Your andromeda has been attacked by lace bugs. Washing them off with a heavy spray of water is a good start. Target the undersides of the leaves. Repeat every couple of days till no more dots appear. That's the bug poop. If you choose to use an insecticide neem oil would be a good choice. For more information go to Yardener.com and enter problems with andromeda in the search box. Best And Happy Yardening, Nancy. PS Be sure to keep your shrub well watered.