Jumping plant lice

Definition

A common name for small, plant-feeding hemipteran insects in the superfamily Psylloidea, historically treated as the single family Psyllidae but now divided into seven families including Psyllidae sensu stricto, Triozidae, and others. These insects are characterized by their jumping ability, pronounced host specificity (often monophagous or oligophagous), and placement within the Sternorrhyncha alongside aphids, whiteflies, and scale insects. Nymphs typically produce waxy secretions and many species induce plant galls or cause psyllid yellows disease.

Etymology

From the habit of jumping to escape disturbance and their ecological role as plant-feeding 'lice' (an archaic term for small sap-sucking insects).

Example

The ash psyllid Psyllopsis fraxinicola is a jumping plant louse restricted to Fraxinus species, while the Asian citrus psyllid Diaphorina citri vectors the bacterium Candidatus Liberibacter asiaticus, the causative agent of citrus greening disease.

Synonyms

• Psyllids
• psyllas
• Plant lice

Related Terms

• Sternorrhyncha
• Psyllidae
• Triozidae
• host specificity
• phloem feeder
• citrus greening
• gall induction

Usage Notes

The term is somewhat misleading, as these insects are not true lice (Phthiraptera) but true bugs (Hemiptera). 'Psyllid' is preferred in technical literature, especially since the 2000s when molecular phylogenetics split the traditional Psyllidae into multiple families. The common name remains useful for general communication but should be avoided in formal taxonomic contexts. Contrast with 'aphids' (Aphidoidea), which share the Sternorrhyncha but differ in cornicle presence and life cycle complexity.