Fine Structure of the Sensilla Chaetica on the Antennae of Aedes aegypti (Diptera: Culicidae)1

The fine structure of the 3 types of sensilla chaetica, including the fibrillae of the male, on the antennae of male and female Aedes aegypti (L.) has been determined and compared. Although differences in size and location occur, all types have similar structure. The sensilla chaetica are innervated by one eccentrically placed neuron and have a structure generally resembling that reported from other hair mechanoreceptors, except for the occurrence of a non-membrane-bounded, spherical, lucid area in the dense material filling the extracellular space of the tormogen cell. The possible significance of this lucid area, a new observation for hair mechanoreceptors, is discussed.