Abrasive Wear in The Leg Joints of Insects

AbstractThe presence of wear of the joint cuticle of the beetle legs is demonstrated experimentally and is represented by abrasive wear. Presence of the abrasive wear in the natural‐habiting beetles of various families is also established. Abrasive wear comprises of both two‐body and three‐body wear as a result of the action of particles that have entered the joint. The presence of the sliding wear in the absence of abrasive particles is not found. The wear effects are represented by microcuttings, indentations, cracking, delamination, brittle fracturing, and destruction of the surface layer (epicuticle). The correlation of quantitative indicators of wear between the types of experimental substrates (paper, wood, sand) and the length of exposure of beetles on a particular substrate turned out to be very weak. It is hypothesized that the lubricating material in the leg joints of beetles may provide an anti‐wear function by binding particles and facilitating their removal thereby reducing surface damage by sharp asperities, and protecting the damaged surface to prevent further wear.