Parts of an Insect Antenna

An insect's antenna provides it with more sensory information than many other creatures gain from all their sense organs combined. When people see the antennae moving, they are actually witnessing a complex process that even the most advanced computer cannot replicate. The three parts of an insect antenna---the scape, pedicel and falgellum---work together to collect vital information for the animal's survival.

  1. Scape

    • On this grasshoper, the scape looks like a grayish base attached to the head.

      The scape attaches directly into the insect's head. It forms the base of the rest of the antenna. According to R.F. Chapman (author of "The Insects: Structure and Function"), the scape inserts into a membrane in the wall of the head. The scape attaches to a single pivot point, often called the antennifer, which allows it to move freely in all directions---not just back and forth. The antennal socket, antennal sclerite and antennal suture all help keep the antenna functioning in smooth coordination with an insect's head. These related parts, while not part of the antenna itself, are critical to its effectiveness.

    Pedicel

    • The pedicel is clearly visible on this insect; it is much longer than the scape

      The second segment, the pedicel, links the scape to the flagellum. The pedicel is part of the complex interaction of sensory information provided by the antenna as a whole. The University of Minnesota's department of entomology lists smells, sound, chemical cues, motion, orientation and even humidity among the items insect antennae can perceive. Chapman adds that the pedicel houses a specialized organ, called the Johnston's organ, which responds to the movement of the flagellum.

    Flagellum

    • Although it may appear smooth, the flagellum comprises many smaller segments.

      When an insect waves its antennae around, the flagellum becomes the most noticeable part. According to the University of Sydney's Entomology department, the flagellum is actually a chain of smaller segments called flagellomeres. These segments aid the insect with communication and navigation as well as basic sensory receptors. The flagellum has no muscles of its own, but it moves because of the other two antenna parts.

    Antenna Types

    • Insect antennae may be clubbed, feathery, hinged, bristly, pouched or any one of several other structural shapes. Each type of antenna has its own scientific name. The variations in structure and form result from differing assemblages of the three basic antenna parts. Some antennae have longer pedicels; some have more segments in the flagellum. All antennae, however, comprise the three basic parts: scape, pedicel and flagellum.