Too bad you didn't send pictures of the entire tree.    Are branches dying from the bottom up? The pictures of the needles you sent look pretty normal, except for the webbing. That could be caused by the Spruce Spider mite. If this is an older tree, it will probably be able to survive a spider mite attack, depending on how severe the attack it. Fall yellowing of inner foliage is a natural occurrence and does not harm spruce trees.

I am forwarding a response to a similar inquiry that was received awhile back. If this does not address your question please email me back with more specific information and perhaps clearer pictures and pictures of the entire tree.

“The Colorado Blue spruce needles do have a finite life - 8 to 10 years, then they drop. So every year you can expect to see about 1/10 - 1/8 of the innermost/oldest needles turn yellowish, then brown and drop. With age, spruces become a "shell" - a support structure for needles out on the ends of branches only. For example - examining lower branches of a 40 yr-old spruce - there are about 30 years worth of growth now completely bare/devoid of needles and only 8-10 years of needles at branch extremities. Spruces may prematurely drop needles that are only a couple yrs old if they are or become excessively shaded - from branches above, from a building or from adjacent vegetation. Often, these needles turn half-yellow or whitish and half blue before turning entirely brown - this is because those excessively shaded needles are not manufacturing the green pigment chlorophyll any more (blue needle color is due to chlorophyll plus a layer of wax on the needles that helps keeps them from drying). Check a few of the buds at ends of branches to ensure they are present - they'll look a little like a small brown rose bud. These are the promise of new growth/new needles next May. Be sure to water the spruce's entire rooting area now and again during extended dry spells in winter when there is no snow cover.”

Other things to be made aware of are insects such as the Spruce Budworm. Budworm caterpillars defoliate trees. Slightly defoliated trees recover after a few years, but severely defoliated ones are degraded, attacked by secondary pests, or killed. Injury is most severe on trees that are beneath or next to large infested host trees.

Spruce Needleminers. Needleminer caterpillars tunnel into the needles of spruce trees. They cut and web needles into small, unsightly nests. Lightly infested trees recover in 2 to 3 years, but heavily infested ones may die. The green spruce needleminer and the spruce needleminer are the two most common needlemining pests of spruce.

Pine Needle Scale. This insect weakens trees by sucking sap from the needles. Severely infested trees may have sparse, discolored foliage, low vigor, and dead shoots. Without closer inspection, I did not see evidence of this.

Rhizosphaera Needlecast of Spruce. This is a fungus that causes needles to turn purplish-brown and fall prematurely, thereby reducing the vigor of the tree. Three or four years of early needle loss kills branches and, in severe cases the entire tree. This occurs most commonly on the lower branches. Most of these needles drop off by late fall.

Leucostoma Canker. This fungus (aka Cytospora Canker) usually infects trees older than 15 years that are stressed by drought, winter injury, or other diseases. Branch cankers degrade trees by killing foliage and branches. Stem cankers can eventually kill trees. It is usually accompanied by large, white patches of pitch at canker sites.  Cankers are hard to spot if pitch is not present.

As you can see, there are many possibilities. If you are still concerned about the health of your tree, you might want to contact an arborist to have it checked out on sight. http://www.treesaregood.com/treeowner/whyHireAnArborist.aspx

I hope this was helpful. Please contact us again if you have further questions.