Transmission electron microscopic study of antennal sensilla of the female black fly, Simulium arcticum (IIL-3; IIS-10.11) (Diptera: Simuliidae)
The innervation and internal ultrastructure of the antennal flagellar sensilla of female Simulium arcticum (cytotypes IIL-3 and IIS-10.11) are described from transmission electron micrographs. Two types of contact chemosensilla and at least four types of olfactory sensilla (sensilla trichodea, two or more types of sensilla basiconica, grooved pegs) were found. These correspond to sensillar types previously described from scanning electron micrographs of the antennae of these species. In addition, possible thermo- and hygro-receptive sensilla coeloconica are described from the antennal tip. The sensory complement of the simuliid antenna is compared with those of certain other dipterans, and possible roles of these sensilla in host location and other behaviours are discussed.