Scolopidia

A scolopidium (historically, scolopophore) is the fundamental unit of a mechanoreceptor organ in insects. It is a composition of three cells: a scolopale cap cell which caps the scolopale cell, and a bipolar sensory nerve cell.

The general term of these overall sense organs is the chordotonal organs, with the scolopidia usually lying just under the exoskeleton. Scolopidia may be located within:

• the subgenual organ: located in the lower part of the legs; primarily senses vibrations in underlying substrate
• the crista acustica: collection of individually tuned scolopidia able to discriminate frequencies
• Johnston's organ: located in the antennae; senses motion of an antenna relative to the insect's body

There are many types of scolopidia, depending on the sense organ in which they belong.