title: Jumping mechanisms and performance in beetles. I. Flea beetles (Coleoptera: Chrysomelidae: Alticini).
abstract: The present study analyses the anatomy, mechanics and functional morphology of the jumping apparatus, the performance and the kinematics of the natural jump of flea beetles (Coleoptera: Chrysomelidae: Galerucinae: Alticini). The kinematic parameters of the initial phase of the jump were calculated for five species from five genera (average values from minimum to maximum): acceleration 0.91-2.25 (×10(3)) m s(-2), velocity 1.48-2.80 m s(-1), time to take-off 1.35-2.25 ms, kinetic energy 2.43-16.5 µJ, G: -force 93-230. The jumping apparatus is localized in the hind legs and formed by the femur, tibia, femoro-tibial joint, modified metafemoral extensor tendon, extensor ligament, tibial flexor sclerite, and extensor and flexor muscles. The primary role of the metafemoral extensor tendon is seen in the formation of an increased attachment site for the extensor muscles. The rubber-like protein resilin was detected in the extensor ligament, i.e. a short, elastic element connecting the extensor tendon with the tibial base. The calculated specific joint power (max. 0.714 W g(-1)) of the femoro-tibial joint during the jumping movement and the fast full extension of the hind tibia (1-3 ms) suggest that jumping is performed via a catapult mechanism releasing energy that has beforehand been stored in the extensor ligament during its stretching by the extensor muscles. In addition, the morphology of the femoro-tibial joint suggests that the co-contraction of the flexor and the extensor muscles in the femur of the jumping leg is involved in this process.
authors.affiliation: Evolutionary Biology of Invertebrates, Institute of Evolution and Ecology, Universität Tübingen, Auf der Morgenstelle 28E, 72076 Tübingen, Germany k.nadein@gmail.com.
authors.forename: Konstantin
authors.identifier: 0000-0003-3937-5996
authors.initials: K
authors.lastname: Nadein
authors.affiliation: Evolutionary Biology of Invertebrates, Institute of Evolution and Ecology, Universität Tübingen, Auf der Morgenstelle 28E, 72076 Tübingen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Betz
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001517:Coleoptera / Q000033:anatomy & histology* / Q000502:physiology*; D019476:Insect Proteins / Q000378:metabolism; D008124:Locomotion; D014741:Video Recording
chemical_list: D019476:Insect Proteins; C030951:resilin
keywords: Coleoptera; Functional morphology; Jump; Kinematics; Locomotion; Resilin