Locusts use a composite of resilin and hard cuticle as an energy store for jumping and kicking

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: Fluorescence Microscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Nadein

Betz

2016

“…For example, in locusts, the structures estimated to store 57% of the energy for jumping (Bennet-Clark, 1975) are the paired semilunar processes in the distal femur, which are a composite of hard cuticle and resilin (Burrows and Sutton, 2012). These structures are bent by contractions of the extensor tibiae muscles when they are activated with other muscles in the complex motor pattern for jumping and kicking (Burrows, 1995;Godden, 1975;Heitler and Burrows, 1977).…”

Section: Introductionmentioning

confidence: 99%

Development and deposition of resilin in energy stores for locust jumping

Burrows

2016

Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle.

“…In insects such as fleas (Bennet-Clark and Lucey, 1967), flea beetles (Brackenbury and Wang, 1995) and grasshoppers (Brown, 1967), the propulsion is provided by legs arranged at the sides of the body. For example, in locusts, the energy generated by large extensor tibiae muscles is stored in cuticular distortions of the hind legs (Bennet-Clark, 1975;Burrows and Sutton, 2012). By contrast, in hemipteran bugs, the jump is propelled by short …”

Section: Jumping Mechanismsmentioning

confidence: 99%

Jumping mechanisms in lacewings (Neuroptera, Chrysopidae and Hemerobiidae)

Burrows

Dorosenko

2014

Self Cite

Lacewings launch themselves into the air by simultaneous propulsive movements of the middle and hind legs as revealed in video images captured at a rate of 1000 s −1 . These movements were powered largely by thoracic trochanteral depressor muscles but did not start from a particular preset position of these legs. Ridges on the lateral sides of the meso-and metathorax fluoresced bright blue when illuminated with ultraviolet light, suggesting the presence of the elastic protein resilin. The middle and hind legs were longer than the front legs but their femora and tibiae were narrow tubes of similar diameter. Jumps were of two types. First, those in which the body was oriented almost parallel to the ground (−7±8 deg in green lacewings, 13.7±7 deg in brown lacewings) at take-off and remained stable once animals were airborne. The wings did not move until 5 ms after take-off when flapping flight ensued. Second, were jumps in which the head pointed downwards at take-off (green lacewings, −37±3 deg; brown lacewings, −35±4 deg) and the body rotated in the pitch plane once airborne without the wings opening. The larger green lacewings (mass 9 mg, body length 10.3 mm) took 15 ms and the smaller brown lacewings (3.6 mg and 5.3 mm) 9 ms to accelerate the body to mean take-off velocities of 0.6 and 0.5 m s −1. During their fastest jumps green and brown lacewings experienced accelerations of 5.5 or 6.3 g, respectively. They required an energy expenditure of 5.6 or 0.7 μJ, a power output of 0.3 or 0.1 mW and exerted a force of 0.6 or 0.2 mN. The required power was well within the maximum active contractile limit of normal muscle, so that jumping could be produced by direct muscle contractions without a power amplification mechanism or an energy store.