Which insects are traditionally included among the homopterans?

Traditionally, the order Homoptera includes a diverse group of over 32,000 species of sucking insects, all of which are plant feeders with mouthparts adapted for extracting plant sap.12

These insects are generally categorized into two large groups:

• Auchenorrhyncha: This group consists of cicadas, treehoppers, froghoppers (spittlebugs), leafhoppers, and planthoppers (including fulgorids).1
• Sternorrhyncha: This group includes aphids (plant lice), phylloxerans, coccids, scale insects, whiteflies, and mealybugs.1

While many entomologists classify Homoptera as a suborder of the order Hemiptera—alongside the Heteroptera—others argue for separate ordinal status due to distinct differences in wing structure, mouthpart attachment, and metamorphosis.3