or from the position that they're in (under the gum) and the condition of their health, should we just take them out?

Any ideas on what the scale stuff on the branches is and whether it's treatable? This will probably be the determining factor really.




Help appreciated as always

There's going to be a lot of random posts from me coming up I'm afraid, as we're clearing the garden and uncovering lots of things hiding in the undergrowth that we didn't know were there!

Okay, after days of trailing through google images, with various search terms, I've finally discovered that the 'weird growths' are meant to be there!

What I have is a Winged Elm Ulmus alata (also known as a Cork-winged Elm or, and this is the name we're going with, a Wahoo tree!) and, as they are not that common in Australia (coming from the eastern US), I'm going to try hard to save it.

This is what helped me work this out: http://pencilandleaf.blogspot.com/2009/ ... d-elm.html (the blog might be worth a look on it's own as there's some lovely sketches of plants and wildlife, along with some links in the blogroll that relate to bees, including one about aussie bees in particular)

I'll need to cut back more undergrowth the get to the other elm and see if it's the same species, but they're in a stupid place so I'm now needing to consider whether to move them or not.

Totally normal growths That is just the bark. It will be a little cork like.
I'd even say the grubs eating the leaves will be best ignored. They won't kill the tree. It will leaf up once they have moved onto a new phase of their life. It's only going to happen for a few weeks.

I know that now Fu

As for the ELB, the infestation is bad. The next phase of their life is to turn into beetles (round about now), where they will then proceed to climb back up my tree, have some more leaves, lay some eggs.... then there'll be more grubs that will eat more leaves, then climb back down the tree into the soil by the roots, where they'll turn into beetles....

I don't know how long they've been getting attacked, but they're not healthy trees and sustained stripping of their leaves every year can't be good for their health I would think

We have horses and heap the stable litter under the Elm trees. The attacks are minuscule (hardly at all), which I am told is due to the horse poo. Next door's Elms were attacked normally.

Ed

And because you feed the soil and have a much tougher tree as a result

Have a look at goodbugs.org and there may well be a natural predator for them. Have a chat with one or two of the ipm breeders on the phone about it.

We don't get many beetles on them, hardly any, so would it not be less palatable perhaps, or maybe the smell repels the beetles?
Ed

Thanks for the link Fu - I've dropped them an email.

Also just found that there is a parasitic fly that has been tested at Agriculture Victoria’s Keith Turnbull Research Institute against native and beneficial insects and was found to only attack elm leaf beetle larvae. Not sure if it's available as yet.

How pricey is it to buy beneficial insects and do you have to buy in bulk?! :S

It is no where as expensive as you may think