Homoptera
The homopterans insects are divided into two groups: Auchenorrhyncha (cicadas, spittlebugs, fulgorids, etc. belong to them) and the Sternorrhyncha, which include aphids, whiteflies, scales, coccids, and mealybugs. Many homopterans, especially the latter ones, are considered harmful to plants because they feed on the plant's sap and destroy the plants and their fruits in general. Fruit trees and crops are the main victims of these insects. When you have noticed their activity in your garden, the best thing you can do is to get rid of them as soon as possible. Sternorrhyncha is smaller in comparison to the other group of Homoptera. Mostly they land on the host and prefer the underside to the upper part of the leaf because it is smoother, so it's easier to feed on them. For this very reason, they choose newly formed leaves.