Ultrastructure of Antennal Sensilla of Scopula subpunctaria (Herrich-Schaeffer) (Lepidoptera: Geometridae)

In order to explore the mechanism underlying chemosensation in the tea looper, Scopula subpunctaria (Lepidoptera: Geometridae), the types, morphology, quantity and distribution of sensilla on the antenna were observed by scanning electron microscopy. The results showed that females and males antennae were filiform, bipectinate, respectively, which be divided into three segments, scape, pedical and flagellum that consisted numerous individual flagellomeres, respectively. There were eight kinds and twelve types of sensilla on the antennae, including 4 subtypes of sensilla trichodae, 2 subtypes of sensilla basiconica, sensilla chaetica, Bohm bristles, sensilla squamiformia, sensilla auricillica, sensilla coeloconica, and sensilla styloconica. No differences were found about the morphology, abundance, and distribution of most sensillum. However, the distributions and abundances of ST III, sensilla coeloconica and sensilla styloconica dimensions showed significant sexual dimorphism between male and female adults. In addition, the possible functions of sensilla were analyzed and discussed according to their morphology, distribution, and the previously reported sensilla function. These results could help to understand the chemical communication of S. subpunctaria and their host, and provide a scientific basis for the development of a novel biological control strategy of S. subpunctaria.