Douglas fir tip drop disease - what is it?

Submitted by Jeff Buster on Fri, 03/18/2011 - 16:01.

These two green 6 inch long douglas fir branch tips were two of hundreds carpeting the  ground under a 50 foot high Douglas fir last week.

I believe there is some type of a boring insect which invades the cambium right at the point of break-off.   But I couldn't distinquish what exactly invaded.

Could it be Cooley spruce gall adelgid or P. ramorium?  Problem with both gall and ramorium is that the foliage drops off brown. 

The ones I viewed on the ground were all green.   Is this just a winter snow and ice condition?  I don't think so because other nearby firs did not show same carpet of green tips on the ground.

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Douglas Fir struck by lightening

I went back to this tree - approaching from a different direction than I had approached before, and on a nearby oak I noticed that their was severe debarking caused by lightening.   I then went and re-inspected the Douglas fir, and sure enough,   on the side of the trunk was stripped bark - a companion lightening strike to the oak strike.  

The fir is also looking healthier...