Abstract: The antennal sensory sensilla of the parasitoid, Microplitis mediator (Haliday) (Hymenoptera: Braconidae) were observed with scanning electron microscopy. Six distinct types of sense receptors were observed, including sensilla trichodea, sensilla placodea, sensilla basiconica, sensilla chaetica, sensilla coeleoconica, and sensilla campaniformia. Two forms of sensilla trichodea and four forms of sensilla basiconica were found. Sensilla campaniformia were only found on female antennae, while sensilla basiconicaⅢ and Ⅳ only on male antennae. Their functions were discussed in reference to their morphology, distribution, and the electroantennogram responses of the parasitoid previously reported.

Key words: Microplitis mediator, antenna, sensilla, ultrastructure