What's burrowing in my Goat Willow?
Over the past few months, I’ve noticed little piles of woodchips appearing around the base of my Goat Willow. There are a few holes around the base of the trunk, and I’m concerned something is burrowing around inside it, chewing through the trunk and expelling these woodchips.
The tree is approximately 5 meters tall, and less than 17 years old. The main trunk is approximately 30 cm in diameter but quickly splits into 2 separate trunks.
Please find a full selection of photos here: http://lifebox.mobi/n86dqVK
Any ideas what this could be? Is it putting the tree at risk? If so, what can I do to save the tree?