Acercaria

Definition

A superorder of insects, equivalent to Paraneoptera, characterized by reduced or absent cerci (appendages at the abdomen tip) and mandibles with a single articulation point (monocondyly). The group comprises Hemiptera (true bugs), Thysanoptera (thrips), Psocodea (lice and booklice), and the extinct order Permopsocida.

Etymology

From Latin 'acercus' (lacking a tail) + '-aria' (group), referring to the reduced or absent cerci that distinguish these insects from other polyneopteran lineages.

Example

The acercarian clade Thysanoptera (thrips) shares with Hemiptera the derived trait of asymmetrical mouthparts, though thrips retain some ancestral features lost in many true bugs.

Synonyms

• Paraneoptera

Related Terms

• Paraneoptera
• Hemiptera
• Thysanoptera
• Psocodea
• Permopsocida
• cercus
• monocondylic
• Superorder

Usage Notes

Acercaria is the older name (introduced 1895) but Paraneoptera has become preferred in modern phylogenetic literature; specialists may use them interchangeably, though Paraneoptera emphasizes the group's placement within Neoptera rather than the cercal reduction that defines Acercaria. The term is strictly taxonomic and not used in field identification.