This is not  an armored scale.  This is a "soft scale" known as a wax scale (Coccidae).  Horticultural oil does not work well against this pest.  Insecticidal soap may be an option but I have not seen any efficacy data with it against this insect.  Imidacloprid or dinotefuran work well.  Dinotefuran is rarely readily available for homeowners in Delaware and surrounding states.  Imidacloprid used to be commonly found but since it and dinotefuran are in the group of insecticides that have been associated with decreases in pollinator health it has become much more difficult to find.  If you cannot find either of those, then the rejuvenation pruning and removal of the infested branches from the area is probably your best opportunity for control.

This insect has crawler activity sometime in early June through mid-July.  There is only one generation per year in the mid-Atlantic.  In the past, this insect has survived poorly through cold winters.  This insect was much more problematic in the region years ago and two consecutive winters in a row with polar vortices drastically reduced the populations around here.  You could remove the insect and look at the underside (part attached to the plant) to see if it is black or red.  Usually, if it is black the insect has died, but if it is reddish then it is often still alive.