Ultrastructure of Antennal Sensilla in Adults of Polyphylla gracilicornis (Blanchard) (Coleoptera: Melolonthidae)

Abscract: Polyphylla gracilicornis, both adults and larvae can produce serious damage to crops. In this experiment, the antenna structure and sensors of P. gracilicornis were specifically observed using a stereoscopic microscope and a scanning electron microscope.We also analyzed the characteristics of tentacle structure and sensor types, morphology, number and distribution of male and female adults of P. gracilicornis.The results showed that both male and female antennae consisted of scape, pedicel and flagellum. The flagellum was divided into rod-like and gill-like parts, among which the flagellum like part of the male antennae consisted of seven segments, L1, L2, L3, L4, L5, L6 and L7, while the female antennae consisted of six segments. Observations of their male and female antennal sensors revealed that both sensor types were approximately the same, with a total of seven sensor types observed, namely Sensilla trichodea, Sensilla chaetica, Sensilla basiconica, Sensilla placodea, Sensilla coeloconica, Sensilla. But, the size and distribution of the male adult antennas differed from the female antennas. The basic study of the ultrastructure of antennas provided a basis for the study of the chemical communication mechanism of P. gracilicornis.