As the largest group in the animal world,insects are active in almost every ecological niche.To survive and prey,they have developed mouthparts with specific structures and functions to plunder food and even struggle with competitors through evolutions.In order to drink the internal nutritious liquid of bamboo shoot to survive,Bamboo weevils(otidognathus davidis fair)need to pierce through the thick bamboo epidermis by mouthparts.Thus bamboo weevils have developed a kind of specific mouthpart applicable to piercing through the bamboo epidermis,which has a high strength and longitudinal structure.The mechanism in bamboo weevil piercing through bamboo epidermis was experimentally investigated to inspire the bionic design.At first,the mouthpart was made into frozen sections to observe its microstructures by micro camera.Then,the interaction forces between the insects legs and substrates were measured by force sensor to calculate the pressures at the contact points between mouthparts and bamboo shoots surfaces.Additionally,a model of the broken processes of bamboo epidermis was established to analyze the balance mechanism between the body and mouthpart.The anatomic outcomes indicate that the mouthpart,which was a typical piercing-sucking mouthpart,consisted of two zygomorphous lips,a pair of upper and lower jaws and a number of fibrous needles in the center.During a bamboo weevil pierced through bamboo with its mouthpart,the two lips,which were controlled by the muscle traction,closed and reduced the actual contact area between the mouthpart and the bamboo skin to increase the contact pressure,benefiting to the damage to the bamboo shoots.Furthermore,force measurements indicated that the maximum contact pressure between mouthpart and bamboo skin correlated with the mass of bamboo weevil linearly(R 2 =0.706),demonstrating that the bigger the bamboo weevil is,the easier can it damage bamboo shoots.Through the established model,the maximum force which the weevil needed to break the bamboo shoots surface was 93.8 times its weight,much smaller than the maximum force that acted between the weevils feet and bamboo(219.3 times its weight).As an organ equipped by the bamboo weevil,the mouthpart is able to break stiff bamboos easily whereas its quiet light,which will inspire new ideas and give guidance for drilling instruments designing.The model can provide mechanical supports for the researches on the evolution of specific mouthparts of insects.