Question
All of my euonymous shrubs are dying.  They have a white substance on the bark of the bushes and the leaves are falling off.  What can I do to save the ones that are not too infested?

Answer
I believe you are dealing with an insect called scale.  They have a cottonly covering over them and they are oval in shape and do not move when feeding.  You will need to treat with an insecticide on order to save the plants.  I would treat the plant with Bayer Advanced Tree and Shrub Insecticide.  This product is mixed with water and poured on the soil around the base of the plant.  It is taken up systemically and will kill the bugs within a week or so.  It also provides protection from reinfestation for up to a year.   This should fix the problem nicely.  Good Luck.