Pore-ridge nanostructures on the surface of trichoid sensilla of the male silkmoth Bombyx mori: Aerodynamic trapping and transporting of the pheromone molecules

• Published in: Arthropod structure & development 2019-09, Vol.52, p.100875-100875, Article 100875
• Main Authors: Su, Jun, Zhao, Boguang, Zhang, Aijun, Bu, Xiaoli, Chen, Jing, Yan, Zhendong, Wang, Shifa
• Format: Article
• Language: English
• Subjects: Animals; Atomic force microscope; Bombyx - metabolism; Bombyx - ultrastructure; Computational fluid dynamics; Insect; Male; Microscopy, Electron, Scanning; Pheromone; Sensilla - metabolism; Sensilla - ultrastructure; Sensillum; Sex Attractants - metabolism
• ISSN: 1467-8039; 1873-5495
• DOI: 10.1016/j.asd.2019.06.004

This paper tries to reveal the mechanism of the high-efficient adsorption of the sex pheromone by the trichoid sensilla of the male silk moth Bombyx mori. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to acquire the topographies and nanostructures of the surfaces of the trichoid sensilla. SEM and AFM images present mostly regular pore-ridge nanostructures on the sensilla, and all the pores are located at or near the feet of the ridges. AFM phase-shift images demonstrate that the variation of phase-shift, which appears along the ridge cannot simply be attributed to heterogeneity in surface lipid properties, for the phase-shift was present in the same region with the sudden difference in height. Simulations of computational fluid dynamics were applied to investigate the effects on the airflow velocity field and streamlines by the pore-ridge nanostructures and the antenna vibration. Simulation results indicate that the airflow vortexes that form on the sensillum surface are generated by the combined effect of ambient airflow and pore-ridge structure as well as spontaneous vibration of the antenna. We suggest that the vortex intercepts and traps the pheromone molecules passing nearby, and transports them through its periodical movement to the pore. We speculate that the vortex is the aerodynamic factor benefitting the highly efficient adsorption of pheromone molecules. •Sensillum surface presents mostly regular pore-ridge nanostructures.•Pores are reside at or near the feet of the ridges.•CFD Simulations were performed to study the pore-ridge aerodynamic effect.•Vortexes were generated by airflow, pore-ridge structures and antenna vibration.•Vortex traps and transports pheromone molecules to the pore.