Jumping mechanisms and performance of pygmy mole crickets (Orthoptera, Tridactylidae)

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 ) 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.

Section: Functional Morphological Analysis Of the Jumping Mechanism Imentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Jumping mechanisms and performance in beetles. I. Flea beetles (Coleoptera: Chrysomelidae: Alticini)

Nadein

Betz

2016

“…By contrast, riparian arthropods frequently tread on both land and water with high efficiency using the same gaits and appendages. For example, the hydrophobic tarsi of riparian Hydrophorus flies allow them to alight on water or vegetation (Burrows, 2013), and the modified hind legs of tridactylid grasshoppers facilitate large jumps from both land and water (Burrows and Picker, 2010;Burrows and Sutton, 2012). Many spiders also locomote equally well on water and land (Stratton et al, 2004); some use a modified gait when on water while others do not (Suter and Wildman, 1999;Suter et al, 2003;Suter, 2013).…”

mentioning

confidence: 99%

Water surface locomotion in tropical canopy ants

Yanoviak

Frederick

2014

Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s −1 , with some swimming at absolute speeds >10 cm s −1 . Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants. KEY WORDS: Aquatic, Behavior, Forest, Formicidae, Neustonic, Skototaxis INTRODUCTIONEfficient locomotion at the air-water interface is relatively uncommon in nature (Vogel, 1994). Most terrestrial arthropods are helpless when they fall onto water, in part because their small body size makes them vulnerable to entrapment by surface tension forces. Additionally, the relatively low physical resistance of water to slender kicking appendages often leads to a futile struggle ending in death via drowning or predation. Conspicuous exceptions to these generalities include the specialized water-treading behaviors and morphologies of neustonic insects and spiders (Andersen, 1976;Milne and Milne, 1978;Vogel, 1994;Hu et al., 2003). For species lacking such traits, escape from the water surface usually is fortuitous.The very specialized legs of obligate pelagic and neustonic taxa such as diving beetles and water striders facilitate efficient locomotion below or on the water surface (Nachtigall, 1974), but are relatively ineffective and clumsy on land. The gaits of these insects often are kinematically distinct from the alternating tripod gait used by terrestrial species in the same clades (Andersen, 1976). By contrast, riparian arthropods frequently tread on both land and water with high efficiency using the same gaits and appendages. For example, the hydrophobic tarsi of riparian Hydrophorus flies allow them to alight on water or vegetation (Burrows, 2013), and the modified hin...

“…The shortest acceleration times occur in planthoppers and froghoppers, with take-off being achieved in about 0.8ms in Issus and Philaenus. The smallest treehoppers take longer, 1.2ms, comparable to the time taken by fleas (Sutton and Burrows, 2011) and short-legged leafhoppers , but shorter than the 2ms taken by Hackeriella (Coleorrhyncha) (Burrows et al, 2007) and pygmy mole crickets (Burrows and Picker, 2010). Heavier treehoppers take correspondingly longer so that their acceleration times of 2-3.7ms overlap with those of some long-legged leafhoppers (2.75-6.4ms).…”

Section: Jumping Performancementioning

confidence: 90%

Jumping mechanisms of treehopper insects (Hemiptera, Auchenorrhyncha, Membracidae)

Burrows

2012

SUMMARYThe kinematics and jumping performance of treehoppers (Hemiptera, Auchenorrhyncha, Membracidae) were analysed from high speed images. The eight species analysed had an 11-fold range of body mass (3.8-41mg) and a 2-fold range of body length (4.1-8.4mm). Body shape was dominated by a prothoracic helmet that projected dorsally and posteriorly over the body, and in some species forwards to form a protruding horn. Jumping was propelled by rapid depression of the trochantera of the hindlegs. The hindlegs were only 30-60% longer than the front and middle legs, and 47-94% the length of the body in different species. They were slung beneath the body and moved together in the same plane. In preparation for a jump, the hindlegs were initially levated and rotated forwards so that the femora were pressed into indentations of the coxae. The tibiae were flexed about the femora and the tarsi were placed on the ground directly beneath the lateral edges of the abdomen. Movements of the front and middle legs adjusted the angle of the body relative to the ground, but for most treehoppers this angle was small, so that the body was almost parallel to the ground. The rapid depression of the hindlegs accelerated the body to take-off in 1.2ms in the lighter treehoppers and 3.7ms in the heavier ones. Take-off velocities of 2.1-2.7ms −1 were achieved and were not correlated with body mass. In the best jumps, these performances involved accelerations of 560-2450ms −2 (g forces of 47-250), an energy expenditure of 13.5-101μJ, a power output of 12-32mW and exerted a force of 9.5-29mN. The power output per mass of muscle far exceeds the maximum active contractile limit of normal muscle. Such requirements indicate that treehoppers must be using a power amplification mechanism in a catapult-like action. Some jumps were preceded by flapping movements of the wings, but the propulsive movements of the hindlegs were crucial in achieving take-off. Supplementary material available online at