Abstract:  【Aim】To clarify the types, morphology and distribution of the antennal sensilla of female and male adults of Anastatus orientalis, an indigenous parasitic natural enemy against Lycorma delicatula, and provide theoretical support for exploring the functions and olfactory mechanisms of various types of sensilla of A. orientalis.【Methods】The morphology and ultrastructure of the antennal sensilla on the female and male adults of A. orientalis were observed with scanning electron microscopy (SEM).【Results】The antennae of adult A. orientalis are geniculate, and consist of scape, pedicel and flagellum. The mean adult antenna length is 1 710.53 μm in males and 1 638.67 μm in females. SEM observation revealed that there are seven types of sensilla on the antennae of adult A. orientalis, including Böhm’s bristles (BBs), sensilla trichodea (ST), sensilla chaetica (SCh), sensilla basiconica (SB, with subtypes SBI and SBII), sensilla placodea (SP), sensilla coeloconica (SCo) and sensilla auricillica (SAu). Among them, the SAu are unique to female adults, and the smell pore (SPo) was also found on the antennae of female adults.【Conclusion】There is typical sexual dimorphism phenomenon in the types and distribution feature of antennal sensilla between the female and male adults of A. orientalis. Different types of antennal sensilla have different morphology and distribution, and play different functions. This research suggests that the abundant antennal sensilla play an important role in the process of sensing environmental changes, finding mates and locating hosts. These results lay a foundation for research on the chemical communication mechanism and olfactory behavior differences of A. orientalis.

Key words: Anastatus orientalis, antenna, sensillum, scanning electron microscope, ultrastructure