Holly Bush-Infested

Question

A friend of mine has two well established Holly bushes (over 20 yrs old). They both have a white, rice shaped thing stuck to the leaves (kind of bug or disease). They are infested. I sprayed 4 times with Malathion. It does not seem to be doing much. Do you know what it is and how do I treat it? She wants to save them if she can. Nothing else around it seems to be infected.

Answer 1

It is possible that it is scale or mealybugs. I like to treat both with neem oil. It is very effective and safe. These articles will help:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/mealybugs-white-residue-on-plants-leaves.htm