antennae

Definition

Paired, segmented sensory appendages arising from the head of arthropods, primarily involved in olfaction, mechanoreception, and sometimes gustation or thermoreception. In insects, antennae vary dramatically in form—filiform, clubbed, plumose, serrate, or geniculate—often reflecting habitat, mating system, or feeding ecology. Crustaceans bear biramous (branched) antennae, while chelicerates (arachnids) lack antennae entirely, a key distinction in arthropod phylogeny.

Etymology

From Latin antenna, originally a sail yard; plural antennae retained in zoological usage to distinguish from electronic antennas.

Example

Male silk moths (Bombyx mori) possess large, plumose antennae densely packed with pheromone-sensitive sensilla, enabling detection of female sex attractants from kilometers downwind.

Synonyms

• feelers (informal)

Related Terms

• antenna
• Sensillum
• Flagellum
• scape
• Pedicel
• Johnston's organ
• olfaction
• mechanoreception
• chelicerate
• crustacean

Usage Notes

In entomology, the plural antennae is mandatory; antennas is reserved for electronic devices. Antennae are absent in arachnids and myriapods (except some symphylans), making their presence diagnostic for mandibulate arthropods. Segmentation terminology: scape (base), pedicel (second segment, often housing Johnston's organ in insects), and flagellum (distal segments).