Subgenual organ

The organ is thought to be an evolutionary artifact of ancestral insects who used their legs to detect vibrations in the underlying substrate.

All scolopidia are formed by the third larval stage and the organ has already its final shape by the time of egg hatching.

[11] The bee organ is cone shaped branching out from its nerve and almost obstructs haemolymph flow through the limb.

[12] In the carpenter ant Camponotus ligniperda, the subgenual organ has the form of a deformed sphere.

[citation needed] On one end attachment cells connect it to the cuticle; on the other it is innervated by the tibial nerve.

The organ has the shape of a cavity surrounded with a monocellular membrane that is heavily folded on the inside.

Sensory structures called chordotonal sensilla are involved in the perception of movement proper and contain a neuron per sensillum, about 40–50 in total.

[16] In Chrysoperla carnea, the green lacewing, the organ is involved in sexual behaviour and interindividual or even interspecies communication.

Three scolopidia stretch from the velum to the leg wall, each containing one sensory neuron with a dendrite and attached cilia.

The organ is appended to the forward side of the tibia and hangs into the tibial blood cavity.

Analysis of the neuronal response to vibration indicates that the organ undergoes resonance after stimulation, only slowly dampening.