Q: We have three Dwarf Alberta Spruces, two of which seem to be healthy. Unfortunately, one is showing signs of some type of disease or bugs.
I have looked in several lawn books and can't come up with the problem. In the middle of the limbs the needles are turning brown and falling. There is no webbing or signs of pests.
It is however, showing signs of new growth and would appreciate any and all help you can provides so we can save the shrub.
The interior needles are supposed to be cast off as new growth continues outward. Unless the browning is within the last few inches of the tip of each branch, it seems like nothing is out of the ordinary.
If the browning is the more recent growth then you may have a problem, and it's usually spidermites. However, you haven't spotted any, nor their webbing, so I think the needle loss is probably just normal attrition due to shading out and aging of the interior needles.
But continue to check periodically for spidermites -- they can sneak in undetected.