Dead Spruce Top

[Frax]

I'm trying to figure out why a spruce would have a very dead top and otherwise seem to be healthy although it may not be.
Some facts:
Mature spruce with top 6 to 8 feet completely dead. Evidence of oozing yellowy sap along main trunk. No obvious wounds or cankers or strange trunk deformations.
dead spruce top by altacal, on Flickr

Terminal cut where I cut off dead top shows area immediately above the top of the first set of live and apparently healthy branches. It's about 6 inches diameter and the detail image shows two boreholes that extend down into the live part of the tree.

terminal cut around 6 inches by altacal, on Flickr
details at terminal cut by altacal, on Flickr
Galleries and boreholes
Spruce branch galleries by altacal, on Flickr
More boreholes a bit larger than pinhole, upward facing.
Spruce branch dead by altacal, on Flickr

I realize that the insect action could be bark beetles and they could be secondary to teh reason for top die back. But I can't think of a cultural issue that causes such profound die-back from the top like this. At least I've never seen much of this in our area. I think of tree damage caused by cultual conditions to affect lower and inner growth first on conifers. But maybe this is not necessarily true. I have no history for this tree and there were no obvious reasons to suspect recent changes to anything around the tree.
Insights? Ideas to follow up?

 

[pcarborist]

Peel the bark away from the dead section and take a close up view of the gallery. Often times you can ID borers by the pattern of the gallery.

 

[Frax]

[ QUOTE ]
Peel the bark away from the dead section and take a close up view of the gallery. Often times you can ID borers by the pattern of the gallery.

[/ QUOTE ]

I plan to do this. The pieces where the bark comes off easily look like the image I show above. It's not very distinct. I may have to look at it better under bright lights.

I want to peel some bark off a dead and adjacent live section where the bark is still on tight but I don't want to destroy the trace or any larvae that might be underneath.

Does anyone have a good technique for getting bark off dead pieces when it's still stuck on?

 

[UrbanForester]

That's Pitch Mass Borer and Spruce beetle (Dendroctonus Valens) University of Guelph has the best info on PMB.

 

[pcarborist]

What I've read, D valens attacks the lower bole of the tree (usually no more than 3 ft above ground. It does not top kill.

 

[taff]

Just my nickles worth but I believe the original attack on the leader was white pine weevil (attacks Pinus sp and Picea sp but I have usually seen it on Picea glauca around Calgary. The other smaller holes are, as you suggest,probably secondary.The literature suggests that spruce/pine grown in full sun are more susceptible but I can't say I have noticed this.
Hope this helps
I'm new to the site but I have followed in the anonymous ether for some time.I enjoy all your postings and discussions.

 

[Frax]

Tx Taff
I kind of ruled that out right away. Tree is mature and the dead top is much bigger than I've ever seen on spruce. No shepherd's crook either. Aso much taller than trees usually affected. But mayb e this is weevil and just atypical. Pine weevil is the only thing I know of that kills spruce leaders here but I'm still doubting it on this case.
Do you work around Calgary?

 

[taff]

Don't work there at the moment - I'm a few time zones away in the UK - but should be back in an year or so. Worked on the grounds at Spruce Meadows, Heritage Park and U of C over the years.Was ISA certified but let it lapse - shame on me!

 

[Frax]

Aha! Bet you're from south Wales. Did I get that right?

 

[taff]

North Wales - but only for a few more months.

 

[arborcareidaho]

Frax -
Check out ips beetles. I've seen damage similar to your picture in my area caused by ips beetles. We also have high pressure from white pine weevil in our area, but I agree that the dead top is much too large to be a typical weevil hit. I am in central Idaho, but I have heard of confirmed reports of ips beetle damage similar to your photos in SE idaho, utah and colorado. Here is a link to some info:

http://www.ext.colostate.edu/pubs/insect/05558.html

hope this helps

 

[Frax]

Tx Jeff

I was looking for a critter that works the top, and what you ref may have some promising leads.
I'll get to the shop early one morning soon and bust the bark off the top which I saved and hopefully collect some dead critters to send to my friend at Northern Forestry Centre.

 

[taff]

Just wondering if you got any definitive answers on the dead spruce top?
Taff

 

[Frax]

Hi Taff

Still looking. There are live beetle larvae high on the dead leader. I have collected some, but fear they are secondary to the main cause. I've removed bark from lower on the dead stem and vertical boreholes are not yielding any critters so far. The lower dead wood is moist and has white fungal matter. This is where the bark is still tight.
I have some info that there are some bark beetles that may attack top down. Still looking and learning.

 

[taff]

Thanks for the update

 

[Frax]

Just reviewed my collection under the microscope from what I took and put the larvae and pupae in pure alcohol. I found remains of adults in the bark chunks I saved too. Will have the experts help with ID. Ips or Dendroctonus I'm supposing.
I heard another arb on the radio a couple of weeks ago saying he has been seeing some odd dead spruce tops too.
Since us arbs have eyes on so much it really helps to have a hand in investigating odd things. There are so many new invasive pests. I suppose this one could be native or expanding its range.

 

[Frax]

We are seeing more of these. There is some indication it may work itself down the stem, killing the tree.
Did a visit yesterday and HO said the tree was normal in summer and this spring top 10 feet totally dead. Other spruce close by look fine. These are full-sized seemingly otherwise healthy spruce
Is anyone else seeing suddenly dead spruce tops.
NOT white pine weevil.
I have collected beetles and larvae from under the bark for ID but these may be secondary. Not sure.

 

[nuthin_special]

All i can add to this thread is: i haven't seen that here.

Looks very unlike WPW or any dendroctonus or ips.

 

[The_Archdruid]

Ips hunteri or Ips borealis. You will find some degree of infestation in smaller lateral limbs, and the attack from the top down is frequently the case. Dendroctonus rufipennis, however, almost always attacks on the main bole, usually in the lower portion of the tree and tends to be more lethal to the host. They are both ugly little brutes and function like dangerous hillbilly brothers. Neither one is good news for your tree, but in this case, it looks like Ips.

 

[Frax]

Thanks Archdruid. I will follow up on this. Tx for the lead.