a suborder of insects of the order of Homopt-era. They are small (1.5-3 mm; but in Australia they reach 6 mm) and have two pairs of wings. They can jump as well as fly and are commonly called jumping plant lice. They feed by sucking juices from living plants.
Approximately 1,500 species are known, inhabiting all continents; in the USSR there are about 300 species. The eggs are usually attached to the surface of plants by a short stem. The larvae are flat and slightly mobile. Jumping plant lice do not completely digest the plant sugars that they feed on, and their sugar-rich excrement forms “honeydew” (hence another common name in Russian, medianitsy, or “honey lice”), which attracts smut fungi that foul shoots, plants, and fruits.
Their high reproductivity has made many species extremely injurious to agricultural crops. The apple sucker (Psylla mail) and pear sucker (P. pyri) are most harmful. The larvae are the chief cause of damage: they suck the juice from plants, retarding plant growth by causing the leaves and shoots to shrivel and the buds, blossoms, and ovaries to drop off.