homopterans

Homopterans are a traditional designation for a diverse group of sap-feeding insects within the order Hemiptera. In older classifications they were treated as a suborder called Homoptera, but modern taxonomy regards Homoptera as a paraphyletic grouping rather than a formal clade. The insects once included are now divided mainly into two major lineages: Auchenorrhyncha, which includes cicadas, leafhoppers, planthoppers, and treehoppers, and Sternorrhyncha, which includes aphids, whiteflies, scales, mealybugs, and psyllids. Together these groups encompass many familiar plant-feeding species.

Morphology and biology are diverse, but homopterans share a common feeding strategy: they use piercing-sucking mouthparts to extract plant sap, typically from phloem or xylem. Adults and nymphs can be winged or wingless, depending on species and ecological conditions. Immature stages (nymphs) generally resemble smaller versions of adults, exhibiting gradual or incomplete metamorphosis rather than complete transformation. Many homopterans produce honeydew, a sugary excretion that can foster sooty mold and attract ants, and several species engage in mutualistic relationships with these insects.

Ecology and economic importance are notable. Because many homopterans feed on crop plants and tree hosts, they are important agricultural pests. They can cause direct damage through feeding and indirect damage by transmitting plant pathogens such as viruses, bacteria, and phytoplasmas. Their life cycles can be simple or involve alternating hosts or parthenogenetic reproduction, contributing to ecological complexity and management challenges.

Distribution is worldwide, with species occupying a wide range of habitats. The term “homopteran” remains common in informal usage, but it does not reflect a monophyletic group in current taxonomic practice.