Q.White Soft, Scale-Looking Infestation of Holly Bushes
Our holly bushes have deposits on the undersides of the interior leaves. They are about 1/8 inch long and 1/32 inch wide, white. They are not like the brown scale described in your info. There is no evidence of these deposits on the outside of the plants; we discovered them when we pruned the bushes down. I’m filling out your diagnostic sheet and sending a sample, but how quickly can you tell us what to do. We are worried about other neighboring plants, especially my neighbor’s hollies, which so far are unaffected.
Certified GKH Gardening Expert
This is most likely mealy bugs, the scale bug's counterpart. I would treat the plant with neem oil. It is effective against both of these bugs. Here is more information that may help you:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/mealybugs-white-residue-on-plants-leaves.htm