Q. A lot of my pachysandra got white spots on the leaves and there was significant loss of plants this season. Could it be the heat and/or drought?
According to the University of Maryland Extension Service armored scale (which sounds a lot like your problem) known to be a problem on Euonymus, can also be a problem on Pachysandra. You can use a horticultural oil application now, and in spring folow up with an application of Talus or Distance, both of which are insecticides.