Dead Spruce Top

Just reread the thread and noticed Jeff's (Arborcareidaho) post with the Colorado State Extension link. That's a great resource for anything plaguing trees in the Intermountain West. Colorado has suffered devastating losses running into Biblical proportions. They have great fact sheets on everything from Ips, MPB, locusts and frogs, and fireballs of hail. If something sh*tty is happening in the woods, Colorado State Extension has a paper on it.
 

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I posted to my blog here in Calgary hoping I would find more of these and got another one today. Always mature spruce and this one was a Colorado. Hunteri attacks Colorado and borealis attacks white spruce (I think).
I agree Jeff's lead for the Colorado State Extension link looks promising.
Top 8 feet dead to a diameter of 6 inches again. HO again swears the tree was fine last summer. Beetle galleries all over the top of the main stem and side branches.
I'm going to remove the bark from today's one tonight or tomorrow and collect critters.
 
Spending my holiday Monday on work. I really want to solve this.

Pounded the bark off the dead Colorado spruce top. Collected adults and larvae. I will send them to a friend who is an entomologist in Northern Forests.
There were no traces of beetle activity in the adjacent live branches I took.
This is what the galleries look like. There isn't a piece of dead not riddled with this - all branches and main stem. No idea yet whether this is secondary or primary beetle infestation.
There are star-shaped galleries and shot-holes as well as random galleries and longitudinal ones with short side channels. These don't seem like Ips (engraver beetle) galleries in my admittedly limited experience.


Star-shaped galleries b by altacal, on Flickr


star-shaped gallery in Colorado spruce by altacal, on Flickr

and


beetle galleries in Colorado spruce by altacal, on Flickr
 
That's my best guess too. Do the galleries look typical to you. I expected them to look different.
Main question - is likely a secondary infestation opportunistically attacking a stressed top or is it the primary cause of death? How far will it go?

I can't think of a single environmental cause that causes spruce dieback from the top. But I have heard some Ips can. Maybe these are them.
 
Aren't there two beetles at work there? From my understanding ips feed only on cambial tissues but i see holes exiting the xylem.

At least there is ips or dendroctonus leaving the star shaped galleries but what is boring into the xylem. I would bet the xylem borer is your culprit.

v
 
I was wondering the same thing Vince but maybe they are just galleries that happen to be at right angles to the plane of view. Not sure. I have sectioned quite a few pieces and there are no galleries much farther than the bark and cambium layers, certainly nothing going into older wood.
Adult critters dead under the bark been sent in for ID and I have larvae in pure alcohol. Not sure what I will do with those. Unless I can find someone who can ID beetle larvae.
 
I now think the beetles are secondary. Took another one yesterday and no bugs. Just as dead. Bark spongy and crumbling. Still spots of oozing sap.
I think I need Kevin's advice on possible disease or fungal culprits. If I can't attach an image from mobile I will try this evening.
 
In reviewing the thread, is the oozing sap actually sap (watery) or pitch/resin (sticky)? When I see dead spruce tops here, I usually think of Cytospora canker, but you said there was no symptom or sign of that. Not much help, I'm afraid.
 
Hi Kevin

This tree may very well have cytospora. I am under the impression a large number of spruce have it. I see the blusih-white sappy stain I associate with this on a majority of large spruce here. I know little about this disease though.
The affected trees may also show a yellowish runny sap on the trunk. The trunk otherwise looks normal except for the dead top.

The cut end and the area under the dead bark show dark spots still oozing mainly sap, but not really gummy sap.


spruce 1 by altacal, on Flickr


spruce 1b by altacal, on Flickr

and perhaps unrelated to symptoms


Spruce 1a by altacal, on Flickr

The woundwood filling the split covered in bluish white sappy stain almost like a mineral deposit. I may not be using useful terms here either in my descriptions. My knowledge of tree diseases and fungi is amazinly deficient!

I have hit a dead end and will now try and see if I can semd samples somewhere for analysis.
 
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