Abstract: 【Aim】 This study aims to elucidate the creeping behavior on simulated murals of Apopestes spectrum (Esper), a dominant insect pest in Mogao Grottoes, Dunhuang, so to reveal the damage process and mechanism caused by insects to wall paintings. 【Methods】 The simulated murals were made according to the technology of ancient Dunhuang murals. The scanning electronic microscope was used to observe the microscopic morphology of A. spectrum adult crawling tarsus, the quantitative analysis was used to determine the adult wing scales and degree of pollution to murals, and the observation platform was used to record the dynamics of A. spectrum adult crawling vertically on the simulated murals. Moreover, the relationship between creeping parameters and surface roughness of murals was analyzed. 【Results】 The results showed that thoracic legs of the moth could adhere and move on mural surface by the coordination of claws, arolium, unguitractor and microtrichia, and had strong ability to creep on vertical surfaces. A. spectrum adults could creep stably on mural surface by adjusting their locomotive gait pattern. Furthermore, the roughness of murals determined whether the wing flapping was necessary for A. spectrum adults, which increased the motivation forces to make them creep stably on vertical simulated mural surfaces. 【Conclusion】 Both contact shock of claws and wings flutter of A. spectrum adults can cause damages to murals, which present more risks for wall paintings with diseases such as flaking, disruption and falling off.

Key words: Apopestes spectrum, locomotive gait, Dunhuang Mogao grottoes, simulated cave, damage mechanism