Abstract: 【Aim】 This study aims to ascertain the types and differences of sensilla on the main chemosensory organs, including the antennae, proboscis and tarsi, of female and male adults of Achelura yunnanensis, so as to lay a basis for further studies associated with chemosensory reception of this moth. 【Methods】 The morphological characteristics of the antennae, proboscis and tarsi of female and male adults of A. yunnanensis and the types and ultrastructure of sensilla on them were observed under light microscopy and scanning electron microscopy. 【Results】 Seventeen subtypes of seven types of sensilla were identified on female and male antennae of A. yunnanensis adults, including five sensilla basiconica (SB), three sensilla trichodea (ST), three sensilla chaetica (SCH), two Bhm bristles (BB), two sensilla coeloconica (SCO), one sensilla auricillica (SAU) and one sensilla squamiformia (SSQ). Among them, BBI is present only on male antennae, and ST-II, ST-III and SCO-I show sexual dimorphism in length. Five subtypes of two types of sensilla were identified on female and male proboscises, including four SB and one SCH. Of these sensilla, SB-III is distributed only on female proboscis. In addition, 13 subtypes of five types of sensilla were found on female and male tarsi, including four ST, four SB, two SSQ, two BB and one SCH. Notably, ST-I is present only on female tarsi, while SB-II and SB-III are present only on male tarsi. The lengths of SB-IV and BB-I on female and male tarsi show sexual dimorphism. 【Conclusion】 There are 17, 5 and 13 subtypes of sensilla on the antennae, proboscis and tarsi of female and male adults of A. yunnanensis, respectively. Some of these sensilla exhibit sexual dimorphism in the type, length or number.

Key words: Achelura yunnanensis; chemosensory organ, antenna, proboscis, tarsus, sensillum; morphological characteristics, ultrastructure