Blue spruce (Picea pungens), to be honest, is a problem tree! It is a problem tree because it is not native to Illinois; it struggles on many of our heavier clay-textured soils; it struggles during periods of drought, high-humidity, and high summer temperatures; and it is grossly over planted by homeowners, developers, and landscape companies.
Sum it all up and what you have is a problem tree that eventually succumbs to pests and pathogens due to environmental stressors such as soil drainage issues, root biomass decline, droughts, floods, and high humidity and high temperatures during the summer months.
My suggestion to all homeowners with blue spruce issues: Contact a certified arborist to determine the cause and extent of the tree's decline (this requires an on-site assessment of the problem tree).
List of Certified Arborists: http://illinoisarborist.org/services-we-provide/find-an-arborist/