Sensory structures (sensilla) of insects are present in high number in the antennae are important for perceiving environmental cues. Thus, sensilla play an important role in the localization, discrimination, and acceptance of a possible host by parasitoid insects. The sensilla, classified according to their shape, size, and distribution, may also show sexual dimorphism in insects. The types and distribution of antennal sensilla in female and male parasitoid Trichospilus pupivorus (Ferriere, 1930) (Hymenoptera: Eulophidae) were evaluated. T. pupivorus females had longer antennae than males. Both males and females have ten sensilla types with higher abundance of placoid sensilla in females, which suggest a possible functional dimorphism.
