How to solve the transparent mucus on the back of my rich tree leaves?

The leaves of the rich tree have transparent mucus, which should be caused by scale insects or aphids.

(1) The scale insect is a small insect, most of which is covered by waxy secretions. Dioecious. The female insect has no wings, while the male insect has 1 pair of membranous front wings, and the rear wing is specialized as a balance bar. Scale insects are the most common pests in flowers, which often cluster on branches, leaves and fruits. Adults and nymphs insert needle-like mouthparts into the leaves and branches of flowers to absorb juice, which will wither the branches and even cause the whole plant to die, and can induce sooty blotch, which is extremely harmful.

(2) Aphids, also known as honey bugs and drill bugs, mostly belong to the HOMOPTERA Aphidae family, and are insect pests of suction devices. They often cluster in leaves, tender stems, flower buds, terminal buds and other parts, sucking juice, causing leaves to shrink, curl and deform, and even causing branches and leaves to wither or even the whole plant to die in serious cases. Honeydew secreted by aphids can also induce sooty blotch, virus disease and ant harm.

(3) Drug treatment: 40% omethoate 1000 times solution can be sprayed every 7- 10 days for 2-3 times continuously.