Abstract: 【Aim】 This study aims to compare antennae and the types, number, and distribution of the antennal sensilla between male and female adults of the leafhopper Chlorotettix nigromaculatus, so as to lay a basis for studying the behavior biology, chemical ecology and electrophysiology of this pest. 【Methods】 The antennal morphology and the types, number, distribution and ultrastructure of antennal sensilla in C. nigromaculatus adults were observed under scanning electron microscope. 【Results】 The types, number, and distribution of the antennal sensilla are similar between male and female adults of C. nigromaculatus. The adult antenna of this leafhopper is bristle-like, and consists of scape, pedicel and flagellum. The scape and pedicel are short and wide, with numerous squamiformia denticles. The long and slender flagellum consists of 60-64 flagellomeres, and there are numerous squamiformia denticles on the 1st flagellomere. There are seven sensilla types on antennae, including Böhm bristles (BB), sensilla trichodea (ST), sensilla basiconica (SB), sensilla campaniformia (SCa), sensilla chaetica (SCh), sensilla coelocomica (SCo) and forficate sensilla (FS). Among them, the Bhm bristles are distributed on the basal scape and the lower-middle pedical, the sensilla trichodeaⅠ and Ⅱ exist on the scape, pedical and the 3rd flagellomere, the sensilla basiconica are on the tips of the 1st and 2nd flagellomeres, the sensilla campaniformia Ⅰ and Ⅱ on the basal scape and the tips of the 3rd and 5th flagellomeres, the sensilla coelocomica Ⅰ and Ⅱ on the 1st-5th flagellomeres, the sensilla trichodea Ⅰ and Ⅱ on the middle-upper pedicel and the tip of the 4th flagellomere, and the forficate sensillum on the basal pedicel. No differences were observed in the shapes and basic structures of the antennal sensilla between the male and female individuals. 【Conclusion】 The types, distribution and number of the antennal sensilla between male and female adults of C. nigromaculatus are not significantly different. The distribution of various sensilla shows certain patterns. It was the first report for this leafhopper that the Bhm bristles are located on the scape and pedicel, the sensilla trichodea and forficate sensill are distributed on the pedical, and the sensilla coelocomica are distributed on the 1st-5th flagellomeres.

Key words: Chlorotettix nigromaculatus, antenna, sensilla, ultrastructure, scanning electron microscope