Shothole Borer Beetle on Lilac?

The following was received via email:

I was researching the net as I believe our lilac tree might be suffering from Shothole borer beetle damage.

The tree (12 foot tall) was moved from a neighbours plot to our garden at the end of Summer 2004. I realise it was a was a very large specimen to try to move but we thought we would give it a chance. It has since flowered although the blooms were a bit sparce but I would imagine it was still in shock from the move. We kept it very well watered and it was feed when planted.

I noticed the damage to the bark about 6 weeks ago. Small holes appeared and also some small cracks in the bark. We cut a branch and took it to a local garden centre who told me it was not a disease that lilacs suffered from although it does look remarkably like the disease though.
Please could you advise me as to whether it is possible for this type of tree to have the disease and what I can do to prevent further damage and save the tree. The only chemical I have seen which I believe is available is Sevin.

I look forward to your reply.
Many thanks.

Debbie

 

Continue seeking local guidance. If in US try local USDA Cooperative Extension office.

 

Thanks for your message. I don't live in the states so I will try another local garden centre for advice as you suggested. I've just checked the tree and noticed that it is trying to send out new young shoots lower down the trunk despite the canopy leaves turning black/ brown and dying so I'm hoping it will survive.

 

You may like to check here: Ash and Lilac Borers, though I can find no mention of these insects in British Columbia.

Also, the BC Ministry of Agriculture and Lands Plant Diagnostic Lab is great for the truly puzzling.

 

Hi

How big was the root ball when you moved it?

Are there Ants on it ?

The reason I ask is that I have seen the same thing in the Fraser Valley of B.C/ It was caused by(my opinion) from to small a rootball and there was die back over 2 to 3 years. other insects attacked the dead dieing areas/wevels in one case

do you have rhodo's close around? If so how are they?

regards doug

 

Many thanks for all your help! I followed up the ash/lilac borer link and it shows exactly what's happening with our tree. I did notice it said an insecticidal cure was possible but would anyone know which sort of chemical I need to get. There was a chemical called Sevin listed on the Shothole Borer link I researched before but I don't know if this is available in the UK? It also said to spray/ treat in June and then 4 weeks after so do you think I am too late to do anything this year to prevent further damage? Do the beetles lay dormant in the bark over Winter?

As for the question re the rootball size. For the size of the tree yes it was extremely poor and small. We thought that the size might be another reason why the tree was struggling to establish although it is well staked and supported. Re Ants: I cannot remember seeing any ants and there are no Rhododenrons near by either.

As it is showing signs of fighting back to health I am determined to give it every chance so I much appreciate all your advice. It also blocks the view from the neighbours, the reason for us attempting to plant such a large specimen!