Question
I've had my knockout rose for several years.  The bush thrives and normally produces many clusters of beautiful red roses all summer.  The bush is about 4 ft tall and wide.  We've had much wet weather here in the Chicago area.  Today I noticed webs by the bud clusters and the buds are drying up.  Is the a spider mite problem as I've never experienced this before?

Answer
I assume you are feeding your roses?
If not then make sure roses are being fed properly .
Prune back any dead parts to encourage new growth.
Foliar spray them with any of the following :
A strong garlic spray will kill any spider mites
A strong caffeine spray will kill  any spider mites
A mild natural  Castile soap  solution will kill them too.
For garlic either buy garlic barrier.. A garlic concentrate, or make your own..buy  8 oz crushed garlic , filter out the juice, add to gallon water.
For caffeine  Make strong batch coffee, spray the hot liquid.. Won't hurt the plants.  You can also use cold brew coffee as it is strongest.
For natural soap I like Dr Bronners Lavender soap  at 1 oz per gallon water .
Let me know if this helps