Ultrastructure of a chordotonal and a sinusoidal peg organ in the antenna of larval <i>Aedes aegypti</i> (L.)

Abstract

Two specialized sensilla in the antenna of fourth-instar larvae of Aedes aegypti are described and their probable functions are speculated. One has an external peg innervated to the tip by a dendrite from a single neuron. The central portion of the dendrite is broken up into numerous fine branches within a large sinus formed by the trichogen cell around this region. The suggested function is osmo-reception. The second sensillum is of a simple chordotonal type. It is suspended within the antennal cavity and is attached within the antennal cone. Suggestions are that it functions either as a stretch receptor or as a monitor for low-frequency vibrations in the adjacent aquatic environment.