Returning home from vacation on May 8, I noticed the pansies on the back porch looking wilted and somewhat discolored.  My first thought was that they had gotten a little too dry.  In addition, we're quickly moving to the time of year when pansies need to be replaced with hot-weather annuals, so maybe they were just collapsing at the end of their run.  Turns out it was neither drought nor old age.  A closer look revealed substantial webbing and stippling of the foliage, caused by a heavy presence of spider mites.

This late in the pansy season, there's certainly no point in making an insecticide application.  The plants were thrown out and the containers will be cleaned out before anything is replanted.  These appear to be two-spotted spider mites, which are active in warm temperatures, so there is risk of spread to other potted or landscape plants. As the NC State University information note Twospotted Spider Mites on Landscape Plants reminds us, spider mites are not actually insects, and most insecticides are ineffective in treating them.  However, insecticidal soap or horticultural oil are good options in non-commercial situations.  Be sure to read the NC State note carefully for additional information on biology and control.