Q: I found these white things on a satsuma leaf.
A: Lucky you!
You’re seeing the eggs of a lacewing. You’re lucky because lacewing larvae are ferocious predators of sapsucking aphids, scale insects, spider mites and whiteflies.
Look around on your satsuma to see if you have any of these creatures. Look also for tiny piles of “garbage” that move randomly on the leaves. These are the actual lacewing larvae hunting for a meal.
Since you don’t want to hurt these beneficial insects, don’t spray insecticides on your plant. Look for pests and wipe them off with a finger dipped in vegetable oil. You’ll probably need to hold the leaf with one hand while wiping it with the other.