There are many white bugs at the bifurcation point of Lagerstroemia indica. I heard it was a scale insect. What medicine should be used to prevent it? Has occurred in a large area, please advise!

Because there are no pictures, I don't know what pests it is. If it is a beetle, the control technology is as follows:

(1) When killing adults artificially, 90% trichlorfon 1000 can be sprayed at the peak of adults.

(2) Kill or plug with a wire hook, and dip the dichlorvos poisoned larvae in the liquid hole with a cotton ball.