It looks like white cotton cushion scale or atleast where they used to be but I can’t be sure since it’s a little blurry. It could just also be some dirt? I don’t know if any pests black and white like that and so large too. Hope more experienced gardeners chime in.

Looks like it might be whitefly to me, but a closer photo would help. Or if you have a magnifying glass to be able to check the insects with a closer view.

I placed tanglefoot bands on the trees. Hopefully if these are white flies, they will find their way onto the goo.

Tanglefoot is a barrier to keep ants from climbing up the tree, which will assist in managing the sucking insects, such as aphids, whiteflies, mealybugs, and others. Ants like the honeydew they produce and will protect them from their natural predators. You can hose off the pests on your tree. The white concentric circles on one leaf are typical of giant whitefly.