Wandoo Trunk Pits

​Greetings Fellow Foxies,
A year ago I spotted a wandoo in Candy Reserve that had large strange pits in its trunk and didn’t think too much about it until I found another example in another reserve. In this case a large branch had fallen an affected tree many years ago, leaving beautifully patterned wood after the bark had fallen off.

​Pits on the living tree are like inverted oval cones, and the damage extends up the tree to the youngest branches.

​On close examination I could see the tree’s annual growth rings on the sides and a small hole in the heartwood at the base. The sapwood was clean and clear of fungi indicating that an insect was the primary cause.
When I cut a section trough a pit I found a small (about 3mm diameter) burrow leading from the base into a more extensive gallery system in the middle of the stem.

Typical pit on trunk

Hole at base of pit

Cut atpit edge shows healthy sapwood

Enquiries have failed to produce an identification
There are similarities to wandoo crown decline as fungal canker was present in the heartwood but there are clear differences.

• This is very rare and hasn’t spread to any adjoining trees.
• The sapwood is healthy.
• I could see a ring of chew marks on the outermost sapwood layer surrounding pit which suggests that some insect comes out of the basal burrow to feed regularly.
• There must be successive generations of the insect, as indicated by the growth rings in the pits and the continuation of damage on the youngest branches

 Apart from cutting down a 200 year old tree or camping out by it and do nightly inspections, I can only ask if any of my readers can help solve this intriguing mystery
For more images click HERE